When a mechanic says your brakes are at 40% is that too early to change?

It used to be common for people to say there was "15,000 miles" left in the brakes, or something like that, but that is never an accurate method because there are so many different driving habits. With mostly highway driving, it is easy for a set of brakes to last well over 100,000 miles. Mostly city driving can make that less than 20,000 miles. This is why we rate them in percent of lining remaining, then you can relate that to your driving style.

At 40 percent, if you've driven 50,000 miles so far on that set of brakes, it's easy to see they will last for multiple cross-country trips.

Some disc brake pads are rather difficult to see clearly when it comes to estimating the percentage remaining, and it is possible for one of the pads to wear faster than the others, so we don't want you to use up the pads down to 0 percent. We typically recommend new pads when the old ones are down to around 20 percent. If you have a regular shop, you always go to, they will become familiar with you and your vehicle and can better recommend service intervals that don't waste your money unnecessarily, and don't compromise safety. When we aren't familiar with your car, we have to err on the side of caution and possibly suggest a brake system service earlier to prevent problems.

Be aware too that different shops recommend different courses of action when writing up estimates for repair costs. Years ago, replacement rotors were expensive, but they could be machined and reused multiple times to true them up. Today, to save weight, brake rotors start out very thin and commonly wear down past the legal limit they can be reused. Some shops automatically include new rotors in the estimate without even bothering to measure the old ones first, then, on rare occasions, they can inform you later that new rotors weren't needed. Other shops advertise a low price for just the basic brake service, to get you to stop in there, then they tell you later the new rotors are needed at additional cost. You can end up paying a total bill that's nearly identical at both shops. It's how they present the information that's different.

By the way, the good news, when new rotors are needed, is they are very low cost compared to years ago.

You listed a mileage that less than half of what I got on one of my older Caravans before it rusted apart. I replaced the front brakes twice in that time, and the rear shoes just once. It is typical for rear drum shoes to wear out half as often as front disc pads. Your van likely has disc brakes on the rear, but they still wear at a slower rate than the front ones. Some mechanics always want to replace the brakes on all four wheels at every service, to maintain correct front-to-rear brake balance. There is logic to their thinking, however, regardless of the quality or cost of replacement brake linings, they all are required to exactly match the "coefficient of friction" of the original parts that came from the vehicle manufacturer. You can safely replace the brakes on just the front or just the rear, or both, as necessary.

Let me know if this helps or if I created more questions or confusion. If you want more details, tell me if your van still has the original brakes or if any have been replaced already.

The parts I see listed can be justified at the mileage you listed, but it is also possible they can still be okay at that mileage, so it's a judgement call unless something is obviously wrong. Anti-sway bar links are a commonly replaced part. They usually aren't very expensive and replacing them does not require an alignment.

In the 1980s it was common to rebuild brake calipers as part of a normal brake job. A pair of rebuild kits cost about ten dollars. Professionally rebuilt calipers from an auto parts store ran around $100.00 each. Today calipers cause less trouble, but when they are replaced, the rebuilt ones from the parts store can cost as little as $20.00. It doesn't make economic sense to rebuild calipers at the shop anymore.

Brake rotors have also come down a real lot in cost. We don't have to charge for the time it used to take to machine old rotors, and pay for the consumables, (cutting bits, silencer belts). We could save over a half hour of labor time that we had to charge for. New rotors today cost less and save all that labor cost.

The only thing I should mention is you may develop a brake pedal pulsation within the next few months. When we make parts out of cast iron, we set them aside for 90 days to "age" before they get their final machining. Most new rotors today come from China. There's nothing wrong with the quality, but when the Chinese make them, they cast them, machine them, pack them, ship them, then they age on your vehicle. Minor warping is very common, but a light machining will take care of that. Most auto parts stores or repair shops involved with these rotors will do that machining for free. That warping usually only happens once, usually within three months. It is even somewhat common on many new vehicles.

You covered a number of topics related to my specialty areas, but, (darn the bad luck; I forgot my reading glasses, and typing is going to be tedious for now). Let me get started with tire rotation, but it involves a discussion of what causes tire wear patterns.

There are three main alignment angles we look at. The first one is "camber". That is the inward or outward tilt of the wheel, as viewed from in front of the van, looking back at the wheel. If "positive camber" is too high, it means that wheel is tipped out too far on top. The tire will run mostly on the outer edge of the tread, leading to accelerated wear in that area. Camber always affects tire wear on only that one tire. The same is true for the other tire. Camber on that one can be out of adjustment too, but it doesn't cause the wear on the first tire.

Besides the tire wear issue, tires want to roll in the direction they're leaning. If the wheel and tire are standing perfectly straight up and down, that is 0.00 degrees. Now, if you can imagine a wheel tipped out so far on top that it is laying flat on the ground, that would be 90.00 degrees. The most common specifications for camber are typically from 0.00 to 1.00 degrees, positive. 1.00 degree is not enough that you can see it by eye. Many newer, lightweight cars have adjustable camber on the rear that often calls for very high negative camber that is easy to spot when following them down the road.

The first important tidbit for this sad story is camber on both front wheels must be in specs and equal side-to-side. A tire wants to roll in the direction it's leaning, so by being equal, those two forces offset each other and the car goes straight when you let go of the steering wheel. Now to add a tidbit to that tidbit, road surfaces slant to the right so water will run off. Vehicles will naturally drift to the right because of that "road crown". To offset that drift, we adjust in a slightly more positive camber on the left wheel compared to the right one.

The second tire wear angle is "toe". That is the direction the wheel is steering. "Toe in" means that wheel is steering toward the center of the van. At least 99 percent of car models specify very slight "total toe in". Road forces are expected to pull the wheels back a little while driving and braking, with the goal to have exactly 0.00 inches of toe-in. That means both wheels are exactly parallel to each other, resulting in no toe wear. "Total toe" just means we look at both wheels together as that is what determines tire wear related to that angle. I can add to this wondrous topic later if you want me to, but for now, if toe is equal on both sides, (and on the rear on vehicles where it is adjustable), the steering wheel will be straight. When total toe is not in specs, it always causes bad tire wear patterns on both tires on that axle, even if toe on just one wheel is wrong.

When total toe is too much "toe-in", a choppy pattern will develop on the outer edges of both tires. You can feel that when running your fingertips both ways around the tire. One way your hand will glide over the high spots, but the other way your fingers will tend to catch on the raised blocks of rubber. By "reading" those wear patterns, we can figure out which alignment angle is not correct and what we can expect to need to do to fix it.

When total toe is negative, or "toed-out", the wheels are steering away from the center of the vehicle. That results in the choppy, or "feather-edge" pattern developing on the inner edges of the tread. This makes for a really miserable vehicle to drive in strong cross winds. When the wind blows to the right, it pushes the vehicle, then more weight is transferred to the right tires. The vehicle wants to follow the tire with the most weight on it. In this case with toe-out, it follows the right tire to exaggerate what the wind is already doing.

The third angle is "caster". This one is very hard to explain. I used to tell my students there were at least five ways to explain caster and what it causes. I'd start with the first explanation on Monday. I never had to go beyond Thursday before everyone understood it. Visual aids helped.

Since you won't be tested on this later, let me start by saying alignment specialists do not consider caster to be a tire wear angle, however, for the benefit of others researching this topic who might see this, when taking the written exam for ASE certification, they DO consider caster to be related to tire wear. One of the explanations revolves around how caster makes the left front wheel tip out on top more when it's turned to the left. That tipping makes that tire run mostly on the outer edge of the tread, therefore, that edge wears faster. My reply is while that might be true, how many miles do those tires see when zig zagging back ad forth through a parking lot? That is where this type of wear is observed.

Caster has to do with the orientation of the steering pivot points for each front wheel, as viewed from the side of the vehicle. Think of the front fork on a bicycle and how it angles rearward at the top. By putting weight on it, that makes the wheel want to squirt out straight ahead and is what makes you able to ride no-handed.

On older, heavy rear-wheel-drive cars and trucks from the 1960s and '70s, positive caster, meaning the upper ball joint was further back than the lower ball joint, made each wheel want to steer toward the center of the vehicle, so hard in fact, that it was almost impossible to pull one back to straight ahead by hand. It's when you connect the two sides together with the steering linkage that the two forces offset each other. Caster had to be equal on both sides, although we could adjust in slightly higher caster on the right to offset road crown, rather than using camber for that. Some cars were so hard to get adjusted exactly what we wanted them to, that we settled for what we got for caster and camber once both were in specs for both wheels and they'd give us the road crown offset we needed. My only reason for including that confusing statement is to say you could find two identical car models with different camber and caster settings, and both would go straight, with a straight steering wheel, and good tire wear.

When we get to newer vehicles like my '88 Grand Caravan, and yours, no one in the universe I've ever discussed this with knows why, but almost all front-wheel-drive vehicles are not affected by unequal caster. I even had one with 3.00 degrees difference, and it went straight down the road. For circle-track race cars, 3.00 degrees is enough to make the car go around left-hand turns without touching the steering wheel. Because caster has no effect on most front-wheel-drive vehicles, it is not adjustable. It still gets measured automatically by all alignment computers, but we don't pay attention to it like we do with camber and toe.

Finally, as for the need to for tire rotation, let me cover this from the worst case to, ... Uhm, ... The worst case. By far the world's worst model for tire wear was the Ford-built Escort from the 1980s. As I eluded to in my exciting discussion of camber, the typical range of manufacturer's specifications was close to 0.00 degrees up to as high as 1.00 degree. One full degree was pushing it as that was starting to put too much weight on just the tire's outer edge. We like to stay closer to no higher than around half a degree. The Escort called for a mind-numbing 2 7/16 degree on the left wheel, and it was not adjustable. Being the well-trained experts we were, the tendency was we wanted to stand those wheels up straighter, but we couldn't. Those angles were chosen by the engineers because it made the front tires run on just the tiniest outer edge of the tread, then since the sidewall had to flex so much, (leading to dangerous heat build-up), the ride quality approached that of old, heavy cars. They rode so much smoother than those of their competitors, so they sold a pile of them. The rear wheels were just as bad, but they called for excessive negative camber, so those wore out on the inner edges. What every Ford salesman knew, but didn't tell you, was a set of tires could just barely last 15,000 miles. If you complained, you were told you didn't rotate them enough. If you did have them rotated every 6,000 miles as specified in the owner's manual, they might last 18,000 miles. I knew two owners of tire franchises. Both said tire mileage warranties did not apply to Escorts. The tire manufacturers said their tires were being used in an abnormal manner, and on those cars, were expected to wear out much too quickly.

At least on the rear of Escorts, we could install an under-size bolt and a wedge to stand those wheels up straighter, but it didn't make the tires last any longer. So this was the very well-known worst case for tire rotation being of little value. Couple that with their outer tie rod ends that very commonly failed at 15,000 miles, and it's easy to understand why so many mechanics don't trust Ford products to put their families in. When I worked at a Sears Auto Center in the 1980s, we got in a shipment of steering and suspension parts to restock our shelves every Wednesday afternoon. We'd get perhaps a dozen parts for GM cars, a dozen or so for Chrysler products, about a half dozen for all import models combined, and besides all the other Ford parts, we'd get 44 Escort outer tie rod ends, and those were sold by Saturday and we had to order from the local parts stores until our next shipment came in. It was very common for those tie rod ends to separate, again, at around 15,000 miles, leading to loss of control and a crash. Depending on which one fell apart, you'd go into the ditch or into oncoming traffic, so we called them, "killer cars". Ford has had a history of bad designs, so I get a little nervous every time I see one coming at me on the highway.

A problem that we could solve was a choppy pattern on the right front tire on Ford two-wheel-drive full-size vans and pickup trucks. Regular rotations did reduce that wear by distributing it to all of the tires, but the real solution was a simple rubber bushing made of a more solid compound, and stiffer shock absorbers. The Ford engineers couldn't figure that one out either. It took the aftermarket industry, (Moog / Federal Mogul), to develop the solution.

For most people, the tire rotation is a maintenance performed once or maybe twice a year. Front-wheel-drive vehicles have a higher percentage of total weight on the front, so those tires tend to wear faster. The thinking is by rotating them periodically, all four will wear out at the same time.

The other end of the worst cases is the way I handle tires on my own vehicles. Currently those are a 2014 Ram, 2014 Caravan, 1994 Grand Voyager, 1993 Dynasty, (less than 5,000 miles), and a 1980 Volare. On every one, I have never rotated any of the tires. In fact, three on the Volare are still original and have never been off the car since I bought it new. My thinking is the rear tires tend to wear faster on rear-wheel-drive cars, then I'll buy just two new tires, not four. I buy half as many tires at a time, but twice as often.

This thinking is not really valid when anti-lock brakes started showing up. I have them on the Dynasty and the two newer models. Wth ABS, the computer watches the rotational speeds of each wheel to figure out when it has to do its thing. This usually isn't a problem when you buy only two new tires at a time, but there are a few models where that is absolutely the wrong thing to do. The four-wheel-drive Chevy Astro Van, and at least one Jeep model use a full-time system where the front and rear driveshafts are always locked together. Simply going around a gentle curve in the highway puts those transfer cases into a very stressful situation, but only temporarily. Mismatched tire sizes causes that stress constantly and leads to a failure of the transfer case. There have been lawsuits resulting from tire dealers selling only two new tires instead of all four that are perfectly matched. I don't know what the history has been or the prevailing thinking regarding periodic rotation, but I would suspect it's more important on these models to ensure tire outer circumferences remain the same.

To boil this all down, I wouldn't hold it against you if you chose to never rotate the tires, as long as any unacceptable wear patterns were addressed with an alignment. By the way, I personally own two alignment computers, but I haven't aligned any of my vehicles since I allowed students to use them for learning exercises. That ended in 2008. My 2014 Ram was a crash rebuilder. That one did get aligned by someone else. He left it with a very slightly off-center steering wheel. Had I been doing the alignment for someone else, I would have taken the time to correct that, but in this case I chose to ignore it.

I also wouldn't fault you for having the tires rotated, but today we put miles on so fast, I'd recommend going by time of year rather than mileage. Rotating tires is meant to distribute wear evenly among all of them. I prefer to do what I can to eliminate or reduce objectionable wear, but I also have a fault where I run tires until I can just about see the air inside them. I don't recommend waiting that long to replace them.

Now that I shared all that glorious information, it occurs to me I overlooked some important comments of value. Most importantly my last reply was all about tire wear and the alignment angles that contribute to it. I should have mentioned there are other things we need to look for. One is simply the tires. Each one has its own rolling resistance, and that can change over time. When a pull to one side develops gradually and gets progressively worse over weeks or months, the first thing I like to do is switch the two front wheels / tires side-to-side, then go on a test-drive to see if the vehicle pulls the other way. If it does, but those tires aren't worn to the point of needing replacement, I switch them front-to-rear and never rotate them after that. I make it a point to explain to the owner why this solved the pull, and why these tires shouldn't be rotated again. Sometimes switching the tires makes the vehicle pull the other way, but most of the time it goes straight, then there's no need to switch them front-to-rear.

Chassis ride height also plays a part in tire wear. All alignment shops have small books that list every car and truck model, and where to take the measurements. Reputable shops will not take your money for an alignment if the vehicle is sitting low due to old springs, but that is less of a problem now than it was with older cars. The front suspension system on old rear-wheel-drive cars was very heavy, expensive, and complicated, but it offered superior ride quality. All of the parts formed a very specific geometric relationship, similar to a square, but with unequal length sides. The design caused each front wheel to tip in and out on top as the car body bounced up and down. Tire wear was excellent as long as ride height was correct. When the springs sagged from age, (not mileage), the relationship of that square changed. The two control arms went through wildly different arcs as the body bounced up and down. What that meant in simple terms was all the numbers on the alignment computer's screen could be "green", meaning "in specs", but if ride height had sagged, you'd still have rapid tire wear. Rather than the tire tipping back and forth, as designed, to distribute that wear, it scrubbed left and right across the road surface as the car bounced. The wear patterns looked acceptable, but the tread wore out too quickly.

Your van, and most front-wheel-drive vehicles use a strut front suspension which is more forgiving of sagged ride height. We still check it; in fact many newer alignment computers incorporate a method to measure ride height, but we don't get quite so excited if it's low. We can still do the alignment with no concern for accelerated tire wear.

Related to ride height is how the vehicle is loaded. This is a bigger concern on vehicles with independent rear suspension, because the amount of weight it's hauling changes that geometric relationship the suspension parts travel through as the vehicle bounces. If the trunk is normally empty, that is how it should be when the vehicle is aligned, even if it will be fully-loaded for your vacation trip. If you always carry a lot of salesmen's samples, or if you normally car pool or haul the neighbors kids to school, that is how the van should be loaded with similar weight while it's being aligned.

The last thing for this chapter has to do with tire pressures. There are multiple ways of approaching this, one being to go by the pressures listed on the door sticker. That got Ford into a lot of lawsuits by them recommending pressures much too low, to increase ride comfort, but it caused excessive sidewall flexing, heat build-up, blowouts, and crashes.

All tires have their maximum pressures listed in very tiny numbers on the sidewalls. That's the highest they want when the tire is cold. It can be allowed to go higher after a long run at highway speed. The problem is different tire brands have different maximum ratings. I had almost no complaints of ride harshness when I put tires rated at 35 psi max to 35 psi, and the same, if a tire was rated at 44 psi max, I put them at 40 psi. Both of these were with no regard to what was listed on the door sticker. Reasoning is, that sticker has to be valid for any brand of legal tire you might buy. For example, if a 44 psi tire was comfortable being set at 40 psi, and they put that on the door sticker, what now when you bought a set of tires rated at 35 psi max? At 40 psi, they'd be over-inflated, possibly leading to a blow-out, a crash, and a lawsuit. That's why I always went by the tire, not the door sticker.

An over-inflated tire causes the center of the tread to bulge out. Being the only section that hits the road surface, that is what wears out fastest. Both edges have more tread. Of course, the opposite happens when the tire is under-inflated. The center sinks in, then all the wear takes place on the edges. That can look similar to camber wear, except camber wear only occurs on one side. This is where we have to start thinking about the combination of causes and the mix of wear patterns that can develop. The patterns I described basically refer to starting with a vehicle where all four wheels are in perfect alignment, then we discuss just one variable at a time that is out of adjustment. Sometimes with a combination of causes, we have no choice but to just start the alignment, look at the preliminary numbers, then relate them to the tire wear we see. For you and any competent do-it-yourselfer, you have only two things to look for. That is smooth, even, acceptable tire wear, or not. Since this is one of my specialty areas, I was in the habit of feeling and examining the tires on every vehicle I walked past in the shop. When I found something to be concerned about, I'd briefly mention to that mechanic that he might want to make a note on the repair order to suggest an alignment or at least a suspension and alignment inspection. For some car models, an inspection once a year is a good investment, while others can go a couple of years. There is no common parts failure history for your van, so I would be comfortable with the mechanic's brief glance at the tire wear patterns during other routine services such as oil changes.

The only other thing to be aware of, when a part wears, or an alignment adjustment slips or changes, is pulling to one side, and an off-center steering wheel show up right away, including right away on the test drive after I completed the alignment. Unacceptable tire wear takes mileage to show up. You might not see evidence of that for many months. If you rotate the tires before that wear shows up, you may never know something is out of adjustment.

Normally by this time I would have asked you to start a new question for each topic, for two reasons. First, these get categorized by topic and car model so others researching the same symptoms or problem can read your solution. This thread may have their solution, but they won't read it if it starts out on some other unrelated topic.

Second, while it is possible for our other experts to follow along on the side to learn what we figured out, they often could produce a much better reply, but, unlike on other forums where anyone can chime in to confuse the issue, here this basically becomes a private conversation between the two of us. We will stick with someone, even for months when necessary, but for the most part, the other experts won't see our conversation or have a chance to post a reply or addition. Often that doesn't get you the help you need or the best response. By starting new questions, they all have a chance to read it and decide if they feel comfortable seeing the problem through to a solution.

I'm going to continue on here because the topics are related and don't really have their own separate categories, but feel free to start new questions if you think it's appropriate. The link for that is:

https://www.2carpros.com/questions/new

Stay tuned for the next exciting chapter. I'll type that up tonight, then post it tomorrow for your reading pleasure

I just saw that we overlapped with replies. I didn't read your last one yet, but I saved a copy to read at home tonight. I'll put together some thoughts, then post them tomorrow. In the meantime, here's links to some related articles you might find of interest:

https://www.2carpros.com/articles/avoiding-car-repair-fraud-58849599

https://www.2carpros.com/articles/basic-car-safety-inspection

https://www.2carpros.com/articles/how-car-tires-work

One comment to finish up on rotations, when "reading" tire wear, I need to know if the tires were recently rotated as the wear I see on the left rear, for example, might have occurred while it was on the left front. Related, if a mechanic can't tell if the tires were rotated recently or not, they probably don't need to be rotated now.

On to new business. Circumstances can vary, but in general we don't approve of providing your own parts. I equate that to bringing your own food to a restaurant and asking them to cook it for you. If you aren't satisfied, who is to blame? When the shop provides parts, first they have to inspect or diagnose systems to determine what is needed. We will never defend a disreputable mechanic or shop that pushes unneeded parts, but that's a topic for another day. Some parts, like a burst rubber brake flex hose is quite evident. It must be replaced. That same hose can instead develop a dry-rotted and cracked outer casing. That can sit that way for months or even years, but at some point someone is going to catch that and recommend replacement. We know that hose is rotting away and is going to pop eventually. Do we ignore it and hope it lasts a few more months, or would you want to know about it and have it replaced before it pops, leading to loss of half of the brakes? Without going into a lot of detail right now, a blown brake hose can lead to further damage, namely a damaged master cylinder. No one wants to wait for the catastrophic event to occur. We will want to replace that hose now. Next, what if that hose's outer casing isn't cracked yet, but upon inspection, the dry-rot is evident. A conscientious mechanic who is not familiar with you or your van might want to be safe and recommend new hoses now, in case he never sees that van again. A mechanic you visit on a regular basis might not say anything right now, to save you money, but since you come in often, he will keep an eye on that hose, and recommend a new one before it becomes a potential safety issue. This is one reason why different mechanics find different worn parts at different times.

Another type of problem involves things like anti-sway bar links and bushings. All those parts could be removed and you likely wouldn't notice. But, bushings, in particular, can wear away allowing the bar to thump back and forth inside them. That is an irritation, but not a safety concern. We can legitimately recommend replacing them, but we understand for some people dollars are tight and better spent on food and rent. This is something that can be ignored. Some things are judgement calls as to how serious of a problem it is or could cause, so there's another variable between shops and mechanics.

Getting back to who provides the parts, the shop gets your approval before spending your money, then they have those parts in stock or they call a local parts store to have them delivered. They look at their cost, then mark them up a little. That profit helps to cover their cost if that part is defective or the wrong one, and they have to reorder. That additional cost is not passed on to you. If a new steering part fails, or even causes a new noise, the parts profit covers getting the replacement, and it covers the second alignment. You are not expected to pay for a second alignment. In this case, if the mechanic made a mistake or damaged the part, he has to make it right but doesn't get paid a second time. He works for free on your job, and he loses again by not being able to move on to the next job. The shop loses too.

When the fault lies with the part that failed during the warranty period, you, again, are not expected to pay the second time, but you do have to take the time to bring the vehicle back. When the mechanic is not at fault, he deserves to be paid to do the job over, along with another alignment if appropriate. The shop owner knows it's inappropriate to ask you to pay a second time, but he expects to have to pay his mechanic. Those dollars come from the parts profit.

Also consider that we often think we've diagnosed the cause of a problem, but the only way to be sure is to replace parts. If we guessed wrong, it is not proper to make you pay for that part, but often we can't return them to the parts store. Those parts go on our shelves for the next customer who needs them, but that can take years. Look at the thousands of dollars a Walmart store takes in each day, but also look at the millions of dollars in inventory sitting on the shelves to make that possible. Every part sitting on my boss's shelves represents breakfast not on his table tomorrow. The little profit once he does sell that part reduces the impact on the bottom line. Some shops even mark parts prices up based on what they paid for it two or three years ago, rather than basing it on the current price after inflation is factored in. That can save the customer a few bucks.

Now for the exception. Especially with old or classic cars, a shop or mechanic may ask you to provide the parts. Finding parts may be very time consuming. You get to decide how much you want to spend on quality, or which is the better value when factoring in shipping costs. The first problem is what if the part doesn't solve a problem. You own it. Now it may sit on your shelf, representing one less trip to Burger King. If the part is wrong or it fails, you take on the responsibility of getting it replaced. Also, since the shop has no financial involvement with that part, if another replacement is needed, you can be expected to pay for a second alignment. Once I learned all the things I take on, letting the shop sell me the parts didn't look so bad.

The TIPM you mentioned, (totally integrated power module), is a fancy name for the under-hood fuse box. We've been complaining about the manufacturers using way too much unnecessary technology for many years, and this is a perfect example. A few models have computer electronics in them, but many do not. Those that do not are "plug and play". Plug the new one in and no programming is required. This is one module I would prefer to get a new one right from Chrysler. Unlike most modules, this one does have a high failure rate. Chrysler has a history of redesigning parts to improve quality or improve reliability. When you buy a used one, you get the same thing that just failed on your van. That used replacement might be okay now, but a repeat failure can be expected. What you can do is look at the part number on the sticker on the module. The number on the first run will end with an "AA". When a significant change or improvement is made, the number changes to "AB". It's pretty common, in my other line of work with car radios, to find model numbers as high as "AG" or "AH'.

Eventually so many updates or changes are made that a module warrants an entirely new part number. That can even be an old module that has been rebuilt by one of the companies that do that. They will add a sticker with that new number. The point is you may get a replacement module with a different part number. The best approach is to go by application, not necessarily part numbers.

For the other parts you mentioned, Chrysler used a lot of small Nippendenso starters in the '90s. They could also be installed in place of the older style from Bosch. The Nippendenso had a very common failure in the internal switching contacts would burn away. Most people just replaced the starter, but those contacts can be replaced for $6.00 for the pair. I've done this twice on my vehicles, but it's important to note this problem always starts out as a very intermittent failure to crank the engine. Turn the ignition switch to "crank" and you'll hear one rather loud clunk, but that's all. Try it again and the starter will work fine, often for weeks before it acts up again. As the contacts continue arcing away, the problem occurs more frequently, but you have plenty of warning before this becomes permanent. The last time this occurred to my mother's Caravan, she lost count after turning the ignition switch 700 times, but it did eventually start. You can be sure I heard about it that night, and about the blister on her thumb. The problem first began showing up about a year earlier.

To my knowledge, there is no common failure history with the newer starters.

Tire sensors are new to me. After ten years at the dealership, I left before they became common, so I never got any factory training on them. I put up with one of them on my truck not working for over three years, until less than a month ago. I have a friend with a body / repair shop. He put in a new sensor which solved that problem, but I found out later it cost him around $12.00. I treated him to lunch to pay for the sensor. Since then I also learned a lot of shops do charge a lot because it takes special equipment to mount tires without damaging those sensors, and it takes expensive tools to program the sensors to the computer that talks to them. Shops have to charge when they use that equipment, and by the time it gets paid for, it's time to upgrade to something newer that works on the latest models. That doesn't mean your regular mechanic has to charge for equipment usage, but it can be justified. $100.00 seems very high for one sensor. I have a suspicion there was some diagnostic time involved, or more than one sensor was replaced. At a recent trip to a tire and alignment shop, they had listed $18.00 labor to replace a sensor when they were already removing an old tire and installing a new one. That didn't include the sensor itself.

I was surprised to see the injectors were replaced. It would be nice to know why. I've never heard of an injector problem on any Chrysler gas engine. Of the ten most common injector problems, eight are on GM engines and two are on imports. GM grabs six or eight injectors out of a large bin, and throws them in with no regard to "flow-matching". By around 100,000 miles, one or two flow a lower fuel volume compared to the others resulting in diagnostic fault codes related to cylinder misfires. Chrysler buys their injectors in flow-matched sets from Bosch and has no problems. In fact, my '88 Caravan has over 440,000 miles with the original injectors. I'm not saying there was nothing wrong with your injectors. Just saying failures are extremely uncommon.

For the last two things you mentioned, I'd refer you to a nearby community college with an Automotive program. First, for inexpensive repairs, we used to charge $10.00 per hour for what the job was supposed to take according to the "flat rate" guide. More on that later if you ask. We also got parts at nice discounts, then marked them up ten percent to form our "breakage" fund in case we damaged something. The kids were very responsible and well supervised. We had about two dozen community members who would sit on a broken car until it fit what we were teaching, because they knew the value those had for our learning experiences. The advantage is the low cost. The trade-off is it can take a really long time to get the vehicle back. We only had four hours together each day and a few of those were spent in the class room. Each of my four areas was taught just once a year, for eight weeks. The first few were spent learning the subject matter, then we had a few weeks of practice on live cars. We would not work on a steering / suspension problem during Electrical class, for example, partly because eight weeks was tight for packing in the subject matter so we had to stick to the topic, and partly because working on anything out of the class being taught would take work away from the shops that hired our graduates. We had a dandy relationship with the shop owners and didn't want to jeopardize that.

If you're interested in doing some of your own repairs, the place I'd start is with reading some text books. Instructors get samples mailed to them every year in hopes we'd adopt them for our classes. We gave a lot of those away to our local tax payers. For our program to be certified, one of the requirements is the text books can't be more than five years old. That means we have a lot of older ones we can't use, but the information is still relevant. Talk with the instructors to see if they have a text book you can have or at least borrow. You can find the text books in the school book store too, but I don't recommend that due to the cost. Most of them cost more than $125.00.

Besides our list of articles, we have a lot of training videos, but I don't think there's an index other than the one I put together for myself. The problem with videos is they're really meant for people who already know how to do a task, like change the oil, but not on a certain model. Perhaps a brake job is a better example because there are so many different variations in procedures.

While you're at that community college, inquire if they offer night school classes. My school used to offer an open shop class two nights per week for anyone in the community. There was no formal training, no testing, and no grades, but the instructor was there to help and offer guidance. Those nights you could work on whatever you wanted to, as long as you demonstrated proficiency on the equipment. To support our program, one fellow came in each night just to wash his two cars. Even some students signed up to get extra shop time. Some students are happy to work with you and show you what to do. Or, ... You can enlist a student to do the work while you sit and watch.

Finally, since our program was divided into eight, eight-week sessions over two years, it was open for a person to sign up for just one class. No math class, no degree, just a certificate of completion and the exact same training on the one subject that the rest of the class got.

Keep in mind mechanics go through more training than doctors do. Doctors only have to learn two models in varying sizes. Only the cures change over time. Doctors bury their mistakes. Mechanics have to learn new models, often twice per year, and all the new systems and problems. Our mistakes keep coming back until we find the solution.

That's today's story. Let me know if you'd like me to expand on any topic.