Mechanics

BRAKE , ACEELERATION AND VIBRATING PROBLEMS.

2001 Toyota Camry • 95,800 miles

For last 2 months my car's brake has been stiff and I m having acceleration problems like sometimes my car's steering starts shaking very bad and when ever I short brake my car it runs smoothly, it happens once in a day. I had all kind of checkups of my car but it still having the problems.
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Kushangpathak
September 22, 2012.




The combination of symptoms suggests a sticking front brake caliper or restricted rubber flex hose.

Caradiodoc
Sep 22, 2012.
So what should I do to fix it? I have serviced my car in Walmart so many times and I even went to Toyota service but they said nothing is wrong with my car so what should I do?

Tiny
Kushangpathak
Sep 23, 2012.
When it acts up so seldom it is going to be almost impossible for a mechanic to diagnose it. No different than a doctor diagnosing you when you feel fine. All we can do is go on your observations.

One clue to a restricted flex hose is the brake pedal will be higher and harder than normal. You'll be able to force brake fluid through it by pushing on the brake pedal but the fluid won't want to return and let the caliper release.

A clue to a sticking caliper is under light pedal application the piston won't want to slide out of the caliper to apply that brake so the car will veer the other way, and under hard braking it will stop straight, then pull in the direction of the sticking caliper when you release the brake pedal. One thing to understand related to that pulling is almost all front-wheel-drive cars use what's called the "split-diagonal" hydraulic system. All cars have two hydraulic circuits; one for some stopping power in case the other one pops a leak. Since front-wheel-drive cars have such a high percentage of their weight on the front, you always want to have at least one front brake working, so one front brake and the opposite rear one are on the same hydraulic circuit instead of the two fronts together and the two rears together as on older cars and trucks. That could cause a horrendous brake pull if one hydraulic system had a leak. Alignment geometry has been modified on those cars to offset any brake pull caused by a failure in one system. Chryslers in particular have completely done away with the resulting brake pull. On other cars all you may see is a little wobble in the steering wheel when you hit the brakes when one circuit isn't working, but that's about it.

Didn't mean to get too far off topic but those are a few of the things we look for on initial test drives. Another valid test is to jack the front end off the ground, run the car in gear, lightly apply the brakes, release 'em, then see which wheel doesn't want to turn. You may even find you can barely turn one wheel by hand. You should be able to turn each one with one hand. Another simple test is to stop on a slight incline, shift to neutral, release the brake pedal, then see if the car creeps downhill on its own. If it doesn't, you have something to work with. When you get it to stick, THAT'S when there's something to diagnose.

Once it's sticking the diagnosis involves opening up the hydraulic system to the suspect brake to see if and where the brake fluid is trapped under pressure. I like to park on that incline and leave the car in neutral, then place a block of wood about six inches downhill of one of the tires. That's because I'd look silly running after the car if the brake releases! The easiest place to start is usually at the master cylinder. Use a line wrench, (also called a flare nut wrench), to loosen one of the soft metal nuts holding a steel line to the master cylinder. If nothing happens, tighten it and loosen the other one. If you see a tiny spurt of brake fluid and the car starts rolling downhill, you have a serious cause for concern. That means the fluid was trapped by an expanded rubber seal inside the master cylinder. That's due to the fluid being contaminated with a petroleum product, and it doesn't take much. That repair involves replacing everything in the hydraulic system with rubber parts, and in some cases that costs more than a ten-year-old car is worth.

Now, the good news, if loosening those steel lines doesn't let the brake release, you have a less expensive and more common problem. The next step involves crawling under the car and opening the bleeder screw on the suspect caliper. If that releases the trapped brake fluid it's almost certain to be caused by a restricted rubber brake hose. That is a real common problem on Chrysler products but it has a one-minute fix that doesn't cost anything. Your hose is of a different design but the crimp connectors on the ends can rust and expand which can constrict the hose. Opening the bleeder screw releases that trapped fluid which releases the brake.

If opening the bleeder screw still doesn't let the brake release, it is definitely a sticking caliper. That is usually an issue with age, not mileage. Rebuilt calipers are pretty cheap and they should always be replaced in pairs to maintain even braking. If it comes to that there is a big list of things I'll share that professionals do and avoid to prevent causing noises and vibrations. A good brake job is way more than just slapping in new brake pads.
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Caradiodoc
Sep 23, 2012.
After reading your reply I didn't get what should I do? Should I diagnose by myself or trade it because in a week I want my car for Long run as. In Kentucky to Pennsylvania so if the shaking continues then it is dangerous to drive so tell me what should I replace or fix?

Tiny
Kushangpathak
Sep 23, 2012.
And just to let u know when I serviced my car the service guy told me that the rod between steering and the wheel was broken and he fixed it too so now what should I do?

Tiny
Kushangpathak
Sep 23, 2012.
Most people are asking how to diagnose something themselves but if you want to leave it up to a mechanic you'll have to get the car to them when the problem is occurring, and that can be hard because they will likely be in the middle of helping another customer. You may have to leave the car and let them drive it on parts runs or even take it home at night.

The stuff I mentioned are the most common causes of what you described and experienced brake mechanics know how to find those things. I've had sticking calipers on my older muscle cars and I've had restricted flex hoses on two of my minivans and all of them acted exactly like what you're describing.

Nothing so far suggests your brake fluid is contaminated. If it was, eventually a second brake would start to drag, you'd smell the overheated brake pads, and the car would hardly move. I only mentioned that as a possibility because we do read about it on a regular basis. That contamination is almost always caused by owners who don't understand the importance of keeping grease and oils out of brake fluid. Lets not talk more about that unless other diagnosis leads us that way.

As a professional, I never like to toss parts at a problem in hopes one will solve it, but in this case if you can't get the problem to occur for a mechanic to see, I would suggest having them replace the two front brake calipers as a starting point. You must understand though there's only perhaps a 90 percent chance that will solve the problem. If it doesn't, the rubber flex hoses would be the next logical suspect. Some people get angry with their mechanic if they don't find the cause on the first visit. For some reason they don't get angry with their doctor when they have to make many visits to get a diagnosis. Mechanics are held to much higher standards than doctors.

Something has gotten lost in translation about a "steering rod". If part of the steering linkages was broken you would have run into a tree or oncoming traffic! You need a better explanation of what he found or fixed.

Caradiodoc
Sep 23, 2012.

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