How hard would it be for me to replace my own brake lines?

Tiny
NIBBLYBITZ
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  • 1996 BUICK REGAL
  • 2WD
  • AUTOMATIC
  • 84,000 MILES
I've taken it to three different mechanics and for some reason, they said they had to "Fabricate new break lines" and something about lowering the cage to fix it.

I'm trying to figure out why they can't find the part somewhere and how hard it would be for me to do this repair myself, even though I have zero car fixing experience.
Thursday, February 6th, 2025 AT 4:24 PM

4 Replies

Tiny
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Here is a picture of the damage the mechanic sent me.
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Friday, February 7th, 2025 AT 6:38 AM
Tiny
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This indicates your mechanics are attempting to save you money. It is pretty much unheard of to buy the exact replacement brake line and try to install it. GM has a history of designing their vehicles to go together quickly on the assembly line with little regard to serviceability later. As such, it is common to "fabricate" new brake lines. This can be done in two ways. Most shops buy new brake line in coils of up to 25 feet. They figure out how long the new line must be, cut that off from the coil, put new threaded nuts on the ends, then form the proper type of flare on the ends. The second way that would work better for you is to buy standard-length replacement sections from any auto parts store, and piece them together.

You won't be able to run the new line right next to the old one as the old one passes through holes in the body and around places you won't be able to fish the new line through. It is perfectly acceptable to route the new line differently, but there are things we need to watch out for. The most important is to not run the new line near hot exhaust or engine parts that could cause the brake fluid to get too hot. Another caution is to avoid having the new line lay on top of sharp edges of sheet metal where it could vibrate and rub through. The new line should be anchored to hold it from sliding and vibrating.

If you want to pursue this, I'm here around this time every day to help you through it. To get started, review these articles:

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

https://www.2carpros.com/articles/how-a-brake-system-works

https://www.2carpros.com/articles/how-a-brake-master-cylinder-works

https://www.2carpros.com/articles/how-to-replace-a-brake-master-cylinder

There are many other dandy articles on this page:

https://www.2carpros.com/articles

In addition, there are more things to be aware of that only apply to GM front-wheel-drive cars. One of those is the unusual design of the master cylinder. It has a valve that trips when uneven pressures build up in the two halves of the system. That valve stops brake fluid flow to the leak, and can prevent internal damage to the master cylinder, but it has to be reset manually. That presents a problem for most people, but I have a very simple trick to do that once the repairs are done.

If the brake pedal did manage to get pushed down to the floor, the master cylinder is most likely damaged internally and will need to be replaced. That's why I included the link to that article. Many shops will automatically include the new master cylinder in their repair estimate in case it is needed, rather than tell you later that more parts are needed. The damage occurs due to the buildup of crud and corrosion in the lower halves of the bores where the pistons don't normally travel. When the brake pedal gets pushed over about halfway to the floor, the rubber lip seals run over that crud and can be ripped. That results in a slowly sinking brake pedal, and that commonly takes two or three days to show up. Some shops always replace the master cylinder as part of the repair when that is a possibility, rather than risk that problem developing a few days later. In the long run, that is a better value for you. This typically doesn't apply to a master cylinder that is less than about a year old as that corrosion hasn't had a chance to develop yet. I have another trick that can make replacing the master cylinder relatively easy and avoid the need to bleed at the other three wheels. Most competent do-it-yourselfers think they need to bleed at all four wheels. Given the age of your car, it's a good bet the bleeder screws are rusted tight and will snap off. That opens a new can of worms as to how to get the air out of the system.

If the leaking brake line is for a rear brake, it would be smart to replace both of them. Each rear wheel has a separate line that often rusts out under the left doors. When one has rusted through, the other one is just as old and is about to rust out too. Front lines are different. They run in different areas, and are affected differently by salt and water.

For the new line, when a mechanic makes the new one, he uses a special flaring tool. The common one costs around $50.00 and requires some experience to do it right. There are some newer, very expensive tools now that work really well, but take some time to learn. You can often borrow these tools from an auto parts store that rents or borrows them. In my city, they make you buy the tool, then you get a full refund when you return it. If you choose to keep it, you still return it, then they give you a brand new one.

For do-it-yourselfers, the better approach is to use premanufactured line sections. Either measure how long the line must be, or plan on making additional trips to the store. The common diameter is 3/16". You must match the type of flares on the ends. If you don't know the type, remove the ends, break them off and take them to the auto parts store. They will have a selection of lengths to add up to the total length you need. The nuts on the ends are soft metal, so "flare nut" wrenches are recommended. Also called, "line wrenches". Soft brass couplers are used to connect two line sections.

Before you start this repair, allow me to make one very important warning. That is to not allow any type of petroleum product to get into the brake fluid. Any type of engine oil, transmission fluid, power steering fluid, penetrating oil, or bearing grease will destroy the rubber parts it comes in contact with. I can describe the repair for that, but be assured the repair cost will far exceed the value of the car. Brake system specialists even wash their hands with soap and water to prevent contaminating brake parts with fingerprint grease.

Let me know if you want to pursue this. Replacing the line can be rather time-consuming, especially if you try to do this without a hoist. Bleeding the air out can also be frustrating, but I can help with that.
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Friday, February 7th, 2025 AT 4:18 PM
Tiny
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Thank you for the advice! I've decided that this car is more trouble than it's worth at this point. I'm always keen to learn a new skill, but this seems like a fairly high risk and low reward situation.
With the age of the car, I think getting a newer used car will be cheaper and less work in the long run.
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Wednesday, February 12th, 2025 AT 7:04 AM
Tiny
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This would be an easier decision if you were up here in Wisconsin where they throw a pound of salt on an ounce of snow. No car from the '90s is free of rust, and few are still on the road.

On the other hand, with the mileage you listed, there may be a lot more life left in the car. Before considering sending the car to a junkyard, you might try to sell it "as is". Replacing brake lines can be a daunting task for the average driver, but it can be handled by a competent do-it-yourselfer. It can also be a dandy project for a student in an Automotive class in a community college. Mechanics also like this type of car because we see every day the expensive repairs our customers get hit with on the newer models. You'll see more mechanics showing up to work driving rusty cars with sagging doors, cracked windshields, and torn seats. Some of us get out to kick fallen parts out of site each time we stop. We are the ones who get the last ounce of life out of a car before we send it for scrap.

I used to run into a similar situation all the time, years ago, as a TV repairman. The question would be, is it better to repair the old one or trade it for a new one?" When the decision came down to trading it in, the better value included not repairing the old one first. To explain, suppose it would cost $100.00 to fix your old tv. If you traded it in broken, you might get $50.00 off the price of the new one. Instead, if you fixed the old one for $100.00, then traded it in repaired, you might get $75.00 off the new one. It was never a better value for you to fix the old one if you intended to trade it in anyway.

Cars are similar, except many people can't handle even simple repairs like replacing bulbs or wiper blades. It is much better for the seller to do those little repairs before trying to sell the car. As a buyer, you should never listen to someone who says, "all it needs to run right is that little, inexpensive part". If that were true, they would have done it already.

Brake lines are a bigger deal. Most people will understand that this is not a simple do-it-yourself project.

If you trade your car in at a used-car dealership, they know the car is going to need a safety inspection, normal services like an oil change, and they know most cars get traded because they need a repair. That's already factored in, and leaking brake lines won't scare them or have much effect on the value they place on the car. In general, you'll get more trade-in dollars for a more expensive car you purchase. A higher priced car usually has more profit built in, allowing them to offer a higher trade-in amount.

I hope that helps. I worked at a Chrysler dealership for ten years and worked on a lot of trade-ins of all different brands. Let me know if you have more questions or need some of my wondrous advice.
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Wednesday, February 12th, 2025 AT 2:30 PM

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