Write-Up: Brake Line Repair

Can someone explain to me what this rubber coating is or if this is how the brake line is suppose to look?

It's probably a protective shield of some kind. I wouldn't worry too much about replacing it.

Thank you AA.

Is it necessary to replace the entire length or would it be possible to use a tube cutter and a compression fitting and just replace a section of the line?

You can replace part of the line, but I would use the double flare tool and threaded fittings. Never trust compression fittings with brake line pressures (1000-2000 PSI).

Check the condition of the brake fluid. If it is black or rusty, I would replace the entire line, as it probably rusted from the inside out. You just don't know how bad things might be inside the line. Or, if the line appears in better shape upstream, you can try cutting it at the good spot, and flaring the end. If it flares okay, it might be all right.

Ironically enough, that rubber coating is from the factory to help prevent what has happened to you. You can buy that exact stuff at the store. It's more expensive, but available. Problem is, you have to strip that stuff back in order to flare the line anyway, which leaves it open to the elements. From the factory that coating goes all the way into the fitting.

I had to splice in a section of new line to the Park Ave. I owned.
Bought a 2 foot section of line at the auto parts store, and a double flare tool form Harbor Freight.
(I am fortunate, or perhaps cursed to have one within a mile of my house.)
Not the funnest job.
Be sweet if you could find a new pre-bent line.

Thanks for all the tips.

AA, I want a SAE (Standard) double flaring tool don't I? From what I've found the lines are 3/16 but I just want to verify.

Yeah, they are all the same, I think. Should look something like this:



3/16" sounds right, but I've read the fittings are metric, so be sure to match the threads up.

Yeah, GM has a BAD habit of using standard line with metric fittings/threads. I've had to buy standard line, cut the end off, put the metric fitting on, and then flare the line. It's stupid. Most parts stores don't carry standard line with metric fittings either.

I think it's only a single flare. The double flare looks like a mushroom. But, a SAE Double flaring tool will make anything you need for the Riv.

The double flare tool is what you want. You can identify it by the black insert pieces (shown above), which is what lets you make the double flare.

Gotcha, I'll be renting it along with a bending tool.

Does anyone who has replaced a line know what size flare wrench I'll need for the fittings?

manofmany wrote:

Gotcha, I'll be renting it along with a bending tool.

Does anyone who has replaced a line know what size flare wrench I'll need for the fittings?

The new ones that you end up buying could very well be different size nuts than your existing fittings, the threaded part being the same.
So, if you don't want to buy a set of Flare Nut wrenches then you can buy the individual ones you may need for assembly when you get the fittings from the auto parts store or wherever you choose to buy them. Or you may be able to get away with regular wrenches for the assembly of all new parts, Although having a set of Flare Nut wrenches in your toolbox is always a good thing to have. Start with a Metric set and then buy American set when you can and you'll be ready for any problem you mat encounter. Be it at the Fuel Filter (always a rusty mess in the snow belt) or Radiator for Trans lines, etc.
If I remember correctly when I did my brake lines they were Metric in size. Can't remember for sure, because I have both Metric and American tools.

I replaced mine from the front to the rear, complete replacement of all lines.

From your pics of your lines failing in the middle of the car, a good place to pick up on a threaded fitting would be to replace your lines from the Proportioning Valves (cylindrical units) located in each brake line on the right passenger side closer to the front of the car all the way back to the calipers at each rear wheel. If that is the approach your going to take then you can use a sharp pair of wire cutters to cut the tubing close to the threaded fittings and just use a socket to get the old ones out. I would highly recommend this approach as it will be the easiest way for you to remove what may be very difficult fittings to remove with a flare nut wrench if they are heavily corroded. A socket will ensure that you get them out cleanly provided you use the right size socket and preferably a 6 point socket.
Then, once you have those fitting removed you can more easily match them up at the auto parts store along with the diameter of the tubing you need.

Also, I would be appling some penetrating spray to the bleeder screws repeatedly while you are doing all this other work and try to loosen them one at a time as well. You will obviously be needing to use them to bleed the system later.

I found the easiest way to bleed my car was to just refill the reservoir with fluid and crack the bleeder screws open and let gravity do the initial bleeding of the brakes for me. Once you get a steady amount of fluid from each bleeder close them up, after having flushed any remaining old fluid if there is any.. Make sure the reservoir doesn't go empty during this process.
Then to finish off the job I did a normal procedure with a person in the car and one outside.
The system is split so that one half of the reservoir feeds the Right Rear and Left front and the other half feeds the Lt Rear and the Rt Front. So bleed the brakes accordingly.
Start at the Right rear and then do the Left front. Move on to the other side of the system and do the Left rear then the Right front. Always start from the rear and move to the front. If you do it this way and use DOT 3 fluid you can be assured of an easy brake bleeding job with no air in the system.
DOT4 and 5 have much more tendency to collect small air bubbles in the lines that make bleeding the brakes of all the air much more difficult. DOT 3 fluid is adequate for our cars, unless you are going to race it and use the brakes hard for prolonged periods of time.
I also try to flush the fluid at least every other year to keep moisture out, as DOT 3 inherently absorbs moisture, and it is very easily done by using the gravity bleed method only.

Good Luck

Agree with Rick on the wrenches - a set of flare nut wrenches in your toolbox is always a good thing to have. I use the polished ones from Sears, very nice for not a lot of $:



For fluid, there's nothing wrong with using DOT 4, in fact you should use it. It replaces DOT 3, having superior performance, and you can mix the two. There is no downside to using DOT 4, it doesn't cost any more, and it will keep your brakes stopping better when hot, and it will last longer.

DOT 5 is the one to avoid. Not for use with ABS brake systems, and it isn't compatible with DOT 3 or DOT 4 fluids.

I just had to do this tonight on my riv. Replaced both front pads and rotors, pushed on the pedal, and bam! Lines blows! The job wasn't that bad, the line that blew was the front DS from the rubber line to the trac unit. Now to fix an irritating screech from the wheel that I can only assume is the new pads.

It appears the line needs replaced from just behind the passenger wheel on the underbody all the way to the rear drivers side rubber hose. I think I'm going to disconnect the rubber hose from the caliper and then the fitting just under the passenger seat as it's in good shape and not rusted. Any objections before I do this?

Also, how imperative are the bends? Are they there for a functional reason or for guiding purposes?

i just installed goodridge stainless lines on my riv,its a 14mm for both stock and goodridge. but by all means buy the set of banjo wrenches save you alot of digging. fi youre talking about the stock hard lines,they have to follow the set bends.otherwise i dont think they would fit?

I'm concerned how well this thing will actually make the bends I need:



Thinking about just purchasing this for $10 instead of renting the above for $8

dont be. this tool has been around for as long as there has been brake lines. be confident young man. begin bending!

Agreed. That tool will bend lines amazingly well. You'll feel like a pro after you've bent a line to fit.

They also make a tool like that that has 3 different radius's for smaller or bigger bends.

I guess I'll give it a try then

Got the line out all the way from the passenger seat underbody area to the drivers rear tire. Gonna do some measuring and see what all I need.

After trying to use a pair of cutters I had, it's obvious that I'll need tube cutters in case I need to cut and make a double flare.

dont use cutters.use a high speed cut off tool.dont mistake the gas lines from the brake lines.kaboom paff bamm.you can buy a splice fitting at your brake shop.so as to not have to replace the WHOLE line. do a little investigating.maybe you can save a few feet of line with a splice.

The whole line needs replacing. Actually, both lines need replaced.

DO NOT by any means use a compression fitting!!!!! If you're going to piece it together, make sure you get the proper unions.

I'm not saying you were planning on it, or that stupid, but I've seen it done.

correct. proper unions along with a flare.should come out tits.