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96 PA with rusted brake lines


688i
09-20-2012, 09:55 AM
I had a brake line blow out due to rust and had the shop fix it due to time and it needed it's annual state safety inspection. There are three other brake lines in the same area going to the ABS Modulator/Valve that are severely rusted for about a 6 inch long area on each one. The shop said it would cost several hundred dollars to fix the other three lines because of their connection location to the ABS M/V, it would have to be removed from the vehicle so the entire lines could be replaced. I can fairly easily fix them without removing the ABS M/V if I just cut out the damaged area and use compression fittings to splice in three new short pieces of tubing. However after doing a little research on the net I see that as a general rule compression fittings are not legal to use on brake lines because they could blow out under an emergency braking situation. My question is can the proper steel and pressure rated compression fittings be used to legally and safely splice brake lines. I know from my profession that these type of fittings can be obtained from companies like Swagelok and Gyrolock that are rated and used on systems that experience from 3K to 15K pound system pressures. I'm thinking that some idjuts have tried to use brass low pressure tubing fittings on brake lines and they have not held up to hard braking pressures. I understand a hard braking situation could cause pressure spikes as much as 1K pounds or more. Please advise.

Tech II
09-20-2012, 11:10 AM
What you need is a bubble flare tool, fittings and unions......don't have to remove the BPMV......

You will have to cut the lines where you have enough access room to install the bubble flare tool(remembering to put the fitting on before you make the bubble flare).....then the part you cut out can be easily replicated with a tubing bender or I just use a piece of pipe in a vice, and make bends in the new line, using the old line next to it as a template......

autojoe
09-21-2012, 07:50 AM
they make a flexible brake line that is easier to flare and bend without a bender tool.....i bought at autozone.....dont use compression union.buy flare union.i had problems with a bubble flare leaking when put into the flare union i bought at autozone.they probably make flare unions with a seat for double flare and bubble flare.there is also 4 or 5 sizes of bubble flares.the flares that are in the abs modulator are bubble flares.i would cut off somewhere down line and install flare unions and double flare should work with them.sometimes you have to tighten a little if a few drops are noticed on fitting.the flexible line is nice to work with and to flare.little pricey.i replaced all mine from abs modulator back....i bought short section of prefabbed brake line with bubble flare and cut other end and bought flexible line and installed a flare union and doubled flared and installed together.i live in pa also.

Tech II
09-21-2012, 07:58 PM
Have never seen 4-5 sizes of bubble flares.....their size is determined by the outer diameter of the brake line........

GM has a great bubble flare tool that also makes double flares.....and it's hydraulic, making it easy to use......comes with various dies for different size brake lines.....

autojoe
09-21-2012, 10:01 PM
my bubble flare kit has 4.75 mm (3/16"), 6 mm, 8 mm or 10 mm ,also have a standard flaring tool.not too many people are going to buy the new hydraulic tool they are very pricey with all dies.....for the average person they would not use much and better off using double flare tool.

688i
09-26-2012, 02:55 PM
I have a bubble flare tool and have used it several times on my truck where there was room to do it. There is no room to do this where the rust areas are on these four short sections of tubing. Also I have had problems with weepage when making flare connections anywhere other than on a work bench which won't work for this application. I'm sure the hydraulic tool recommended is way too expensive for this one repair. I appreciate everyones feedback but none of it is much value to my situation. If I can't use compression fittings then I will have to pull the ABS modulator and replace all four tubing run sections. Again does anyone know of where I might purchase a 3/16 DOT approved brake line compression fitting?

Tech II
09-27-2012, 08:05 PM
You can buy different lengths of of brake lines, with bubble flares(sometimes called "European").......you make a cut with a tubing cutter, based on the length of the line you buy.....

For example, say you buy a 2 foot length....Using a 2 foot long string, follow the bends from BPMV, to find where to make the cut.....once cut, you now take the bad line and use it as a template to bend your 2 foot line....you can bend the remaining line in the car, in any direction to make it easy to make a bubble flare.......then bend it back, add the union, and your first line is done.....

This way the BPMV can stay in place....

durangoman
09-28-2012, 09:35 AM
I have a 98 pa ultra I am parting out if you need any lines.

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