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brake line and portioning valve question

A

ad356

New member
i am working on my 2000 grand prix gtp. i had to replace the driver side brake line about 1/2 way down the car through the portioning valve and back to rubber hose. i replaced the line on both sides of the portioning valve, i had no choice it was rotted badly. i used a standard flaring tool. i tightened it down really good but it still leaks bad. i dont think GM used a standard flare inside the portioning valve. how do i fix this thing? can i buy a special tool to make the proper shape of the flare? i had to re-use the old fitting because the new fittings i had that i was using everywhere else were not same size as what was on the portioning valve.
 


I redid my entire brake system, from what I remember I did everything in a double flare except the hard line to flex that goes to the caliper, I did a bubble there. If it leaks your A. wrong flare B. Not complete flare C. Pits in sealing surface/rust D. Not tight enough. I reused both of mine and not one drop of fluid. The correct fitting must also be used (reusing old isnt a good idea)

chss by Corey S, on Flickr
 
what is the correct fitting? i know its not the same as the other fittings. when i bought line i bought a coil if it, make and bend my own lines not buy the straight lengths they sell. as far as the line itself i am only replacing it up to where the line is solid again. the car isnt really rotted but it will be after a few more winters. winters around here are aweful. the car runs and drives fairly well so i just want to keep it going for a few more year. my summer vehicle is a 1996 camaro Z28 and i gotta have something to drive in the winter. hence i really dont want to spend too much time or money on the grand prix. i like these cars but if the vehicle is rotted or starting to get rotted i wont spend too much time or effort on it. in this climate rusted out junk is everywhere and its barely worth fixing. if it was a super clean example sure i would spend all the time and money and replace the entire line the whole length. in the future i might buy another GTP but a cream puff, and part out my current car.
 
at any rate thanks for the info i think i used the wrong type of flare. i usually dont replace brakes lines and try to get rid of a car before they go bad, if the brake lines are shot typically the rest of the car is also starting to get rotted
 
alot of newer cars are bubble flare, faster production as you basically skip the second step of a true 45" double flare.

basically you can use the std "flare kits" but just do the first step, and burnish the fitting upon installation/prior to installation, i.e. tighten/loosen/tighten/loosen/tighten to make sure of a good seal and final forming to the oem junk.

always forgo brass hardware for steel , brass is really too soft but it does conform well if your stuck with a particularly ****ty rental tool like i see at most places nowadays. tis a damn shame.

make sure you ask for anything behind the counter....find your old timey shops (old carquests/napa's etc...and youll likely find drawers full of all the nifty fittings you could ever need.
 


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