well i recently did the C5 corvette brake conversion and along w/ it i installed stainless steel braided brake lines. now while doing this swap i couldn't get the factory rubber line to disconnect from the stock steel line so i just cut it and ran braided line the entire way. just to the front two mind you. now i have gone through and bleed the entire system multiple times to double check even the abs portion and the pedal is STILL very soft. it does get hard when the car is not on but when started it is very very soft. does anyone have any idea what could have caused this. is it possible that the braided lines expand when the fluid is run through them and it causes the pedal to go soft since theres extra room in the line. and if this is the cause would i need to get a new perportioning valve and if so what should i use to flow more??? thank you for any help anyone might have.

 

are u sure u have all air bubbles out?
Did you bleed the back brakes?

"now while doing this swap i couldn't get the factory rubber line to disconnect from the stock steel line so i just cut it and ran braided line the entire way. "

??? you couldnt disconnect this hose? how did u get the braided on attached then??

 

Have you tried bleeding the system at the ABS control module?

 

I tell you what worked for me.....

Teflon Tape. Wrap two or three turns around each of the bleeder screws thread. and then do the same on the ABS unit.

Each time I did the bleeding I had small amounts of air sip into the calipers and the ABS unit past the threads. I knew I had done it wrong cause the pedal was way softer than before.

On the ABS unit I conected the clear hose, routed it up to the hood latch and let it drop into a container... I got in the car and turn the key on... and crancked the car up... It burped lots of air when I did that... I mustve actuaded the pumps when I turned the car on, or something.. whatever it was it took care of busines.


Marvin

 

Replacing hard line with "braided" line is a very bad idea. The reason your pedal is "soft" is because all that flexible line expands slightly under pressure.

The reason the pedal feels "hard" when the engine is off is because you have no vacuum power assist, and the pedal effort to apply the brakes is very high.

Change back to a stock hard line as soon as you can. You do not have a safe braking system now. You don't need more "flow" or a different proportioning valve, you just need to get the hard line back on and use the flexible line for the short distance to the caliper.

Brake line fittings are not meant to be teflon taped. Don't try to reinvent the wheel ...errr..the brakes here; just replace the hard line you removed, preferably before you drive the car.

My $.02

 

Why not?

 

The seal isn't the threads like on pipe fittings. Rather it's the conical seat on the double flared tube or within the fitting. Hydraulic brake pressures ar a lot higher than typical water pressures we encounter using pipe threads.

If you have a leaking bleeder, something is buggered up and needs to be remachined or replaced. There are repair kits.

 

Pieces of the Teflon tape can get into the tubing and cause an obstruction.

 

You have to use a flare nut wrench (forgot the size) in order to seperate the hard line from the factory caliper hose. Did you do this? I remember it was not easy seperating them, had to use a lot of force and leverage. I think I ended up using a "cheater bar" to get more torque on it. I used the factory corvette caliper hoses, as this was recommended by Bob Bishop. Worked out beautiful, great brakes compared to factory!!

 

Dude my bleeders are fine. What I was referrring is... everytime I loosened one up to bleed that caliper... I had to connect that clear hose to the tip of it and then run in the car and pump the brake pedal... a one man bleeding kit per say. I always saw small amounts of air comming up the clear hose I thoght all that air was in the brake lines.. When I was done, my pedal was still spongy. Once I wrapped two turns of teflon tape to the threads only the air stopped coming out and my break feel got much firmer.. thats why I said use it. in actuality I think this should be a two men Job.

for the guy who said the brake line pressure is greater than the water pressure, he is correct except for one minor thing The teflon tape is not exposed to that pressure. its only wrapped on the threads and not wrapped up at the tip of the bleeder screw where the seal is achieved.

I agree with the guy who said pieces may block the brake line pipes.. teflon is such a thin tape I can see it melting too however you just have to remember is the bleeder screw thats doing the work there anyway. Now I have done this trick all my life and I never had the brakes nor fail nor brake lines get blocked with teflon tape either. Heck buy new bleeder screws with brand new threads if you think I am suggesting something dangerous.

What I say is that it worked for me.

Marvin

 

I had the same problem with my brakes after bleeding them, but after I used a "Mighty Vac" to bleed them the problem went away, it seems just using the pedal to push the air out just wasn't good enough I needed something to "SUCK" the air out.

 

did you change the size of the lines? i agree no tape and go back to steel lines. i did the converson and love it all factory lines chevy doen't want them to fail!

 

I havent seen those Mighty Vac Pumps here in Hawaii. Anyone Know who sells them?

Mighty Vac Pums really sound easier for a one person Job.


Marvin

 

you can get them at "Competitionaccessories.com" for 41.95, I originally got this to bleed the brakes and clutch on my motorcycle, but I also use it to bleed the brakes on my car.