Brake bleeding problems, needs this fixed asap

[protour_chevelle]

Hey guys, I really need some help(yes this is like my 4th thread on it)

I replaced my mastercylinder. Installed line lock and new lines. Couldn't bleed the brakes well at all. The rears would bleed fine and pump up very firm until I bled the fronts and the pedal would go to nothing.

I pulled the line lock out thinking that was it, but the fronts still do not pump up(the rears do but loose the pressure once one pedal travel happens bleeding the front right)

Any ideas guys? I really am getting frustrated with this.

If it matters. 78 Corvette mastercylinder, baer proportioing valve, baer single piston rears, 4 piston fronts.

Heres a couple pics of my setup. front line on mastercylinder is front, which is also the front on the block on the frame.(front= smaller line)

https://static1.pt-content.com/images/pt/2007/05/IMG_3880-1.jpg
https://static1.pt-content.com/images/pt/2007/05/IMG_3881-1.jpg

[BRIAN]

Did you bench bleed master? Try it again on the car. That front block isolates front and rear correct? It is just a block and doesn't effect proprtioning?

Go to Home Depot and get some pipe plugs. Plug the master after you bleed and verify pedal stays hard. If both are good try bleeding again. Hit the calipers with a wrench as you open it, this gets the air to the top. You would be surprised how much can be in there.


Buy a Motive bleeder works incredible for the buck

Good luck

[LowBuckX]

I love my russel speed bleeders on the front. They didnt work well on the rear but on the front they worked great.

2 problems I see. A this loop is a high point where air can hold up in. eliminate this high point. and B this kink isnt helping any. (pic makes it look like a kink may not be)
https://static1.pt-content.com/images/noimg.gif

[paul67]

It could be due to the fronts being 4 pots the master cyl is not moving enough oil into the front pistons before the pedal hit the end of the stroke.

[andrewb70]

Any luck Matt? The loop in the drivers front line is definitely a problem. I would also double check for leaks.

Andrew

[JEFFTATE]

Are you getting a lot of air from the front brakes ?

I had a problem getting all the air out of my front brakes .
( It was just routine bleeding ) I was using a vacuum style bleeder with a clear vinyl hose.
Anyway I kept getting air into the vinyl hose from around where the bleeder screws screw into the calipers.
I removed them ,I put some pipe thread sealer on them and reinstalled them.
Then I quit getting air into the vinyl hose and I managed to get the air out if the system.
The vacuum bleeder would rather suck the air from around the bleeders than through the system.
This may not be your problem but maybe it's applicable.

[protour_chevelle]

The loop there is a problem yes, However it beld perfectly fine with the old brakes with that loop?

Its not a kink but I will change that out. I tried again last night with no luck.

Bench bled the master outside of the car. I put a plug in the front port on the MS and I got a very firm pedal. Took it out and nothing. The MAstercylinder is brand new, not reman. Paid a decent buck for it.

[BRIAN]

Try the pressure bleeder it is cheap investment. Also try as I stated opening the bleeder and hit caliper with wrench you will dislodge stubborn bubbles. Do you know what bore the master is? I think the Vette AM comes in 1 1/8 and 1".

[protour_chevelle]

I think its a 1". I just bought a vaccum pump brake bleeder. I will try it tomorrow and report back.

[JEFFTATE]

The little cheap Mighty Vac bleeder works pretty good.
It's just a vacuum pump with a bottle attached to the bottom of it.

[protour_chevelle]

went to try the vaccum bleeder I bought tonight and i doesn't make any vaccum. Gonna return it tomorrow and borrow a guys that I was talking to tonight. Man this is getting brutal. It was once soo easy!

[protour_chevelle]

My brake pedal also returns pretty slow without the engine on, but I think thats due to not enough pedal pressure?

[68nate]

TRY THIS- get two buddies, one running the brake pedal, one at the right front wheel. YOU start at the right rear and open the bleeder- at the same time your buddy at right front opens bleeder while third buddy slowly pushes the pedal to the floor and holds. You both close bleeders and repeat a few times. Next YOU go to right rear and your buddy bleeds right front simultaneously. Then YOU bleed left front while your buddy bleeds right front simultaneously. MAKE SURE YOU BLEED BOTH SIDES OF THE 4 PISTON CALIPERS- TOP BLEEDERS ONLY
I had to do this on my 68 firebird with stock master and drum/drum proportioning valve with wilwood 4 pistons on all 4 corners. Not quite sure why, but pedal was solid and brakes worked perfect. I've also had to do this at work on some vehicles with a diagonal setup.

DO NOT PUMP THE PEDAL- this can draw air into the system compounding the problem-slow stroke down, slow stroke up, wait 5 to 10 seconds and repeat. Hope this works for you

[protour_chevelle]

Ok guys, I called Paul and Hydratech brakes. What he suggested was that just incase any of my bleeders had crap in them. Just yank them out completely and make sure that my mastercylinder is in a full state of release. This way I can gravity bleed the brakes. I yanked the bleeder in the rear, waited for it to drip consistantly, then put it back in. I repeated it on all corners and I now have a brake pedal with constant pressure!

For not even running their product, I couldn't ask for anything better from Paul. My next go about(project), I will purchase from Paul for sure.

Oh yea, I never changed any lines from when I had previous problems(first post in my thread)

[andrewb70]

Thanks for the update. Its nice to have closure! Glad you got everything working. I guess the loop is not really a problem unless it was above the reservoir.

Andrew