Discussion Forum - Northstar Chevelle Club

bwild70ss396 · Active Member

Brake bleeding issues, looking for suggestions

Chris R · 2K+ Club

Brad, do you have any sort of solid pedal now that the front brakes are bled or does it just go to the floor?

SShink · 3K+ Club

I have a similar problem on the vert after I installed a disc brake conversion kit. Lots of front brake fluid on bleeding, but little to nothing to the rears. I called the company that made the kit, and they said the first thing to try is to loosen the booster at the firewall, and try to bleed the rears. They said there could be pre-load on the master cylinder plunger from the brake pedal shaft, and that can cause the orifices for the rears to get blocked and not bleed. They said if that didn't fix it, to call them back to talk about a new prop valve.

I haven't tried it yet since the car stops on a dime even without the rears being fully functional. It's on my winter list of things to do...

Lost in the 60s · President

Just as a system trace, I would loosen the brake line at the prop valve inlet and see if you have fluid there and then when you do, loosen the line on the outlet side until you get fluid out of it. I would think having the valve wide open to allow as much flow as possible would aid purging the air thru it. I know, that's messy and gets fluid on painted surfaces, so it's just a suggestion.

bwild70ss396 · Active Member

The Pedal has a firmer feel, but still goes to floor, I did adjust and re drill the hole in the brake for the proper ratio. The rod is in the starting position all the way back. I can get at it under the dash to make those kind of adjustments and see the back of the booster. I run silicone fluid in my rebuild cars. Not as hard on painted stuff. I will try messing with the proportioning valve and maybe switch that out if there is lack of fluid on exit side . I keep thinking thats where I need to focus.

-- Edited by bwild70ss396 on Saturday 19th of October 2013 04:06:18 PM

67ss · 1K+ Club

brake gauge.jpg

Kind of funny this came up I just bought this brake pressure gauge kit a week or so ago.

I would also check all the lines you flared to make sure some flashing is not stuck in the line blocking the fluid.

dashboard · 2K+ Club

Nice looking setup you have there.
Is it possible the brake system incorporates some form of brake fuse? On some systems with a fuse the fuse will set when doing the rear brakes because of high fluid flow (during bleeding) and must be reset or overridden during bleeding.

Just a thought.

bwild70ss396 · Active Member

I am still having issues with this brake system. I bought A new master cylinder to try that, but did not help. I have fluid at the calipers when I bleed the system. I have the cadillac rear calipers. I have the e brake I think adjusted correctly? The pedal still goes to floor. I can hear a what sounds to be a vibrating valve noise coming either from the master cylinder or prop valve. Should i have a residual valve??? I have never had a system give me this much grief. Anybody have a pressure bleeder???? There is no electricity involved in my old school system. Any ideas or if someone has some time to play give me a call

Brad
763-486-6518

Lost in the 60s · President

If the prop valve doesn't have any residuals built in, you may need one for at least the rears to prevent the fluid from back flowing out of the caliper.