Brake problems - please help

[CC69Rat]

I have a 1969 (68 clip) I'm working on and were having a hard time with the brakes. We have a CPP (9" if it matters) booster and have actually tried two different Master Cylinders and Proportioning valve setups. The first one was a Wilwood Tandem 1.25 bore and adjustable proportioning valve (two outs for the front, one for the back) we started having "the problems" and thought it was more than likely the MC and / or PV and sent it back for a refund. We have since purchased a Corvette type MC from Performance Online, PV kit, bleeder tool etc. It's a nice setup. That's what's on the truck now.

So here's the deal. Both MC were bench bled and seemed to be fine. The little Do Hickey thing (depth correction plug) has been used in both applications. In fact if you take the MC completely off and push the pedal to the floor.. we measured how far the pushrod was coming out. That's exactly the distance it takes to completely depress the MC at full stroke. From precious experience we know.. that plug is absolutely necessary to get that full push of the MC at full stroke of the pedal.

What's going On? - if you try the old conventional way of bleeding the brakes (open / close while your buddy / Pop pushed the pedal) you don't get any fluid at all at the wheels. .. nothing. We bought a fancy bleeder tool for reverse bleeding.. It will push a little bit but then starts leaking around the bleeder valve at the caliper.

So I separated the front brake lines at a coupler and asked Pop to step on the pedal. I get fluid but it just drips out. When he steps on the pedal it just kinda spits fluid. Absolutely no pressure at all.

Again, two master cup and PV kits.. same problem. Ideas ? Any input appreciated. Thanks.

[demian5]

Sounds like you have some exotic brake system here.
Pictures?
Proportioning valve centered?
Discs all the way around?
Is the rod pushing against the MC when its installed and the pedal is released?

Sounds like you have a few issues.
- leaking around the bleeder valve at the caliper
- I get fluid but it just drips out. When he steps on the pedal it just kinda spits fluid. Absolutely no pressure at all

[Grumpy old man]

What condition are your lines and hoses in ?

[CC69Rat]

All lines are new, all hand bent (meticulously ) and 4 wheel disc all around. Mcgaughys - I think they're 96 Corvette Grand Sport on the back, SS Impala on the front or vise versa.

The whole truck is pretty much new. 73-87 front Kmember swap - frame rail and out to the front wheels.

When you push the pedal it just kinda spits fluid. When I puilled the front brake line apart at one of the couplers it just dripped out when he pushed the pedal. It's like it just doesn't have any pressure behind it for some reason.

[Don Quixote]

It sounds like the master may have to be removed and bench bled.

[CC69Rat]

Pops got it figured out last night. On this PV there is a small brass plug that looks (to me) like you can run one front line out to a Tee, or you could run two lines separately (?) Or one line in either port.. either way there was a plug in it that shipped with the PV / MC kit. This little plug was apparently lose and allowing pressure to slip by. He tightened this plug and..

He also noticed the clevis pin for the brake pedal was making contact with the steering wheel tube (Ididit tilt) and where we thought was the bottom of the pedal wasn't really the bottom. That pin was stopping it. Pop turned the pin around and viola! We have brakes now. All 4, bled and ready to go.

Thanks for your help guys.

Here's that plug..