Brake issues

[Cheapsunglasses]

Don't get a chevy just yet!

I’m just going to eliminate the vacuum booster, and overly simplify everything

 

[RemCharger]

If you take the line off the Mc, does it dribble out?
If no, back off the master from booster.
All you'll Change with booster removal is rod to cylinder relationship

 

[1STMP]

I was thinking residual check valve in the master and/or possibly having the m/c mixed up on routing. Disc doesn't require the rcv but drum does. Greg found out awhile back that he had the ports mixed up on the mc as who was who. When the brakes won't release, if you open the bleeder screw on a caliper when this is happening, does it squirt and then the rotor spins? Different matter but awhile back I had to replace the mc on the wagon as it was leaking out the back. It's a Doc Diff conversion pack so I emailed him to find out application. Never got a reply back so I winged it. 75- F-body[ aspen/volare] disc unit. 1 1/32". Got one from the Rock, no leaky now. And I did adjust the rod in the booster out.

"Disc doesn't require the rcv but drum does."
Not to be contrary here, but
all that rcv does is hold a
a constant (not cumulative)
pressure to minimize pad
travel to engagement of the
disc. Over 5 lbs causes
problems. I run 2lb rcv's
on the front. No problems,
on a 4 disc system.
I lean towards the pistons
in the OP's calipers are not
clearanced properly, or
the pins are not lubricated
allowing them to not slide
as they should.
There could also be a
problem with the master
on the front circuit.

 

[Mackman]

I installed a disc brake conversion and was trying different things because I was unhappy with the braking. One thing I did was install a different proportioning/ distribution valve. After I put that valve in the system, the brakes would lock up when applied and would release after a bit. Went back to the valve supplied with the kit and the lock-up went away. Maybe your valve?

 

[Geoff 2]

Haven't read the complete thread, but the Res Pres valve can be hard to find on some m/cyls [ if installed ]. It can be behind the brass ferrule where the brake line goes into the M/c. Remove brake line, poke some wire in; if does not all the way to the bore, it has a RP valve. Use a self tapping screw to remove the ferrule. The RPV is a rubber plug + spring [ remove both].

 

[ckessel]

I'm wondering if during the manufacturing of the master that maybe they slipped in an RPV where one is not supposed to be.

 

[Krooser]

He’s got stainless braided front flex lines, so I’m pretty sure it’s not the lines. The OP bought a rebuild kit for the calipers and he sent me a pic, nothing wrong with the piston. Waiting to see what the passenger looks like. I mention to the OP that he should turn the air down to 5psi and blow the front lines out to make sure there’s no obstruction.

Just because it's new does not mean it's good...

 

[5.7 hemi]

Calipers were bad, rebuild kit didn’t fit and he got rid of the adjustable proportioning valve. I think that was the problem.

 

[Cheapsunglasses]

I switched manual brakes, redid almost everything and no longer have issues. Case closed, car stops, thanks for the replies everyone