Front Calipers stuck

[ChrisK]

Took the car out today to run it up to near highway speed. Ran great and stopped good. Too good.
the fronts were stuck. First time I had this problem. I have front discs(metric Chevy luv style) and the rears are Chevy 10 bolt generic drums. I have a 10lb residual valve on the back and a proportional valve and 2lb on the front. 1" bore vette Master Cyl. The RPV's appear to be installed correctly. Barring an incorrect or malfunctioning RPV I'm looking at the Master Cylinder travel possibly being held up by the rear proportioning valve which was wide open. Anybody else had anything similar?

 

[choppedtop]

Possible that there is not enough play on push rod? Front residual valve not releasing. Did you break the bleeder on the calipers to release them? Were both fronts stuck or just one? Let us know what you find.

 

[Spanky]

Anybody else had anything similar?

I have the same setup (10-bolt rear drums/metric calipers) but no residual valves on mine. Not identical, but in my case, the calipers were dragging because the brake pedal was not returning all the way. I had a clearance issue that, once resolved, cured the problem.

 

[ChrisK]

Both were stuck. I let it cool and there released. I'm going to look at the pushrod. I messed with the pushrod a few weeks ago. I will start there.

 

[ChrisK]

Its the pushrod. I think the geometry isn't right. I shortened it some more and will go from there. I might have to fabricate a new one.

 

[fletcherson]

Its the pushrod. I think the geometry isn't right. I shortened it some more and will go from there. I might have to fabricate a new one.

That’s why they are called projects...

 

[AusBucket]

G'Day Chris,
Have you got a return spring on your pedal, I've had a M/Cyl piston not return fully because the weight of the pedal was stopping it. After I put a return spring on it, it worked as it should.
Regards,

 

[ChrisK]

The spring is a great Idea. I might have to do that. The pushrod was creating an over-center type condition that wouldn’t let it return fully. Also while down underneath the car I noticed the pressure brake light switch was a little wet with brake fluid. I have it on the rear circuit. I think I will plug it and wire a chevy switch off the brake pedal.

 

[fletcherson]

The spring is a great Idea. I might have to do that. The pushrod was creating an over-center type condition that wouldn’t let it return fully. Also while down underneath the car I noticed the pressure brake light switch was a little wet with brake fluid. I have it on the rear circuit. I think I will plug it and wire a chevy switch off the brake pedal.

I have read others complaining about the pressure switches too.

 

[AusBucket]

Too much crap made in China now, very poor quality control!

 

[Spanky]

I have read others complaining about the pressure switches too.

This is what I used, and it seems to be working great!