colojeepguy
Colorado Springs
Yes
R&P GM 1/4 Ton Disc Conversion
- Thread starter FinoCJ
- Start date
Well...got one side completed....it's been a bit of a fight but hopefully it will all work when finalized. Knuckle studded, new drag link and TREs, new seal, new kingpin bearings, new wheel studs to work with the disc brakes, etc. I will wait to bleed until the other side is done...the driver side should hopefully go a bit easier now that I sorta know what I am trying to do. Then will have to remove the drum RPV from the MC (assuming it has one) for the front circuit.
RPV = residual pressure valve
Usually a drum brake circuit will use a 10lbs RPV whereas a disc brake circuit would use no RPV or possibly a 2lbs one. When I bought the Wildwood MC from R&P, I ordered it as drum/drum, so I would expect it to have 10lbs RPV for both circuits. Rich said I would remove if I converted a circuit to disc.
Usually a drum brake circuit will use a 10lbs RPV whereas a disc brake circuit would use no RPV or possibly a 2lbs one. When I bought the Wildwood MC from R&P, I ordered it as drum/drum, so I would expect it to have 10lbs RPV for both circuits. Rich said I would remove if I converted a circuit to disc.
So I am not sure about the RPV....I assume it would be the larger hex head between the MC and the brake line flare nut. Basically what the flare nut is threading into.....
As this is a Wildwood MC, I searched for Wildwood RPV to see what it looks like.... if there are rpv's in the MC, they sure don't look like this.
https://www.wilwood.com/MasterCylinders/MasterCylinderValves
So, I am kind of thinking the RPVs got left out? (The pedal has never felt great with this setup)....so guess I'll try bleeding the system and see what happens. If there is a 10lbs RPV, once the pedal is pressed and caliper piston pushes the pads against the rotor, they shouldn't release even when pedal is released?
As this is a Wildwood MC, I searched for Wildwood RPV to see what it looks like.... if there are rpv's in the MC, they sure don't look like this.
https://www.wilwood.com/MasterCylinders/MasterCylinderValves
So, I am kind of thinking the RPVs got left out? (The pedal has never felt great with this setup)....so guess I'll try bleeding the system and see what happens. If there is a 10lbs RPV, once the pedal is pressed and caliper piston pushes the pads against the rotor, they shouldn't release even when pedal is released?
The residual valves are surprisingly simple. Look for a rubber disk with a hole in the middle or a small spring assembly that allows a free flow out and a slight resistance in.
I guess it is under the large hex. Remove anything under the large hex that does not actually seal the hex to the housing on the circuit going to the disks (or pull both and use the disks from the local ad)
i think you just solved how I'm gonna hook up a hydraulic tow bar brake line...
I guess it is under the large hex. Remove anything under the large hex that does not actually seal the hex to the housing on the circuit going to the disks (or pull both and use the disks from the local ad)
i think you just solved how I'm gonna hook up a hydraulic tow bar brake line...
Yep figure one in the pdf needs to be removed.
Then the inline valve is basically the lighter resistance duckbill in a housing.
thanks - that first pdf has the info
Too bad they can't furnish you with the 2lb duckbill and avoid the extra plumbing.
I guess since I am using a frame mount at about the same height at the caliper, I should use a 2lbs RPV.....may not be critical. I can call Willwood and see what they might have.....
It's 2lb for disk. 10lb will drag and no valve will take a bit of pumping to work. I had one wilwood brand in-line valves fail so if you can just replace the guts that's the way to go.
If you go with the in-line valve keep it away from the exhaust or the internal rubber duckbill may get upset.
If you go with the in-line valve keep it away from the exhaust or the internal rubber duckbill may get upset.
I would check for both valves being in there. You could jack up one side now and see if the brakes drag. Like Joe said, do you need to pump the
brakes to get any action? You could also have someone hold the brakes and check to see if the wheel turns.