Need advice on front disc brakes

[donsrods]

While my Son's transmission and motor are out of his T (tranny had to go back to TCI because the pump failed after 200 miles :sad we are going to do some of the little tasks we have been putting off. He and I are getting together tonight to do them.

One thing we need to correct is the front disc brakes seem to be not retracting. At first we had GM brakes, but now have Wilwoods, and both did the same thing, the pads are dragging badly.

We have a 2 pound residual valve in the front and have heard that some master cylinders have a built in residual valve in the outlet, so we might be doubling up. It is a master cylinder we got from Total Performance. We intend on looking at it to see if there is one up in there, what do we look for? How do we remove it if there is one in there?

Any suggestions would be appreciated. I have never used discs before, just drums.

Don

 

[old round fart]

I wouldn't think you would want any residual pressure on disk brakes. I thought residual valves were to make drums work better with disk brakes by keeping the shoes a little closer to the drums with no pressure from master cylinder so they would engage at the same time.

 

[Youngster]

Maybe a call to Brian would be in order. He should be able to tell you if there is a in unit valve.

Ron

 

[donsrods]

No ORF, I think you are talking about proportioning valves. I get the two mixed up too. The residual valves are generally a 2 pound for the front discs and 10 pound for the rear drums, and are used to keep fluid from draining back to the master cylinder if it is mounted lower than the wheel cylinders.

We are going to poke around tonight and see what we can find. It is too late to call TP, but I might tomorrow if I can't fix it tonight.

Don

 

[Rick]

While my Son's transmission and motor are out of his T (tranny had to go back to TCI because the pump failed after 200 miles :sad we are going to do some of the little tasks we have been putting off. He and I are getting together tonight to do them.

One thing we need to correct is the front disc brakes seem to be not retracting. At first we had GM brakes, but now have Wilwoods, and both did the same thing, the pads are dragging badly.

We have a 2 pound residual valve in the front and have heard that some master cylinders have a built in residual valve in the outlet, so we might be doubling up. It is a master cylinder we got from Total Performance. We intend on looking at it to see if there is one up in there, what do we look for? How do we remove it if there is one in there?

Any suggestions would be appreciated. I have never used discs before, just drums.

Don

Yes Don there is a check rubber thingie in the master cyl.and yes it has to go.Brian can tell you about the drill and tap stuff i don't wanna mess it up.
2 My Wildwoods also drag the reason is the calipers have no spring return and rely on preasure release to back off the rotors.Which sucks.The residual valves are intended to twart the migration of brake fluid from the wheels to the master cylinder of cars with the master cyl mounted below the floor.If you have 3/16 brake lines you will need a proprtioning valve near the rear end to even out the preasure NOW if you use a combonation of 3/16 and 1/4 inch lines you can get rid of the proportioning valve. Now back to your post.The residual valves wont let the pads back off far enough to NOT rub all the time and squeak.So i eliminated mine and Thomas's by taking the screw out of the side and taking a drift punch i poked the valve right out.I cant afford to run that much stainless again for a replacement line so the residual is just an extention of my lines.Hope this helps yall.(my fingers are sore from typing)

 

[tfeverfred]

When I first installed the claipers onto my brake set up, it was easy to see that they would rub. Lucky for me, I had purchased the spacers that Total sells, that go bwtween the caliper halfs. Set my pads just right.

Also, in a conversation with Brian or Pete, he said that some guys just grind a little of the pads off, to a point where they don't rub. Made sence, but I'm glad I didn't have to do that.

 

[donsrods]

Rick, we did exactly what you did tonight. We removed the guts from the front residual valve and the wheels now spin free. We tried spinning them before we did anything and there was a lot of drag, then after we took the insides out they now spin free. His m/c is pretty high in relation to the wheel cylinders, so he should be ok.

Fred, we don't have to grind any off, them dragging for about a 5 mile ride did that for us. :lol: Also put little grooves in the rotors, but not bad. Now I see why I have stuck with drums all these years. :lol:

Thanks for all the advice guys, I appreciate it.

Don

 

[Todd]

I had a similar problem on the Model A Tub.
What turned out to be my problem was the weight of the pedal. It put just enough pressure on to drag the pads when warm. A spring mounted to take the pressure of the master fixed it.
Hope this helps someone.

 

[ACJC]

Spacers for the caliper halves Fred? I have to check the catalog and explore that remedy as apposed to shaving the pads.

My front Wildwoods drag too and squeel.

Man, I love this site, I learn something new every day.

 

[Rick]

Spacers for the caliper halves Fred? I have to check the catalog and explore that remedy as apposed to shaving the pads.

My front Wildwoods drag too and squeel.

Man, I love this site, I learn something new every day.

Do you have the TP set up?The reason i ask is i had to take mine to work and grind .060 off the spacers.

 

[ACJC]

Sure is. I'm not sure of where the spacers are. I look closer Sat. while I have tires off for balancing.

 

[LumenAl]

Sure is. I'm not sure of where the spacers are. I look closer Sat. while I have tires off for balancing.

The spacers they are referring to are specially made for a wire wheel setup from Total Performance... they look like this:

although some folks like myself fun these polished SS rotors instead:

They use these calipers:

and to get the right float, on some setups you need to use these spacers that fit between the two sides to back the pads off the disk just a hair...

That help ya out at all?

 

[ACJC]

Nope, mine are single piston Wildwoods. Some times they drag and sometimes they don't. But they are dong a heck of lot more work thane the rears. I am looking into the 2 psi (Disk) and 10 psi (rear drum) check valves.

 

[Rick]

The spacers i was talking about go behind the mounting bracket that bolts to the spindle.I did mine a year ago.I talked to Rich Fri.at T.P. and he said yep you have to grind the spacers to fit the caliper over the rotor properly then the aluminum spacers between the caliper halves come in 1/4-1/8 increments to open the area between the pads.All this is based on Ford spindles.