Brake pad rub

Novaz · Post by **Novaz** » Sat Aug 25, 2007 4:04 pm

I just replaced the bearings on my front axles and put all new synthetic grease in the hub it really spins nice and free but as soon as I squeeze the calipers on they no longer spin ,I had heard that Nascar cars use some kind of hold back spring is that possible to do on a street / strip car.
Thanks

af2 · Post by **af2** » Sat Aug 25, 2007 7:34 pm

Novaz wrote:I just replaced the bearings on my front axles and put all new synthetic grease in the hub it really spins nice and free but as soon as I squeeze the calipers on they no longer spin ,I had heard that Nascar cars use some kind of hold back spring is that possible to do on a street / strip car.
Thanks

The residual valve is what you are referring too. The master needs to be dealt with!

MileHighMan · Post by **MileHighMan** » Sun Aug 26, 2007 2:07 pm

af2. Can you explain further? I've replaced the calipers, and master cylinder. I sill have some drag in the front brakes. Thanks. Dan.

Novaz · Post by **Novaz** » Sun Aug 26, 2007 3:54 pm

Searching through a few sites it seems that different residual valves are available ie 2# and 10#
but there is still a possibility of brake drag
would it be impossible to bleed the system without the residual in place as it seems that the valve also helps in keeping some pedal there so that you do not need to pump it I use a power bleeder which gives a rock hard pedal and am wondering if leaving the residual valve out is an option, of course I want to remain safe and be able to stop
.
Thanks

Nwguy · Post by **Nwguy** » Mon Aug 27, 2007 12:46 am

Do not use a residual pressure valve on a disc brake setup! I will try to find the appropriate sources and post them later.

Also what type and year of calipers, some are notorious for sticking.

Novaz · Post by **Novaz** » Mon Aug 27, 2007 1:23 am

Ita a stock 72 Nova ss disc front drum rear on a ford 9"
Thanks

motormonkey · Post by **motormonkey** » Mon Aug 27, 2007 10:23 am

Make sure your combo valve isnt stuck,Check witk test light. It also might be time to service your guide pins. Stock disc brakes will drag a little. Somtimes cleaning and lubing the pins and carrage will help.

Nwguy · Post by **Nwguy** » Wed Aug 29, 2007 1:07 am

With stock GM calipers: disassemble the calipers, scuff the pistons with 400 grit, and reassemble with NEW o-rings, The square type of o-ring.

Old, heat cycled o-rings don't flex. Once the piston is pushed thru, there it stays. With new, flexible o-rings the square cross section grabs the piston, and when fluid pressure is released, the o-ring retracts the piston.

Also proper lube on the caliper pins helps.

af2 · Post by **af2** » Wed Aug 29, 2007 6:21 pm

MileHighMan wrote:af2. Can you explain further? I've replaced the calipers, and master cylinder. I sill have some drag in the front brakes. Thanks. Dan.

Sorry Dan,

I miss read the post.
Nwguy hit the nail on the head with his post!
I thought it was a master for drum brakes that has the residual valve in the master that has to be pulled to run disc brakes.
You will have some drag but still be able to turn the thing.

Don Terrill’s Speed-Talk

Brake pad rub

Brake pad rub

Re: Brake pad rub

Brakes

residual valve

valve

Re: Brakes