brake issue

[ga.spyder]

I took my 76 project car out for the first time after a lot of work and all new tires and wheels.Took a 2 hour ride through some mountain roads.Lots of curves and hard braking.The car ran very well.had a ball!I have an issue under hard (panic stop) braking.The right rear locks up.It did this before I rebuilt the brakes ,also.All new pads,hoses,and front calipers.I did not rebuild or replace the rears.Everything was removed,cleaned,greased,etc...Any thoughts?I am wondering if I might need to remove or replace the compensator.The calipers seem fine,even under hard repeated braking.Only does it when I do an emergency stop.Being a budget build,I dont want to throw parts at it.
Craig

[So Cal Mark]

does the front end dive drastically when you panic stop?

[ga.spyder]

Hey Mark,
It does dive a bit,but I wouldnt call it drastic(not a lot more than the 82).Stops are fairly smooth with no pull.Under normal to aggresive braking it is fine.But every panic stop ,the right rear locks and skids...weird.
Craig

[rlux4]

When I did the panic stop on last year's Oregon trip that first started the brake fluid leak it was also on the right rear. Coincedence? I don't know, but what caused it is the piston going past the normal range at the seal. This new "uncharted territory" was dry and caused damage to the seal which eventually became a leak so bad it dripped onto the wheel and got flung up on the body and stripped the paint.
Point being, that brake was locking up also until I rebuilt it.
Ron

[ga.spyder]

I just had that caliper apart..nothing obvious.This car has been sitting up for a long time,so maybe it does need a rebuild.I was hoping it had something to do w/ the compensator.It did this before I did this most recent brake work,but it had a bad pull to the right which felt like the front.Pull is completely gone,just this lockup on panic stops.Car really runs good,this seems to be my only issue!!

[rlux4]

I envy you.
I wish my life only had one issue.
Ron

[baltobernie]

just this lockup on panic stops. Car really runs good,this seems to be my only issue!!

Craig, you've heard of GoDaddy?
Well, your right rear is your WhoaDaddy! When she starts talkin', you best start listenin'

[pooldoctorstl]

Just my opinion, but I think you might have 2 problems. One with the compensator and one with the LEFT caliper. 1) The compensator probably isn't working and isn't regulating fluid flow to the calipers when the rear end goes up in a panic stop, so the right is locking up. 2) The left caliper might be frozen and not working, so it isn't doing much of anything and doesn't lock up like the right does. If it was working, it would probably be locking up too. Pulling issues are more pronounced with front brake problems than rear, so the fact that it isn't pulling doesn't mean there isn't a caliper problem in the back. Also make sure the hoses are clear and have good flow through them. Rebuild kits are cheap (like 7 bucks for the kit that does both calipers) if you can tear them down yourself, so your budget won't be blown.

Jeff

[ga.spyder]

Thanks guys,the compensator is such a PITA that I think I might eliminate it all together.Mark sells a bypass that is about the same price as a new one.The rear hoses are both new,and I checked both calipers for operation before and after the brake work.I know that doesnt mean they are working at the same strength? I drove the car this morning(before it started snowing ),and the front end does tend to dive under the panic stop braking.What does that mean? I am really happy with the car but I need to get this fixed as the wifey wants to start diving it to work,store,mall.......
Craig

[pooldoctorstl]

The compensator is there to prevent rear lockup in a panic stop, especially in wet road conditions. Eliminating it will not solve this rear lockup problem you have. If the right rear is locking up now, it will do the same if you eliminate it because the compensator is not doing its job. Car manufacturers do everything they can to cut manufacturing costs and if it could have been eliminated, Fiat would have. It is a safety component and is there for a reason. Think about your wife losing control at 50 mph in a hard stop because some idiot slammed their brakes in front of her. Clean it up, lube the bushings and adjust it and it won't be a problem. Look at it this way...if you don't like your wife, eliminate the compensator.

[kmead]

I would try adjusting the compensator, it is intended to prevent what you are experiencing. Removing the compensator will not remove this problem. The Haynes manual has a very clear adjustment procedure which is not difficult to perform.

If you do remove it, which I don't suggest, at least go with a rear pressure limiting valve which can be adjusted to the correct pressure (just short of incipient lockup) which requires testing to get it right.

http://www.chevyhiperformance.com/techa ... index.html

http://www.speedwaymotors.com/Compact-A ... GoogleBase

http://www.jegs.com/i/JEGS/555/63020/10002/-1?CT=999

[ga.spyder]

Thanks Jeff and Karl.I agree that removing the compensator doesnt help the issue I am having.I think the problem lies in one of the calipers(left?).I got under the car and cleaned and visually inspected the rear system.It appears that the compensator and the hose have been replaced at one time by a p/o.They are much newer looking than the rest of the hardware.I will look into the adjustment,if that fails I will have to work on the calipers.Being a low buck rebuild,I hesitate to drop a lot into it.Brakes,however aint the place to pinch pennies!
Craig

[baltobernie]

You put 200 lbs. in the right seat, and I betcha both rears lock at the same time.

[ga.spyder]

hmmmmmmmmm...good point Bernie.I hadnt thought of that.I will recruit a passenger and take it for a spin.Have you dug out from the latest snowstorm yet? Been a brutal winter for you.
Craig

[So Cal Mark]

if the front end is diving, the rear end is unloaded and will lock up quite easily. How are the shocks?