Right Frt Brake Lock Up

[timc]

My right frt locks up on dry, and very scary in wet. I have:

1) Flushed Brake Fluid
2) Removed frt pads and exercised the caliper psitons, appear to be very smooth.
3) Replaced pads and rotors.
4) Replaced all rubber brake lines with SS.

Can this be due to car not being corner balanced? Possibly to much/little weight on right frt????

[equality72521]

Has this just started? If not, I would say corner balance.

[IMR-Merlin]

Stupid question but have you performed all of this work on all 4 corners or just the one giving you trouble?

[IMR-Merlin]

Also, how does the peddle feel? Hard? soft? Does the car pull to one side under moderate braking?

[timc]

Performed work on all four corners. Pedal feels normal. Being going on for a long time. I can't remember when it started, may have been when I raised the frt of the car years ago as it was a bit to low, I just cannot be sure that was the cause...

I guess my question is, can uneven weight on the frt cause this? and should I apply more or less weight to that corner to correct???

[Flieger]

Yes, I had that happen consistently. It was corner balance being very off.

[IMR-Merlin]

I vote the same as Flieger.

[timc]

thx, that's kind of what I have been thinking. I'll get it balanced...

Tim

[equality72521]

Originally Posted by timc

Performed work on all four corners. Pedal feels normal. Being going on for a long time. I can't remember when it started, may have been when I raised the frt of the car years ago as it was a bit to low, I just cannot be sure that was the cause...

I guess my question is, can uneven weight on the frt cause this? and should I apply more or less weight to that corner to correct???

Yep, corner balance.

[JFairman]

Sounds like there is more weight on the left front and right rear wheels if the right front locks up like you say.

The car may look level if the above is true and it may want to pull lightly to the right when going straight in the middle of the crown in a road like on a 3 or 4 lane divided highway.

Raising the front will cause the front wheels to toe out.

[boostfix]

Hey Tim,
I have the same problem with the front right on my 88. I have so far re-built the calipers, new brake fluid, new rotors (they were out of spec for thickness), new pads. After that, I still have the lock up issue witht the front right. My conclusion was the same as recommended by others.....do a corner balance next. Work life imbalance has made it impossible for me to get CB done yet....so I am interested to hear how you make out with your the corner balance! Good Luck!
Dan

[timc]

MY problem is, I am waiting on the funds to replace torsion bars and shocks, so I really don't want to do a full corner balance right now. What I may do, is add a bit of weight to the RT Frt. When I raised the frt of the car, I tried to do that as evenly as possible, to keep both frt sides level and also to not throw off the weight of the left and right front in the event the car had been previously corner weighted. I apparently failed on keeping the weights even.

[Flieger]

It is not the weight distribution, it is how the springs are set as far as their unstressed positions. Adding weight may not be as effective as you think, unless it is quite a bit.

[timc]

Originally Posted by Flieger

It is not the weight distribution, it is how the springs are set as far as their unstressed positions. Adding weight may not be as effective as you think, unless it is quite a bit.

Assuming 1) what you say is true, and 2) I did not have this problem before I raised the frt of the car, what is my solution, short of a full balance? I would think that I just need to remove some weight from the right front by lowering that corner in very small increments until I no linger have lockup on right front.

[Flieger]

Raise the light corner.

[equality72521]

Flieger is correct. Each corner of your car weighs the same regardless of how much you adjust height. Crank the adjustment bolt on the front right corner up or down and that corner still "weighs" the same. It's about the relational spring tension between the four corners. Reducing spring tension on one corner affects the spring tension on the other corners, especially the opposite corner. This creates the table with short legs effect. The spring tensions are balanced when correct. Reducing spring tension on one or more corners gives the effect of increasing tension on the others. When this happens you have less downward pressure on a specific tire in relation to the others. Since that tire has less downward pressure because of decreased spring tension you have a tire that will lock up sooner than the others.

[timc]

Ok, so the right front locking up, is the light corner, as it does not have adequate spring pressure, so I raise the right corner to increase spring pressure on that corner, which also reduces spring pressures on the other corners?

[equality72521]

In a simple way, yes. But, each corner is affected. Having someone professionally corner balance it is the best approach as each adjustment affects the other wheels. You have to keep adjusting each wheel until you have balanced downward pressure at each wheel.

[Flieger]

If you had some scales of your own it would be nice. Otherwise you just make small adjustments and go out and test drive, repeat until you find what feels good.

[JFairman]

It's easy for you to experiment with it some more.

On a level floor with a floor jack and block of wood jack up the rear by the motor center seam. Then measure the left and right front torsion bar mounts to the ground and the fender arches to the ground.
Turn the front adjusters a quarter or half turn at a time to hopefully get close to level in the front and road test. I think you can get it better than it is now.

Could be a front caliper too.