I have an 86 IROC Z-28, 350TPI,700r-4,
I finially got most of the buggs worked out of the fuel system an brakes,except one BIG problem.
When you hit the brakes it pulls so hard left that w/o the powersteering you will lunge into on coming traffic! ( I found out the hard way this weekend when my PS belt broke on a hard corner an I had godzilla on my hands suddenly)
I have replaced the master cyl(it was bad) all pads an just installed a new left caliper, I went for a test drive an all seemed ok until I was driving home the next day an the problem came back.
Has this happened to anyone?

 

Have you had an alignment done recently? That could be one possible cause. Did the problem develop over time or did it just happen all of a sudden?

 

sounds like the right brake hose is a problem. 1st try bleeding theright caliper and see if that helps.

 

Sound like the brake line to me also. Mine did the same thing, changed out the brake lines and it went away.

 

I will have to try the line replacement today or the next,
I have bleed the system completely,Used a whole LARGE botle of fluid!!!
Figured I would get all the old fluid out.
No I havent had an alignment lately but the car goes very straight when you let go of the wheel,its just when you hit the brakes all hell brakes loose.
Any other ideas??
Also why would the hose cause this,think its damaged inside?

 

Did you do your front brakes or did a shop? Someone may have forgot to clean off the sliding surface that allows the clipers to move freely while applying the brakes. If this is the case, it may cause the brakes to grab harder on one side. And in the long run will ruin the pads, and maybe the rotors too if left to long. Simple to check, take off the tire and caliper and check the two surfaces, if they look all rusty, no one cleaned them off then. I also like to use a "tinny" bit of never seize on the surfaces, this allows then to move freely till your next brake job.


You also say that you replaced the left caliper, and that it pulls hard to the left. hmmmm, Maybe something to do with the new caliper, or the right one is on it way out and the left one just works better. For the price of OEM calipers today, and brake parts in general. When I replace one side, I automaticaly do the same to the other side too. Evens things out if you know what I mean. After all this is your stopping power you are playing with here...Very important!
HTH

 

This is typical for the thirdgens. If you assembled everything correctly it definitely sounds like you need to replace the front brake hoses.

 

the right brake hose?? to replace is that right not the left where the problem is??
Yes I did the work myself,I dont trust anyone else to work on my stuff thats why I became a mechanic.
I practically rebuild everything when I do a service,ie take the calipers apart clean them thoroughly an put them back together,I sand(lightly) the sliders(more like polish)an lightly grease them,same w/ the pads(the parts that make contact to slide.
This is an old racers trick that has worked well for me an I never have any brakes stick.
This crap is puzzleing me though,I will change out both lines an see what happens.

 

I am really begining to think it is the right side caliper that is really causing the problem. You have a bran new one on the left side which may be stronger then the right side???? Lines are probably a bit cheaper, so would be best to try that first. But if you still have a porblem I would look into replacing the right side caliper. Just have to wait and see. Hope you get it figured out.

 

let's see if I can be of any help.

first a word on calipers. typically it is a good practice that what you do to one side of the car you do to another. does not apply to everything but calipers, shocks are thing I would replace in a pair. Only a calapsed hose will cause pulling and is very, very rare. I've done over 500 brake jobs.

Now,

1) with the front wheels on and off the ground, have someone step lightly on the brakes. try to spin the tires. drag should be the same on both sides. release and check that both sides spin freely. Next repeat above pressing down a little harder each time until the break pedal is all the way down. The brakes should release and spin as easy on both sides. If one side sticks, the drag will be noticable when you try spinning the tire.

2)visual inspection: take the wheels off. measure rotor thickness. it should be about .980. If the left side is far below specs, than it will heat up much faster due to lack of material and cause locking. if below, replace rotor. no need to do both sides unless below specs.

3) if rotors are ok, be sure that there is absolutley no grease or oil on the pads and rotors. Use break parts cleaner only to clean and keep all parts free from dirt or grease. grease or oil on rotors or pads will cause that side to slip, thus seemingly grab more from one side.

4) make sure that guide pins are are clean and lubed with the proper brake lube. also make sure the the surface that the pads are gliding on is clean and free from any rough particles. If not use emmory cloth to clean and use molylube to lubricate. *(when using molylube, do not dab it on heavy. use about a pencil tip full to lube the entire lenght of the slide. when done you should almost not be able to tell that you lubed anything. but if you feel it with a clean finger, you can feel the smoothness of the molylube)

5) At this point since you replaced the left side caliper, the only thing you really can't verify is if there is any crud inside the right caliper, however, the first inspection might have revieled some clue to this. I use to rebuild calipers with a new seal and dust boot but for the price now adays, it's easier to just by one that's already rebuilt.

6) if you replaced the master cylinder you should have bench bled it first.

7) put the wheels back on if all above is ok. If so, now check your front end. you can of course do it as step one and maybe save some time. make sure your idler arm, ball joints etc. are within specs. If not, for example a bad ball joint or bushing may in fact cause a pull.

That's start. Remember though no matter how old the car is, if everything is ok, it should always stop evenly with out pulling.

hope that helps.

 

I replaced the right brake hose,Whala!!! No more pull to the left!!!
I will replace the left one next,,the lines are more than the calipers!! how messed up is that??!!
Now under a hard braking session today my pads cracked,dang always something right,they were old anyway an were gonna need replaced soon anyhow.
Thanks guys for all the input!!!!!!

 

Agreed, you should always replace in pairs because if one is bad chances are the other one can't be far behind. Especially, for brakelines and calipers.

Later