Bloodzone

Calipers are 2 years old. Car started pulling towards driver side when breaking. Changed out pass side rotor (I had one already), bled breaks and was great for first few stops then pulled again. Bled brakes again with motive power bleeder. Did same thing perfect for first few stops then pulls more and more. Pedal feels fine (maybe just a little soft). I'm thinking its must be the caliber sucking in air. Anyone have any suggestions before I order a rebuild kit? Or could something else be causing my problem? Thanks for any help.

silver74vette

Did you get any air out when you bled the brakes? If you did, was it right away or after a while? I have not really seen a caliper that was not leaking let air back in but this could be a first. I would go over the whole system, lines and all and look for leakage. Usually I find if air is getting in, fluid is getting out.

71VetteLover

Before wasting any money put a dial indicator against the face of all four rotors and see how much run out they have. It's run out that causes air to be pumped past the piston seals so you need to measure that first.

Bloodzone

Yes I did get air. Right away too but only on 1 side of the caliper. the other bleeder zero air both times.

Bloodzone

I'll have to take it to the shop for that. I dont have a runout gauge

Bloodzone

Just want to add that I've had no problems in 2 years with these brakes.....till now. Problem started couple weeks ago without warning.

silver74vette

Good point by 71Vette.

It sounds like you had the same issue with two rotors on that side, and you are getting air in the caliper, not someplace else. Are you getting a pulsing on your brake pedal when you apply them? Typically you can feel too much runout. Also you may check your wheel bearings, make sure they do not have slop in them. I have checked runout by clamping a bolt to the caliper mount and using a feeler guage between the rotor and the bolt at 90 degree intervals. If you have over 2 thousandths runout that could be your problem. I would also pull the caliper and look for signs of leakage. Even if you find another issue the caliper kit is probably still a good idea.

Bloodzone

My rotors are drilled/slotted only have 1/4" area on the outside to check runout. I'll buy a gauge and do it myself.

No pulsing just a hard pull. You can really feel the pull at low speeds. a 20mph firm stop will pull the car into left lane if you let go of the wheel.

Time to do a little shopping.

silver74vette

By the way, great looking car, I love that color and the hood!

Bloodzone

Thanks

It would really be nice if it would brake straight.....its always something with these cars but I love'em.

cagotzmann

The only time I have seen air in the caliper is from over heating the brake fluid without fluid leaks. Air in requires fluid out usually.

If you get pulling to one side after a few stops I would check the pad material. As the pads heat up they should grip better. If its pulling to one side it could be something loose in the suspension / Tie Rod / Ball joint, contaminated pad material on one side.

It would be very unlikely you would get enough air in to cause this effect after a few stops only without leaks.

Also if the pads have worn down to the point of requiring replacement it is possible to get air trapped behind the piston when bleeding. I usually push the pistons/pads in completely before bleeding.

Bloodzone

Car starting pulling a month ago. I had new upper/lower control arms and coilovers installed 2 weeks ago. So the suspension should not be a issue. Pads are at 75% or more. I can find no leaks and the shop found nothing while doing the control arm install. They also switched out the rotor so they were all over that wheel. Its really a crazy issue thay I can't find a simple solution for.

silver74vette

Just a thought, are the brake hoses in good shape? Have you tried to take a temp reading and see if there is a difference between right and left?

SteveG75

Call Wilwood customer service. First I have ever heard of a D8-4 sucking air. They may want it back for examination.

Bloodzone

Hose is Wilwood braided. I've not taken a temp reading but it starts pulling before temp could rise. And the brake fluid flows perfect and clean when bleeding. So I dont have any blockage.
I may if I'm 100% sure the problem is in the caliper. I'm just pointing fingers at this point. I still need to check the runout.

Its seems impossible for the car to pull as much as it does without the problem being obvious.

Thinking about switching pass and driver side calipers and see if problem follows the switch.

Bloodzone

Just noticed this...... Pulls more after brakes heat up. Pulls only a little at cold start but gets worse after a few stops.

silver74vette

So the passenger caliper gets weaker with temp. Does it get better once it cools off again? I think you can rule out Master Cylinder and your combination valve should not cause it so it sounds to me like the caliper or brake hose. Could something have been bent or stressed during the recent suspension work? Did it start right after anything was done or just start?

Bloodzone

Yes, its much better cool. Only takes a few stops to start pulling again.
It started outta the blue couple weeks before ssuspension work .

The rotor is not as shiny from the pads as the driver's side is. So I know it was weak but with the car in the air and someone holding the brake pedal I could not turn the wheel by hand.....but the car was cool, I'm betting if it was hot I could move it.

hope2

Reverse the calipers side to side.

Bloodzone

That would point the finger or rule out the caliper for sure.