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I just finished rebuilding the brake calipers for our first race this season. When setting a ball park bias I am faced with a problem. My goal is to start with a conservative dry setup slight to the front. Here is my problem. I am able to get both the rear brakes in sink with each other but not the fronts with each other. I am satisfied with setting for the right front and the two rears, but the Left front does not engage in sink with the right front. It engages quite a bit later. I have checked the brake lines and bled the brakes and am confident there is not air in the system.

There is one potential issue that could be the problem. The top of one of the pins on the left front was warn to a point that the proper socket size would not fit, the way it should have. As such I decided to replace the pin to avoid having a problem getting it out later. My problem is that the only spare pin I had was one of the old style pins which is wider than the new ones. I installed the old larger busing with the old larger pin thinking that shouldn't cause a problem as long as I was using the proper size busing with it.

So my question is what are the possible problems causing this issue? Could it be using different size pins for the same caliper even when doing so I used the correct size bushings for each size caliper pin?

Thanks in advance for your help. Pat

Check that the pins are parallel. If they have been over tightened or if there it dirt on the seat of the bracket one can be at an angle causing the caliper to bind.

To check remove the rotor and pads, so you just have the caliper on the pins and be sure it slides freely.

How about taking the right rear caliper,pins,pads all of it and put it on LF and LF on RR. Yes it is time and fluid to bleed system but it will tell you if there is a problem with something. If there is it should move to the RR. If it does not then will have to be in line, braided or metal. Master does not know what tire it just applies pressure.

A quick way to see how and what your bias is without a pressure sensor is to use a torque wrench. Have someone sit in the car and apply the brakes, then measure the torque to rotate the front and rear tires. This will give you an idea if you are in the range and you can use it to be sure the front and rear are labeled correctly. Bruce

If the head of the pin has been stripped, it sounds like they've been over-torqued. This may result in "mushrooming" of the pin at the seat of the caliper, which can cause the pin to be off-center and impacting the free movement of the caliper on the pin. It may be worthwhile to change all the pins and bushings so that everything is at an equal state of wear. I agree with Lee's suggestion of checking the free movement of the calipers on the pins so ensure they're parallel and not binding.

Since you mentioned a full rebuild, I assume you've changed the inner o-ring and dust seals on the calipers? That o-ring affects the "pull back" of the piston after the brake is released and that could affect the distance from the piston to full compression of pads on the rotors if there's any internal binding. This does not necessarily impact the pressure at the pad under normal braking, so static testing, like Bruce's suggestion, while useful for testing a major issue like a bleed or static binding problem, won't substitute for a real-world test, since the forces on the pins that may cause issues are not generally how soon the piston hits the pads, but binding under full braking loads.

Note that with the Hoosiers, the brake bias is much closer to 50/50 than the Goodyears, which required much more front bias. It's easy to "overload" the front tires when cold, so a careful touch is needed while getting them up to temperature to avoid flat-spotting. With a good front/rear balance, the potential braking levels are pretty impressive.

Jeeez, there you go sharing again, Bob.