The front brakes will not slide?

Hi,

I need to better understand what is happening. Do you mean when the brakes are applied, the rear wheels lock up? Does the vehicle have rear ABS? Is the axle assembly that was used in the replacement the same as the original one?

Let me know.
Joe

I have seen times where an axle seal leak or wheel cylinder leak will cause a wheel to lock up. However, I suspect you have already checked that. The only other thing I can think of is the brake pressure modulator. If the vehicle originally had rear abs and now doesn't, it is even possible that the brake lines were attached incorrectly at the module. Did you do the work?

Hi,

There is no "ABS Sensor". Each wheel has a wheel speed sensor. Is the ABS light staying on in the vehicle?

As far as the ABS module, it is under the vehicle. I attached a pic of it.

Joe

I thought the vehicle originally had rear ABS. If it did and the new axle doesn't, the light should be on.

Do me a favor. Remove the ABS fuse and see if the same thing happens. I attached a pic to help you locate it.

Joe

Hi,

You had be stumped when you said it wasn't on. LOL Anyway, remove the ABS fuse and see if it stops doing it. If it doesn't, then we know it isn't ABS related. By removing the fuse, you will lose abs control but not lose the brakes.

Let me know.

Joe

The wrong axle? Is this 4wd?

Okay. I thought they mixed up gear ratios between front and rear. Are you going to replace what you have at this time?

From the description and reading through it it looks like the rear brakes are not set up the same as the originals so the fluid balance is wrong and the rear brakes are locking up when they shouldn't be. I have seen this happen if someone swaps a rear disc brake axle into a truck that had rear drums as the proportioning is now wrong. About the only way to repair it is one of two things, replace the rear axle with one with the correct brakes, or replace the master cylinder and ABS system with the one that matches the current brakes.

You're welcome. What you can do is check the RPO code sticker, usually in the glove-box it will tell you which rear the truck came with. Then you can determine the easiest way to repair the problem. The discs are a nice upgrade but all the parts need to match or you can have some serious problems. For the cheap way to do that I suggest visiting a salvage yard and find a truck set up that way, it will let you get all the parts to match your set-up. There is also a load sensing valve in the rear of some versions that adjusts the rear brakes depending on the load in the box. You might want to see if your truck uses it and if it was connected as they could cause excess brake activation in the rear if it wasn't connected.

The only thing I can think of would be the ABS valve itself causing this. Can you lift the rear of the truck then start the engine and let it idle, then barely touch the brake? I want to see if the brake slow the wheels or they just stop (lock up) if so both? Do you have gear oil on the pads/rotors? Can you please shoot a quick video with your phone so we can see what's going on? That would be great. You can upload it here with your response.