Rear left locking up after work on brakes

[Lomoski]

Hey Gang,

As the title states, I was doing rear brakes on my KZJ78 today. I put in new pads, Cleaned and lubed the pistons and bled both sides. Now when I brake hard my rear left locks up before anything else and definitely not at the same time as the rear right. I had adjusted my LSPV when I did my lift last year and my rears would normally lock up just after my fronts. Would new pads and working pistons (they where gunky and pretty sticky, left side pad had worn more than the right) cause that much of a difference that I would have to readjust my LSPV? If so, it's been a while, what direction do I go again to move the braking forwards? Also why is my left locking and not my right, pretty confident the bleed is good.

Thanks guys,

Marc

 

[roscoFJ73]

Would new pads and working pistons (they where gunky and pretty sticky, left side pad had worn more than the right) cause that much of a difference that I would have to readjust my LSPV

The LSPV doesnt regulate brake pressure to left and right , it does it to the front and rear. So technically, it doesnt really come into it
And you were having problems with the left hand side pads wearing out before the new pads went on means there was already a problem.

Also why is my left locking and not my right, pretty confident the bleed is good

It can only be a bad caliper or still has some air in the lines.
Are you bleeding the wheel furthest from the master cyl first?

 

[Lomoski]

The LSPV doesnt regulate brake pressure to left and right , it does it to the front and rear. So technically, it doesnt really come into it
And you were having problems with the left hand side pads wearing out before the new pads went on means there was already a problem.



It can only be a bad caliper or still has some air in the lines.
Are you bleeding the wheel furthest from the master cyl first?

Thanks for that. I know the lspv only regulates front to back pressure, I think the new pads and calipers that actually move. (I took them both apart, cleaned the pots and re installed with brake caliper grease on the pots and under the rubber baffles). When I bleed the brakes I did rear left, rear right, lspv, front left and then front right. I'm not sure why the rear left would still be biting more after a caliper rebuild. They were very gummed up and not working could barely spin the rear left, but they definitely are now. Might try rebleeding the whole system again this weekend but I'm pretty confident there is no air in the system now.

Thanks for the input. Not sure what else I'm missing.

 

[CharlesHS]

You should recheck the operation of the rebuilt caliper once the truck has been driven for a while; the caliper may perform differently once it warms up.

 

[Lomoski]

You should recheck the operation of the rebuilt caliper once the truck has been driven for a while; the caliper may perform differently once it warms up.

Thanks Charles,

I'll recheck everything on my next set of days off and make sure it's still working as expected. You think it will loosen up with some driving or cause the locking to get worse?

 

[CharlesHS]

While there is a chance it will loosen up; my experience is that it will only get worse.
To me it sounds like the caliper has a problem and should be replaced.

 

[Lomoski]

While there is a chance it will loosen up; my experience is that it will only get worse.
To me it sounds like the caliper has a problem and should be replaced.

Good info, Thanks.

I'm not sure why having a clean/lubed piston/pot, and non leaking seals on that caliper would be worse than the way it was before though or what I would gain by replacing it. What am I missing there.

 

[CharlesHS]

There may be something internal to the caliper that is hindering full bleed off once the brake pedal pressure is released that causes the pads to drag on the rotor.

 

[Lomoski]

There may be something internal to the caliper that is hindering full bleed off once the brake pedal pressure is released that causes the pads to drag on the rotor.

It's definitely not dragging anymore than the right. Did a pull test with a spring after driving and a bleed. It just seems to lock up before the right one. I'll drive it a bit and then see how it is again and maybe replace. Just hate spending money on something that seems fine otherwise. Appreciate your input though mate