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Front brake trouble

dcmargush

By dcmargush
in Ask A GM Technician

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dcmargush Enthusiast

dcmargush

Posted
Posted

1999 Silverado 2500 4wd.

 

When I changed the pads on the front of the truck, I have encountered an odd happening.

 

I am using ceramic pads (should not be an issue here cause the problem happens before the material would make a difference).

 

I use a large "C" clamp and retract the pistons while the caliper is still on the bracket, remove the pins, replace worn pades with the new pads, lube (with anti seize) pins and the shims on the caliper (where the pads slide), reinstall the pins.

 

Here is where the problem comes in. the top pin goes in fine, while tightening the bottom one the rotor locks up. Let me go into alittle more detail here. I have made sure the free floating rotor is on straight (installed 2 lug nuts), the pistons are fully retracted and both are free (if I retract one the other one protrudes and vice versa). with the top pin in, I can turn the rotor (while it has resistance I can still turn it by hand). As i start to tighten the lower pin, the rotor gets tighter and tighter til I can no longer turn the rotor. At this point the pin is about 1/2 way threaded in to the caliper. I have though that it could just be the tension of the new pads and lack of leverage on the rotor, so I install the wheel, and I still cannot turn the wheel by hand.

 

this is on the passenger side, the driver side went together just fine.

 

the only way I can reassemble and function is with the old worn pads (nearing and closer to end of life than when I started).

 

Any ideas?

95Sierra2500 Senior Enthusiast

95Sierra2500

Posted
Posted

You're definately binding somewhere. Perhaps your caliper isn't sliding on the pin properly? I've not dealt with the fronts, but I know on the rear the pins usually lock up. Maybe you need to clean everything out, perhaps some rust or some other foreign material in the bottom of the pin hole?

dcmargush Enthusiast

dcmargush

Posted
  • Author
Posted
You're definately binding somewhere. Perhaps your caliper isn't sliding on the pin properly? I've not dealt with the fronts, but I know on the rear the pins usually lock up. Maybe you need to clean everything out, perhaps some rust or some other foreign material in the bottom of the pin hole?

 

 

 

 

 

Good though, should probably do that. But why would it not bind with the old pads in??? :cheers:

95Sierra2500 Senior Enthusiast

95Sierra2500

Posted
Posted
You're definately binding somewhere. Perhaps your caliper isn't sliding on the pin properly? I've not dealt with the fronts, but I know on the rear the pins usually lock up. Maybe you need to clean everything out, perhaps some rust or some other foreign material in the bottom of the pin hole?

 

 

 

 

 

Good though, should probably do that. But why would it not bind with the old pads in??? :cheers:

 

 

 

 

 

Because the old pads are wore down enough that when everything is bolted up properly, they probably barely touch the rotor.

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