Brakes - compressing the piston and advice

[dtrain]

Been reading up but couldn’t find an answer (could be in the FSM but of course I could not find it last night)

Holding off on the 4runner upgrade for now. I need to spend the bucks in other places (bad exhaust leak, need a tune-up, shocks and tires)

Pulled my wheel and started changing out my pads. Pulled off the caliper and then realized that I did not need to do that – put it back on. Pulled the pads - (1) first pad had really bad uneven wear from top to bottom. It was a very obvious slant. Almost like one piston was stuck open for a while. (2) The second pad was about as thin as 3 pieces of printer paper. There was still some pad but not much. The rotor did not have any “maring” or grooves from the pads and looked to be smooth. However, there was a lip on the outer edge of the rotor. Does this need to be replaced?

Obviously the new (semi-metallic) pads were “taller” so I need to compress the pistons to get them to fit. Any ideas? Is the best option to just open the bleeder and then re-bleed them?

Still have to do the other side.

Any help and/or advice is greatly appreciated

 

[lehiguy]

Been reading up but couldn’t find an answer (could be in the FSM but of course I could not find it last night)

Holding off on the 4runner upgrade for now. I need to spend the bucks in other places (bad exhaust leak, need a tune-up, shocks and tires)

Pulled my wheel and started changing out my pads. Pulled off the caliper and then realized that I did not need to do that – put it back on. Pulled the pads - (1) first pad had really bad uneven wear from top to bottom. It was a very obvious slant. Almost like one piston was stuck open for a while. (2) The second pad was about as thin as 3 pieces of printer paper. There was still some pad but not much. The rotor did not have any “maring” or grooves from the pads and looked to be smooth. However, there was a lip on the outer edge of the rotor. Does this need to be replaced?

Obviously the new (semi-metallic) pads were “taller” so I need to compress the pistons to get them to fit. Any ideas? Is the best option to just open the bleeder and then re-bleed them?

Still have to do the other side.

Any help and/or advice is greatly appreciated

You should be able to work them back into the caliper, the displaced fluid returning to the master cylinder. The rotors on these rigs have very little to give in terms of material. They will be under the limit after one turn usually. So if they are looking bad, you might plan on replacing them.

 

[dtrain]

Does the lip on my rotor sound like they are "looking bad"?

 

[Dynosoar]

The pistons in the calipers should compress easily with a pair of channel locks. If not, you may (and it sounds like you do) have a frozen piston.


Dynosoar

 

[dtrain]

The pistons in the calipers should compress easily with a pair of channel locks. If not, you may (and it sounds like you do) have a frozen piston.

Dynosoar

Great tip to use the channel locks... worked perfect. No frozen pistons. Took me about an hour to button up the side I was working on and get the other side done.

Beginner tip I guess... I compressed 3 of the pistons and the 4th pushed itself out against the caliper and would not budge. Good that it moved but it was not budging. Got something between the caliper and the piston to pry (careful not to mar caliper) it out and at the same time cracked bleeder valve. As soon as I was done applying leveravge to the piston I tightened up the bleeder. It released just enough preasure to compress the 4th piston to where I needed it.

Topped off the resevoir and took a test drive. Got back and jacked up each wheel to be sure it would spin freely - it was like butta. Everything worked great. Major difference in stopping power.

Thanks to those that posted tips and help!

 

[sdbrassfield]

A big C-Clamp works great too to compress the piston...

 

[dtrain]

A big C-Clamp works great too to compress the piston...

The way the calipers are designed - I counld not get a clamp in there.. especially if it was mounted. I never had to remove the caliper to replace the pads.