When to rebuild Calipers?

mm86911 · mm86911's Garage

Just prepped new rotors and ready to mount Hawk HP Plus pads. Also have caliper rebuild kits on deck. No easy access to air compressor. Questions is: If calipers are performing well (no sticking) should I rebuild them while everything is apart (assuming dust boots look good - if not, just replace dust boots?)?

john_colasante · 07-12-2002, 07:08 PM

I recently went through my entire brake system including new rotors, rebuilt calipers, Pagid Orange pads and new stock rubber lines primarily for track work. Big improvement. If you've got a braking system with 10-15 years on it with basically no maintenance and you're tracking the car it's time to do those calipers. The car won't necessarily stop sooner but it feels more "sure" with new components. I was juggling with brakes that kept verging on lockups at inopportune times under threshold braking. Once I rebuilt the whole system I no longer have this problem and I can go deeper into the corner with a higher confidence level. Do it.

slakjaw · 07-12-2002, 08:52 PM

if you rebuild them right

it shure wont hurt anything

might be hard with no air tho

autobonrun · autobonrun's Garage

both to pressure brake fluid through the lines and also with air only in the cannister to force the caliper pistons out. It doesn't take much air pressure to get them to move. I just bought a few fittings to go on the end of the sprayer's hose. Slip a tube over it and connect the hose to the reservoir overflow fitting. Made a great pressure bleeder. Just get the hose long enough to reach the wheels then you can do the job by yourself and make sure the top is on the reservoir tight.

Probably self explanatory but the pressure sprayer was new (about $19 bucks). Didn't want to chance getting diazinon in my brake calipers; though it will probably keep the bugs out.

If you want to try this take the correct size hose that fits on the reservoir to the hardware store with you then get a sprayer where the nozzle screws off. Assemble the fittings there to make sure you have the right ones, then put teflon tape on the fittings when you get home. I keep this setup dedicated for brake fluid changes.

Doug E · 07-13-2002, 02:23 AM

I agree that if you've got everything apart and at around $10 per kit it is well worth it.

Try a local gas station and see if for another $10 or $20 they'd blow the calipers out for you. Just make sure to take the following:
1) small pieces of wood to fit between the pistons to prevent them from flying out
2) rags/towels to wrap the caliper in when in the vise and also to lie underneat the bench in case the piston drops
3) 8 plastic baggies so you can keep the pistons clearly identified with the correct caliper location because you don't want to mix them up

The advantage of a local service station is that their compressor is usually bigger than 100 psi and sometimes that is needed.

Good luck.

ChrisL · 07-13-2002, 03:46 AM

You're going to need air. I just finished mine on an '86 and although the pistons weren't scored, there was some rust and grime from where the dust boots were torn. Felt good to get that cleaned up and new boots on.

Chris.

Chuck Moreland · 07-13-2002, 08:51 AM

You don't need an air compressor.

Use a bicycle pump and a piece of hard brake line.

Roland Kunz · 07-14-2002, 02:11 PM

Hello

Whenever I see the rubberboot wrinkled, torn, or punched it is time to "rebuild" before dirt and rust take a bite.

Grüsse

mm86911 · mm86911's Garage

Thanks for all the replies. Contacted the previous owner and turns out he rebuilt them only 2 years ago. Suspect such as there was anti-sieze on the mounting bolts and all boots looked new.

Finished the job today with new rotors (stock) and Hawk HP Plus pads. Repacked the bearings, bled the system again with ATE Blue (been using that for some time - plus boiled it last track outing so peddle was soft. "Bedded" the pads per Hawk instructions but seems to pull to the left under hard braking. Will drive it further and see if things settle. BTW - stopping power is great (wanted a dual purpose pad so I didn't have to change for each track event - call me lazy) but, as suspected, dusting is more than stock. Good thing is the dust is "harder" so it wipes off quite easy. So far, pleased with the selection.