Caliper Piston Removal
Thread Starter
Pro
Joined: Jan 2019
Posts: 558
Likes: 83
From: Tallahassee, Florida
Caliper Piston Removal
Hello,
My new (used) Z51 calipers arrived today. However, the seals are shot and need to be replaced. Also, I want to paint the caliper.
How can I remove the pistons? I read that compressed air does the trick, but I don't have an air compressor...
Thanks a lot!
My new (used) Z51 calipers arrived today. However, the seals are shot and need to be replaced. Also, I want to paint the caliper.
How can I remove the pistons? I read that compressed air does the trick, but I don't have an air compressor...
Thanks a lot!
Le Mans Master
Joined: Dec 2004
Posts: 5,492
Likes: 808
From: West coast CA
A word of caution: if you use compressed air, even at a relatively low pressure, the piston will pop out faster than you can believe. Stick a block of wood in the caliper so the piston doesn't come all the way out. Keep your fingers out of the way or they will get smashed. The caliper is a power-operated clamp, after all.
Inspect the new seals and dust covers to make sure they're the right size. I've seen a lot of AC Delco rebuild kits with the wrong seals in them.
Clean up everything with denatured alcohol. Lubricate the new hydraulic seals with a drop of hydraulic brake assembly fluid (such as Centric p/n 500.1000) and they'll go in really easy. It works way better than brake fluid. Note that this is not the same stuff that you use to lubricate the slider pins.
Thread Starter
Pro
Joined: Jan 2019
Posts: 558
Likes: 83
From: Tallahassee, Florida
You need compressed air. You could probably do it with a bicycle pump and one of those conical plastic ball inflator fittings.
A word of caution: if you use compressed air, even at a relatively low pressure, the piston will pop out faster than you can believe. Stick a block of wood in the caliper so the piston doesn't come all the way out. Keep your fingers out of the way or they will get smashed. The caliper is a power-operated clamp, after all.
Inspect the new seals and dust covers to make sure they're the right size. I've seen a lot of AC Delco rebuild kits with the wrong seals in them.
Clean up everything with denatured alcohol. Lubricate the new hydraulic seals with a drop of hydraulic brake assembly fluid (such as Centric p/n 500.1000) and they'll go in really easy. It works way better than brake fluid. Note that this is not the same stuff that you use to lubricate the slider pins.
A word of caution: if you use compressed air, even at a relatively low pressure, the piston will pop out faster than you can believe. Stick a block of wood in the caliper so the piston doesn't come all the way out. Keep your fingers out of the way or they will get smashed. The caliper is a power-operated clamp, after all.
Inspect the new seals and dust covers to make sure they're the right size. I've seen a lot of AC Delco rebuild kits with the wrong seals in them.
Clean up everything with denatured alcohol. Lubricate the new hydraulic seals with a drop of hydraulic brake assembly fluid (such as Centric p/n 500.1000) and they'll go in really easy. It works way better than brake fluid. Note that this is not the same stuff that you use to lubricate the slider pins.
Slider pins are the attachment bolts, right? They seem to have some sort of grease on them. Can you advise on that?
Le Mans Master
Joined: Dec 2004
Posts: 5,492
Likes: 808
From: West coast CA
The sliders are the pins that link the two halves of the caliper. The pins are fixed on one side and slide inside a bushing on the other. They're inside a rubber dust cover. You can get grease for those anywhere. Sil-Glyde is a popular brand.
Thread Starter
Pro
Joined: Jan 2019
Posts: 558
Likes: 83
From: Tallahassee, Florida
I got the rear pistons out!!
However, the next hurdle is the banjo bolts. I managed to get one off, but I literally had to use my foot to knock the bolt off with the wrench! Now, the bolt is stock in the socket.
I am concerned that the banjo bolts will be this difficult to get off the calipers that are currently on my car when I go to do the swap. Any advice?
Also, I am thinking that the banjo bolt is stuck in the socket because the socket I used is just a hair too small. What is the proper socket I should go buy?
Thanks so much!
However, the next hurdle is the banjo bolts. I managed to get one off, but I literally had to use my foot to knock the bolt off with the wrench! Now, the bolt is stock in the socket.
I am concerned that the banjo bolts will be this difficult to get off the calipers that are currently on my car when I go to do the swap. Any advice?
Also, I am thinking that the banjo bolt is stuck in the socket because the socket I used is just a hair too small. What is the proper socket I should go buy?
Thanks so much!
