Caliper cylinder seals

[Jean-Marc]

Guys,

Had my black calipers powder coated red. Great stuff, however the guy that did the job did not mask the seals and there are now ready to crack (not because of the heat, because of the paint...).

I ordered replacement seals from Gert but I am struggling understand how to install them and cannot find anything about them in the workshop manuals...

Anyone can help?

Thanks

JM

[ar38070]

You just pop them off and put the new ones on. I have heard of people doing it without removing the caliper. I remove the pads and then take the caliper off the wheel carrier. It makes it easier to get at the seals.

If you look at the new one you will see that the outer lip is stiff as I think that there is a metal stiffener embedded in it. That lip is a press fit in a groove in the caliper. The middle of the seal is flexible rubber. There is a groove around the caliper piston. The flexible rubber part of the seal seats in this groove.

You need to work the outer part of the old seal out of the caliper. A flat head screwdriver works fine. Just push it into the side of the seal that you should be able to see and pry it up. Then work it loose all the way around. You can then stretch the inner part of the seal away from the piston and then lift it off the piston.

Be careful when you are removing the seal from the piston. You do not want to pull the piston out of the caliper. Makes a huge mess.

[Jean-Marc]

Thanks for that. I do have the old ones off already. Do you mean that I just need to pop them in the new ones? It seems very odd as the bit that needs to go under the groove under the piston will presumably never catch the lip then....

Maybe I didn't get it. I thought that I needed to get the pistons out first...

Any further clarification you can give me would be greatly appreciated

Thanks

JM

[ar38070]

You do not want to take the pistons out unless you plan on bleeding and refilling the brake fluid. The fluid is right behind the piston. Also it is very hard to get both pistons out without disconnecting the caliper from the brake line. You do not want to grab the piston with a pair of pliers as the material is not that hard. I have been told that you usually use compressed air to pop them out. Again I would not do this.

Attached are two pictures. These show the piston out but again you do not need to do this. The piston just needs to extend far enough out so that you can get to the groove. If the piston is not out far enough so that you can see all of the groove then have someone press gently on the brake pedal to get the piston to extend. Alternately usually if you push one of the pistons in the other will extend. Once you have replaced the seal on the first piston push it back in and the other one will extend.

The first picture shows the new seal installed on the piston. In the second picture I pushed the outer part of the seal down so that you can see that the inner part of the seal is seated in the groove in the piston.

When you first put the seal in the groove on the piston it will probably be twisted, just grab the outer ring and spin the seal around the piston and the seal will straighten itself out. Now press the outer part of the seal down against the caliper to seat it in the groove that is there.

[ar38070]

Second photo

[Jean-Marc]

Many thanks for taking the time to do this for me. See the issue, is that my calipers are currently off (had them powder coated red) and I couldn't find out how to get the cylinders to pop out gently... I guess I'll do it once they will be connected to the brake system

Thanks again

JM

[danjen]

I've got my calipers off (pads out) and am ready to have them powder coated. It sounds like I need to pull some seals out before they are painted??

Can anyone give me advise on how to do final prep (prior to powder coating) of the calipers?? I definitely don't want to have to replace parts prior to re-installing.

Also, I have heard several comments about replacing the caliper bolts. What is the "common practice" if there is one.

Thanks

[ar38070]

If the pistons are out then just make sure that they do not get anything inside the piston holes.

Bolts can be re-used.