Rebuilding Calipers: Front piston won't go back in

[DrewC]

I've rebuilt the front Girling brakes but I've torn 2 dust boots trying to get the clean piston back in there. The rears were a breeze, the piston would slide in just a hair to seat up straight and square, but the fronts keeps going in crooked, jamming up and tearing the outer boot seal.

Help!

Thanks :)

[DrewC]

I just read the pelican parts article and the dust boot part didn't make sense to me.

[DrewC]

Note to self: C-clamp does not produce the amount of force as tapping with a hammer.

It felt super tight, but apparently tapping the hammer delivers a much more potent punch and the caliper went right in. I also ended up playing with the boot more, and that helped a lot.

Carry on.

[Gooch]

Thanks for posting up your solution...I'm going to have to do this soon. I was going to point you to the DIY thread on this with pictures, but you've got it covered.

[DrewC]

Thanks for posting up your solution...I'm going to have to do this soon. I was going to point you to the DIY thread on this with pictures, but you've got it covered.

I read it but it wasn't good enough. I was tearing the boots because I seated them and then tried to put the piston in. False.

Slide the boot over the piston and pull it all the way down (don't let it seat it self on the piston's groove near the brake pad contact area). Slide it down and let the boot hang off the bottom of the piston enough to seat on the caliper. VERY delicately (as not to let the boot slip off the piston) seat the seal on the caliper, and then press the piston back in and once it's all the way in the pistons' groove will seat with the boot's ring.

[Beej '86 325es]

Rebuilding the front girling calipers takes a special talent. You need 8 muscular childs' hands to get the damn dust boot on.

[DrewC]

Rebuilding the front girling calipers takes a special talent. You need 8 muscular childs' hands to get the damn dust boot on.

Once I figured out my style for doing it, it was a cinch. After doing the first one, I did the 2nd in no time.

[bmwpower]

Where are you getting your parts?
How often are you going to rebuild them?

[DrewC]

Where are you getting your parts?
How often are you going to rebuild them?

Got them from Pelican. I don't think they need to be rebuilt very often if you flush your fluid once every year or so. The seals looked in great shape, the calipers were just gunked up. I just got the car, so I have no idea if they were original or have been replaced in the life of the car.

[bmwpower]

Got them from Pelican. I don't think they need to be rebuilt very often if you flush your fluid once every year or so. The seals looked in great shape, the calipers were just gunked up. I just got the car, so I have no idea if they were original or have been replaced in the life of the car.

By gunked up, what do you mean? Sorry, never rebuilt one but sounds like it would be easy and worthwhile for optimum braking.

[Beej '86 325es]

Rebuilding the front girling calipers takes a special talent. You need 8 muscular childs' hands to get the damn dust boot on.

BTW, I have a whole front brake package for sale, including 2 rebuilt and unused Girlings (all new parts except the caliper and piston) - $150 for calipers shipped to lower 48.

[andrewc53]

I take the piston and put a little grease on that and on the O rings and hold it up to the caliper dust seal and blow compressed air in form the brake line hole to get the dustboot over the piston and they slid in by hand every time

[Cloudbase]

I read it but it wasn't good enough. I was tearing the boots because I seated them and then tried to put the piston in. False.

Slide the boot over the piston and pull it all the way down (don't let it seat it self on the piston's groove near the brake pad contact area). Slide it down and let the boot hang off the bottom of the piston enough to seat on the caliper. VERY delicately (as not to let the boot slip off the piston) seat the seal on the caliper, and then press the piston back in and once it's all the way in the pistons' groove will seat with the boot's ring.

It seems like the Pelican procedure is for the rear brake dust boot along with later model ones. The wisdom above just saved me after spending an hour frustratingly trying to get that fucking boot on. Thanks man!