Brcmpbl

I'm rebuilding a rear caliper with a lip seal kit from one of the vendors, and I can't seem to get the dust boots to seat. Last night I finished a pile of brake work, including rebuilding the right rear caliper. I had to re-use a couple of the old dust boots because the new ones weren't tight enough in the caliper - they just popped in without much force, and popped back out similarly. Anyway, I thought I had them seated finally, bled the whole system, got in the car to test the pedal (manual brakes), heard a little pop, and found a bunch of fluid on the floor - one of the outer dust boots had popped out.

Anyone else experience this?

hzz

The rear dust boots are usually no problem.
I find the front ones tougher to seat.

The only thing that doesn't seem right is that the dust boots are there to keep the dirt and dust from getting into the bores, not to keep the brake fluid in.

If you had a leaky caliper it was the lip seal, not the dust boot.

I use o rings when I rebuild my calipers and have never had a leaky one, so far, anyway.

Brcmpbl

Yes I definitely did not get the lip seal installed properly. Have to have another go today. Some of the pistons were really hard to get installed with the new seals on them.

The dust boot acts as a type of retainer though, doesn't it?

I still find it odd that the dust boot won't hold itself in once seated though - it is just very loose in there, despite being installed flush with the caliper surface.

I'm an o-ring believer - had them on a different Corvette I had and I found them to be maintenance free. I just don't have the time right now to order those up and rebuild both of the rear calipers for them. Time is tight this summer. That's the future though.

DUB

YES...the dust boot is a retainer to keep the piston in.

Keep in mind that not every company makes parts the exact same..so another company may have an outer seal ring that will be bit larger and allow it to stay in place without using any sealant to hold it in place.

DUB

GUSTO14

DUB, correct me if I'm missing something, but if the piston is seated correctly in the bore, the dust boot is installed correctly and the caliper is mounted on the spindle/control arm with brake pads installed, the only way to blow the dust boot off and leak fluid is if the seal on the piston fails first.

I understand that the dust boot helps retain the piston during assembly, but once the caliper is mounted with brake pads installed, there is no way for the piston to move far enough out of the bore to unseat the piston seal... is there?

GUSTO

RonR80

I had the same issue with a re-build kit from Summit , so I bought a kit from Napa and the dust boots snapped right in , not sure why but the 1st dust boots were a bit small ,

Brcmpbl

Thanks guys.

Ron - that's exactly the issue. There's hardly any interference in the fit of the boot ring at all. I can move it around with my finger. I'll try a NAPA kit. Can't have the car off the road for too long given the weather we're getting here in the Maritimes at the moment.

revitup

Isn't that seal just a rubber boot with a u-shaped cross-section metal ring around it? Couldn't you just spread that ring a little to get the interference fit you need?

RonR80

I don't think so it's covered not even sure why some won't fit .

I can dig up the Napa number if you want it . I just received 2 New Brunswick flags in the mail , my wife is from F'ton

DUB

YOU ARE CORRECT....100%.

But if the dust boot seals are not installed correctly and not able to keep the piston from coming out. ESPECIALLY if lipped seals are being used on the pistons....and ASSUMING that the springs are also being used. I would hate to be the person who have to get all four pistons in and compressed so I can install pads and then slide the caliper onto the rotor.

KEEP IN MIND...that this dust boot seal is also trying to keep the exposed bore of the cylinder of the caliper CLEAN...because when the brake pads wear out,,,the piston comes out closer to the rotor...thus the piston seal needs to be able to seal against a good clean surface. IF the dust boot seals are not correct...then crap and dust, etc can effect the surface of the bore and cause to the seals to fail.

DUB

Brcmpbl

Well, I tried several different dust boots and none would go in the casting with a good interference fit - all were loose. One was less loose, so I used that one and some RTV for now to hold it in. I'm going to replace the caliper for my own piece of mind.