Caliper Boot Was Loose When Changing Pads

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Changing front pads and rotors on my 98 Expedition 4x4.
When I removed the caliper from the drivers side, the lower boot was not seated in the piston bore casting.
Here is a picture of the boots I am referring to. Keep in mind I removed both boots for inspection and cleaning. Only one was not seated properly upon removal of the caliper. They both seat with finger pressure and both can be removed without tools as well. The boots are in good condition still.
Is that how tight they are supposed to be, or should I be using some sort of sealant to secure the boot to the caliper housing?
[Linked Image]
 
I had that happen on my BMW a while back, to me the worst problem is the rust on those pistons. I can't imagine they will seal properly when you push them back into the caliper for the new pads.

I've never glued the boots into the caliper but I do make sure the groove is clean and that the boot is seated properly all the way around. Sometimes it is difficult to seat the boot and if it isn't completely in the groove it will definitely pull out as it has done in your picture.
 
Originally Posted by Chris142
Needs a caliper. See all that contamination on the pistons? When you push them back in thats going to cause problems.


What about pulling the pistons and cleaning them with a scotch-bright pad?
 
Originally Posted by MarkM66
Originally Posted by Chris142
Needs a caliper. See all that contamination on the pistons? When you push them back in thats going to cause problems.

What about pulling the pistons and cleaning them with a scotch-bright pad?

I have had excellent results doing this with my old Yamaha brakes. I used a very light brass brush on a dremel, though.
 
The seal mounting surface is compromised. One path for water intrusion is on this sealing surface. This means you need new calipers.

I now pack a fair amount of silicone grease behind the dust boot, as well as buttering the bore surface with silicone, to give an extra measure of protection from moisture intrusion.
 
You bring up a good point about the contamination on the piston. Perhaps that is the result of the loose dust boot.
AZ has a lifetime reman in stock for 50.00, so no reason not to replace, assuming quality of an AZ rebuilt caliper is OE quality...must be better than what I have now.
I had to replace my AZ passenger side after 5 years. Something happened that caused my inside pad to wear out before the outside pad that has the wear squealer on it.
I am thinking the caliper must have hung up on the mounting bracket or shims somehow, otherwise pad wear should have been even I would think, so not sure if that was a function of lubrication or a caliper failure.
 
Originally Posted by Fitz98
You bring up a good point about the contamination on the piston. Perhaps that is the result of the loose dust boot.
AZ has one in stock for 50.00, so no reason not to replace, assuming quality of an AZ rebuilt caliper is OE quality...must be better than what I have now.

Yes it is due to the loose boot. It's not just to keep dust out of the space.

As has been mentioned I'm sure you could pop out the piston and try cleaning it but on my BMW the rust was far worse making some big pits on the polished surface.
 
You can pull the pistons and try and wipe them clean. But you should not be cleaning them with an abrasive. The piston is plated and if there is rust then some of the plating is gone and it will not seal properly.

Rebuild caliper or replace.
 
Thanks for the feedback. I wasn't considering of the condition of the pistons themselves, you gave me something to evaluate that otherwise would have been overlooked and I ended up replacing the caliper. Not expensive and easy to do, while I had it all apart anyways.
Thanks for the advice.
 
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