I received the dash notification that my pads were worn, and I determined that it was the rear ones. I bought some low dust pads and thought that I followed the procedure to release the parking brake. Well, something went wrong. I was for sure able to release the parking brake and get the pads off, but at some point it must have reactivated. Perhaps I should have turned the ignition off, or I ran out of time? The piston extended all the way out and fell out. Now I don't know how to get it back together. It's easy enough to put thread the one part on the screw, but I can't figure out a way to get the boot recaptured. Any suggestions? I've searched the internet and can't find anyone whose encountered this scenario. FYI, my car has a manual transmission if that matters.

 

I believe I’ve read about the exact scenario you describe on this forum. This document includes directions for putting the EPB into maintenance mode.
https://www.dropbox.com/scl/fi/lsrji...csgyoz6wk&dl=0

 

Correct-you need to put it in maintenance mode. Then don't forget to undo it before you drive again.

 

I understand that it needs to be in maintenance mode. It was in maintenance mode and I was able to get the pads off. Unfortunately, it went out of maintenance mode at some point for some unknown reason and barfed out the piston. Now I have to get it all back together again. I need to know if there are any tricks to doing this. Last night I decided that it would be easier if I completely removed the assembly from the car, so I have done that.

 

About to do this procedure myself. Sorry to hear this happened.

Are we supposed to turn the ignition off after initiating maintenance mode?

 

I think that perhaps that's the case. I don't know if my car being a manual factored into the equation either. The easy way to avoid the problem is to unplug the connector to the electronic motor once you get it into maintenance mode.

I have not got to this point yet, but you'll also need a tool to compress the piston. You can't use a C-clamp. Here's what I'm planning on using because I saw someone use it in another video.

 

One other thought - were you on a battery tender during this period? Could having the ignition on for a while have triggered a low voltage state and reversed maintenance mode?

That tool looks good - does the piston rotate as it retracts?

 

My car wasn't connected to a battery tender.

The piston itself doesn't rotate, but it travels down a spiral shaft.

 

You need to remove the motor off the caliper and you'll see a place to crank the spindle with an allen key or torx...can't remember. Be careful the screws to remove the motor are tight and relatively easy to strip.

 

Don't think that tool will work?
It just pushes straight in same as the old C-Clamp method and I have always had to rotate while pushing the caliper piston back in?

I use the surprisingly nice Harbor Freight kit. About $45.

Disc Brake Caliper Tool



I was surprised that at least one of the adapters did fit Jaguar.
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I don't know. In the video below, it didn't rotate (externally).

 

Some thoughts:

• First recharge your battery with a CTEK or other charger / maintainer. I think a low voltage state reversed maintenance mode and pushed the piston out.
• Once fully charged I would keep it connected to the CTEK and put your brakes back into maintenance mode (your EPB motor currently thinks its fully extended in parking mode based on the piston having been pushed out).
• Then screw the thrust nut fully on until it stops and push the piston as far as it will go. The thrust nut locks into the piston so you may have to turn it until it seats (see below - thanks for the guide, DJS).
• The car performs an automatic brake pad clearance adjustment after you finish installing the new pads and exit maintenance mode.
• I haven't done this DIY on the Jag so hopefully someone else can chime in if this seems reasonable.

 

Sorry I was posting about turning the EB caliper in. Your right now it looks to be automatic?
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