How do I remove the rear caliper piston on our 89 xjs?

 

Easiest way I have found to remove pistons is to remove the caliper from the disk leave the brake line connected and then push the pedal this will push the piston out. Do one at a time.

cheers
Warren

 

They are out of the vehicle

 

You need to apply pressure to the brake line, especially if the pistons are tight. Can you attach the calipers to the respective brake lines put a disk in one caliper and then pump the pedal? This might be a PITA as you will need 2 people.

 

Compressed air, about 100+psi, and keep the finger WELL CLEAR, the buggas go off with a BANG.

Being rears, I would split the 2 halves of the caliper, and work on one half at a time. Place the caliper half, piston DOWN, on the bench and apply pressure to the inlet port, and as I said, FINGERS NOWHERE NEAR THAT PISTON. You may have to push the piston back inside first, using a G clamp or similar.

 

Thanks Guys,
Either way is a pain for me. But we can get it done. I'm leaning toward compressed air but need to figure out connections that will allow that kind of pressure.
Just for any other tinkerer out there. I was looking at an expandable internal pipe wrench by the Ridgid tool Co.
Also, I have an expandable mandrel for turning down metal on my lathe.
If I used this I would loose the mandrel and the piston as I would have to drive it into the piston to make it tight. It tighten from the end that would be inside the piston.
I'll get it out though.

Neil

 

I just generally put the pointy end of my OLD brass blow gun in the hole where the brake pipe threaded, and give it a blast, OK, some air will leak back out, but I never had issues that required any special adaptors or such.

Sometimes working the piston in and out is required, but usually it just POPS out, and crud and other niceties sprays everywhere.

 

Thanks guys,
I have really gotten into it yet other than to grab an end that was sticking out with a wrench and see if it turned or not.
When it didn't I guess I went to sit on the extreme side of the fence.
But still it would seem to me that a nice expandable wrench or grooves cut into these things would be great ideas.
JM2CW
Peace
Neil

 

If half caliper is out of the car, pry them out with two opposing screw drivers, using that groove on top of the piston. If you succeed moving it up a little, then lock wise grips onto the top of piston and spin it out.
I just did all that with my rear end being fully redone... fun fun fun!