2 XJ550 Caliper Questions

I have not had a problem to date with my front brakes. I decided to replace the pads and when I removed the caliper, the piston will not move. I did some forum searching and concluded that my caliper was frozen and then searched ebay for a replacement caliper. I found a complete working system from an 82 xj550: caliper, lines, joint, mc and lever for $40. The seller informed me that the system worked flawlessly before removal.

So here's question 1: When I got the brakes out of the box tonight with the intention of swapping the caliper, I noticed that the caliper I received was an exact mirror image of the caliper I have and is stamped with an "R" Gasp! There was only that one caliper and the MC did not have anything on it that would suggest a dual caliper system. My 550 max has a single caliper on the left and the 550 brake system I received is for a single caliper on the right. I thought all xj550 max's had a single left and secas had dual... What '82 XJ550 had only a single rhs caliper?

Question 2: I figured I'd inspect it anyway and found that the piston on this caliper does not "move freely" as the Clymer manual says it should. Is this caliper frozen as well or am I not doing something right? I only ask because this is now the second caliper that "worked fine before removing" and now I cannot move the piston.

Please help! This is the only issue left on my xj that's keeping me from riding and it's finally riding weather in Delaware! Thanks.

 

the pistons are hard to move by hand, you would need to use something like 2 strong screwdrivers opposed to each other as levers.

 

The caliper you received is from a 550 Seca, which is mounted on the fork tube.......also a single-disc bike (here in North America). Won't work on your bike..........

 

chacal is right; you got a 550 Seca setup.

Wiz, there's nothing to pry on, the piston is dead smooth.

Regardless, a 25+ year old caliper should be rebuilt, whether it came off eBay or off your bike, it's still OLD. There's nothing more in there than 2 rubber rings; and after all this time they need to be replaced, plain and simple.

Removing the stuck piston is easy: the bleed screw is the same as a grease nipple. Replace the banjo bolt with a regular bolt, open the bleed screw, pop on your grease gun, and start pumping. A bit messy but the piston will come out.

The most difficult part of the job is getting the grooves inside the caliper surgically clean (without tearing them up) before fitting new seals.

 

Thanks for the tips and info everyone!

fitz, after removing the piston with your grease gun trick, how does one get the grease out of the inside of the caliper? is it easy? although I have not seen the inside of the caliper, I am envisioning nooks & crannies, chambers & such...

 

Try some brake cleaner,it removes all grease and leaves no residue,also it evaporates quickly.

 

thanks for the tip, BlackMax.

Good news update: the ebay seller agreed to take the brake system back with a full refund!

 

Fitz, I was saying you can get it to move inwards, by levering against the opposite side of the calliper, not lever it out.
Porter, I put a piece of wood where the rotor would be, so the piston doesn't go into orbit & put the air line in where the fluid line goes, no mess, no fuss, etc.

 

Wiz; oops, sorry I thought you meant to get it out.

I've never been able to get air to work, even at 125PSI. The grease gun trick works every time and is only messy, not dangerous.

No nooks, crannies, chambers. Just a big round hole with two grooves near the top and holes in the bottom side where the bleed and banjo bolts go.