"splitting" the calipers on a xj550

Hi, If I want to separate the two parts that is the caliper, is it just to slide out the pin that holds them together?

I tried it gently but the rubber covers thats on there seems to be holding the pin in and didn't want to destroy anything. But looking at some diagrams there seems to be nothing else there.. so.. More force?

 

You probably have some corrosion, or dirt buildup on the pin. Try soaking it with Kroil, or PBblaster. To much force could damage the guide holes.

Ghost

 

Well, I actually can get it to move a bit, but then it bounces back. maybe the rubber has bonded slightly with the pin?

 

The penetrating oil should help break that bond if that is the case.

BigFitz I am sure will have a better idea when he pops in later. When it comes to the 550's. He is the man to talk to.

Just to make sure that we are talking the same thing. You are trying to pull the pin that attaches the mounting bracket to the caliper. Correct?

Ghost

 

Correctomundo!

 

More force.

In a lot of cases, the "sliding pin" has become a "beat it with a big hammer pin." I recommend replacement; the pin is still available and any sanding/polishing of the original to remove corrosion or pitting, etc., will only serve to make it too loose upon reassembly.

The caliper should slide freely along the pin/against the surface of the holding block and shim plates; without "hanging from" the pin, or excessive looseness. What usually happens is the boots fail and the pin becomes corroded into the holding block. When the caliper is no longer free to slide in relation to the holding block, the brake starts to drag.

A corrected version of the parts diagram from the fiche is below. Chacal has pin boots available (Yamaha never even put a part number on them.)

 

Thank you bf!

I suspected that much, but didn't want to risk it
Next up, is to touch up the caliper body with some new paint and then replace the seals around the piston.

 

The key to that is to get the channels that the seals go in completely clean without doing any damage. I use a tiny brass wire brush in my Dremel, plus sharpened bamboo barbeque skewers. You can break up stubborn deposits by lightly "kissing" them with the flame from a propane torch. Be careful not to overdo it.

Examine the piston for signs of damage or pitting. Some pitting is OK, as long as it's not in the area "swept" by the seals. Polish the piston using synthetic abrasive pads (Scotchbrite,) not steel wool or sandpaper.

*IMPORTANT* When re-assembling, be sure to put the pad anti-rattle spring in place in the caliper before installing the piston. You cannot get the anti-rattle spring into place with the piston installed. (Guess how I learned this.)

 

The pistons are clean on the outside (that is on the surfaces that touches the seals), inside the piston cup there is rust, as to be expected since it's a perfect place for collecting moisture. But still, nothing damaging to the structure.

Overall the calipers seem to be in good condition, there was some residue on the inside, but nothing that a ordinary rag wouldn't get rid off with some elbow grease. The main seal looked like it would have worked a couple of miles more, but the dust seal didn't look good at all.


Are you real sure about the anti-rattle spring? I managed to get it out if i compressed the piston all the way in, figured if it comes out it has to come back in while in the same position. But yes, getting it in to place before is probably easier anyway