Caliper Seal Kit pn 1J3-W0047-00 what's this, seal grease?

[pjc]

I bought a Yamaha brake caliper seal kit from PartZilla. In the kit is a small plastic sealed bag with what looks like lube of some sort. Anyone know what this is for? Normal practice is to wet all parts with brake fluid for assembly.

BTW, I wound up having to order a new piston as the old one had substantial pitting under the caliper seal area. Old seal was damaged, and one area sort of rolled over, distorted. I can't believe the caliper didn't leak more brake fluid than it did.This is for an '80SG.

Thanks in advance, Pat

 

[Mailman]

If I had to venture a guess, I’d say it was a little silicone just for wiping on the seal.

 

[5twins]

It might be anti-squeal lube too. You place it on the back of the pads where they contact the piston and the caliper. And speaking of the piston, you see how corroded up the outside part can get. I'll bet the hollow inside portion is pretty rusty too. I smear all that with a light coating of rubber friendly red rubber grease.

 

[pjc]

Thanks for the replies Gents. Yes, the inside hollow is rusty. I'll be sure to coat the inside and so forth when I reassemble the piston.

How I got here was installing a new master. When bleeding I kept getting bubbles when I shouldn't be. I figured I was pulling air past the caliper seal. I took a break, gave the brake lever a healthy squeeze, went in house. Came back half hour later, found a brake fluid puddle on floor. Well, done with that for now, order seal kit.

Decided to tackle fork seals. Got that done. Caliper seal kit was delivered, hope and pray that piston was serviceable. Nope. Order piston today, and here I am waiting for delivery.

I found a discussion here, https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3341133/Brake_fluid,_or_grease,_on_cal , regarding a lube for the seals. One quote is:
"On the seals themselves. I have in the past used a little pack of grease that has come with a new set of seal (Girling used to always enclose this and instruct you to use it. I never liked the idea of getting brake fluid anywhere other than where it needed to go." end quote.

Another thread about caliper piston seal grease: https://www.ferrarichat.com/forum/threads/brake-cylinder-paste-source.410361/ .

Could be the grease in the sealed bag is for the piston seal.

 

[5twins]

I read about that red rubber grease here on the forum from our English members. It's vegetable oil-based grease made special for rubber. I had to send all the way off to England for a tub but I'm glad I did, it's wonderful stuff. It's great on all the rubber brake components but also on just about any other rubber item you'd like to lube. It works great on the footpeg mount rubbers, allowing them to slide on and off their mounting studs easily, even after they've been installed a while. I always found them stuck on there whenever I'd go to remove them.