caliper pots sticking

KwackerJack

I rebuilt the calipers on my 97 xj900 diversion.

The pots will move out but not back in so the brakes are nit stuck on but make it very hard to free wheel the bike. I rebuilt them again and it's the same issue!

I used spurious seals and was wondering of this is the cause?

Caliper and pots were cleaned meticulously!

minidazzler

Stupid question, I know, but did you Coat the seals in brake fluid? Sometimes the silly stuff catches us...

Skill Magill

Probably be shot down for suggesting this, this used to happen to me when I was a courier, I just removed the seals altogether!

cantdecide

Was there much in the way of pitting on the piston after cleaning? Did you have to use any sandpaper etc?

KwackerJack

Yes coated them I'm fresh fluid.

Took out the seals?

Small putting but not major, used wet and dry just to smooth them down.

I've rebuilt a lot a calipers over the years on my bike but I've thankfully never into now had this issue on newly rebuilt calipers!

CJhaughey

Sounds like seals are not the same dimensions.
I have found with brake parts original is usually best, the quality control on spurious parts may be fine on less critical stuff but for brakes OEM stuff is best.
This is through bitter experience with a good few MC rebuilds and 5 caliper rebuilds.
Just one thing to check, the little square channels that hold the seals were cleaned back to clean metal? These can build up a film of crystalline brake fluid and cause the seals to press on the pistons a little too hard.
Also red rubber grease is the best stuff for lubing rubber brake parts, its not that expensive but a little hard to source in Ireland.
Opie oils sell a 500g pot of it for around 8 stg.

KwackerJack

I did thoroughly clean where the seals sit in.....I will take them apart again this weekend and see if I can notice anything out of place.

Yamaha have the seals for 45 so I'll order them as soon as I know theer is not another issue.

CJhaughey

I have found when cleaning calipers that if you wash them out with water, and dry them with a blowtorch carefully so you don't melt or burn other rubber components that the gritty crap in the caliper dries out well and can be cleaned easier than if you try and do it wet with brake fluid.
Once dry the stuff turns to powder and can be picked out easily.
Then when you rebuild them a quick blast of brake cleaner and let them dry.