Why you need to rebuild your caliper and M/C w/pics

So if you haven't gone down this worm hole. Here is some motivation as to why you should. Granted this Master Cylinder and Caliper were not the worst offenders that I have ever seen. These were parts that the Previous Owner rode daily and for about a month so did I. The whole time I was working on the brakes, The question in my mind was. How did this thing stop?

First was to start with the caliper. Taking off the dust seal revealed that it was badly cracked. Although unfortunately in all my tries I could not get the picture to show it. But you can see the buildup of Brake fluid gunk on the inside of the seal, indicating that the Main seal was not sealing well as well.



Also the main seal



The "Gunk" in the Caliper was this lovely mess. Per RickCoMatic this is the result of water mixing with Brake fluid.




So needless to say that all got rebuilt. Need I say more?

So on to the Master Cylinder.

Taking off the cover showed the seal is in sorry shape.



Initial inspection of the piston showed something really wrong.



In case you were wondering it is completely split in two.

Further into the worm hole.



The lovely mess that happens once the seal is broken. Do you really want all this getting into your brake fluid when you want to stop?



What was left of the seal once it was torn free.



The piston as it came out.

And the piston, circlip and spring after they had been dried off.



And finally the mess inside the MC





Now like I said before. These are not the worst offenders out there and many on the forum probably have evidence of worse. But the fact still remains that had it not been for this forum I would have never thought to check this. And imagine what the result would have been in a panic stop?

Check your brakes.

 

That's pure ugliness! Thanks for sharing!

 

Folsoml,
Yeah, I almost threw up, lol!

Osprey,
Seriously, your pictures clearly SHOW more than any words why it is so important to rebuild those parts.

 

Great pictures to show how bad things were, and you're RIGHT, it's something you can't actually see the severity of until you actually tear into it.

Good stuff.

 

Excellent, thank you. That M/C is a classic case...

 

Thank god mine weren't THAT bad when I did them a few years ago lol.

 

Nice job

 

Really nice job, thanks for sharing that. It's next on my list of things to do and this helps!

So you were able to reuse the MC piston no problem?

How did you clean that MC? Did you just spray it with brake cleaner once you had it all apart? And that cover seal, mine looks like that. Rebuild kits don't come with those, how did you fix that up?

Jim

 

Thanks,

To clean the mc I stripped all the parts off it and put it In carb dip for a couple of days. After taking it out then I hit it with brake cleaner and all new parts. I did not even try to reuse the old piston as the rebuild kit I got from len had one in it and also I figured since my life depends on this I might as well replace it. Yes the cover diaphragm is not part of a standard rebuild kit. I got a replacement through Len at xj4ever.

If you are gonna tackle the mc you might as well do your caliper and replace your lines in the process. It is super easy as many can attest to and the difference is night and day. Just something to keep in mind.

Good luck and any questions don't hesitate to ask. Plenty of good help here as I'm sure you've figured out.

 

Thanks,

To clean the mc I stripped all the parts off it and put it In carb dip for a couple of days. After taking it out then I hit it with brake cleaner and all new parts. I did not even try to reuse the old piston as the rebuild kit I got from len had one in it and also I figured since my life depends on this I might as well replace it. Yes the cover diaphragm is not part of a standard rebuild kit. I got a replacement through Len at xj4ever.

If you are gonna tackle the mc you might as well do your caliper and replace your lines in the process. It is super easy as many can attest to and the difference is night and day. Just something to keep in mind.

Good luck and any questions don't hesitate to ask. Plenty of good help here as I'm sure you've figured out.

 

Thanks a lot for the reply. Yep, I actually have my SS lines and new pads that I was going to install this weekend, but Fitz talked me out of it. Said to rebuild the MC and caliper too as doing the bleed in stages is a real PITA lol.

 

How did you get that MC Circlip out?

I would venture to say that the Front Brakes are close to, if not, at the top of the list for most neglected system requiring routine maintenance.

I'll bet there are hundreds still relying on OEM Master, Lines and Caliper Seals.

Nice pictorial.

 

Tim, I would definately agree, if your going to be swapping the lines anyway, might as well do everything while your at it. That way you wont have to worry about it for quite some time.

Rick, Let's just say that there were a lot of obsinities that can not and should not be repeated here on the forum. A lot of asking for the almighty's assistance in sending the cursed thing straght to the underworld if you catch my drift. Eventually it was just a process of slowly scratching off all the sh... er um, gunk... off of it, blow out the loose stuff and scratch some more till I could get the cir-clip pliers to bite the holes enough to break it loose.

 

When I bought my bike, the front brakes were seized. So luckily, I HAD to rebuild them before I could even easily drag it about the yard none the less fly down the road.

 

Once I get back home I'll have to put up a picture of the disgusting mess I found in my master cylinder when I finally cracked it open. Gelled goop

 

I have use my ultra sonic cleaner to clean the MC after disassembly then replace the seals and put it back on.

 

Pics are worth a thousand words...thanks for posting!

 

This is what I am worried about! Adding it to the list of things to be done before going on the road! thanks for the share!

 

Any advice on where to find a good MC or caliper rebuild kit?

 

Click on the banner in the top-right corner of the page. Len at XJ4Ever can get you everything you need.