Master cylinder/caliper cleaner

crackerman

crackerman

Been Around the Block
I'm looking to clean out my master cylinder and calipers on my front and rear brakes. I'll be putting new lines on, but I want to clean out the calipers and master cylinders really well. I've broken them down to the point I can soak them.

Can I throw them in some carburetor dip and let them soak over night? What have you guys been soaking them in to clean them out?

Thanks
 
Just fresh brake fluid. Its all I ever use.
I use a pick to scrape off old crusty fluid with the exception of inside the piston bore. I never put any abrasives in there, just a clean rag and fresh brake fluid.
 
crackerman said:
Can I throw them in some carburetor dip and let them soak over night?
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Yeah, that's the ticket. That will effectively ruin every rubber part so that then you can finish taking them all apart and rebuild them. ;)

Seriously, don't soak them in anything. Brake fluid and petroleum solvents are not compatible with one another. You can use some non-chlorinated brake cleaner spray. Don't use the chlorinated type. Not only is it really dangerous and extremely toxic to have around the shop, it almost instantly ruins any rubber part it comes into contact with.

Remove the piston from the caliper. Clean out the bore with a rag. If there is corrosion in the O-ring groove, remove the O-ring and clean the groove. I have reused the O-ring and any other seal or boot when I had to, but the best thing is to replace all the rubber parts. They don't cost that much. DO NOT lubricate the piston with brake fluid when you put it back together. Brake fluid on the outside of the seal will attract moisture, and cause corrosion. Use Permatex Ultra brake and caliper lube.

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_x_7730004-P_x_x?cm_mmc=ACQ-_-Google-_-GPLA-_-7730004&ci_src=17588969&ci_sku=7730004&ci_gpa=pla&ci_kw=&gclid=CNeI1OGd5LoCFWdnOgodqV0AJQ#utm_source=acq&utm_medium=google&utm_campaign=gpla&utm_content=7730004

Coat the inside of the caliper bore with a light film of it, and put some in the seal groove before installing the seal. Lightly coat the piston, and insert it.

Master cylinder is a little trickier to take apart. You need a snap ring pliers that is just the right tool to get the snap ring out. Also, the dust boot around the master cylinder piston rod rarely tolerates removal without being destroyed. If the master cylinder was working OK, just flush it out with brake fluid and hope for the best. I have seen master cylinders that were loaded with crud that were still working just fine. Whenever possible, I try to get a rebuild kit for them and rebuild them, but I am a master mechanic, and don't get frustrated with the difficulty of getting that fucking snap ring out.
 
AlphaDogChoppers said:
don't get frustrated with the difficulty of getting that fucking snap ring out.
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I'm good until BOTH eyelets bust of the damn thing then I'm PISSED!..

Save your $5 and don't buy the "blue label special" snap ring pliers either at the local auto parts store. They're likely to not work for that anyways. Buy a better pair or set with a longer nose.
 
Ah, the joys of working on neglected vintage bikes.

I never had that happen to me with a master cylinder, but I have had it happen with a fork seal snap ring. It was pretty much unrecoverable.
 
The amazing dremel and the cylindrical steel cutting bit works wonders at that point.. Still sucks, but works... I think the metal circlips are made of adamantium. ;)
 
I went with the hot water mixed with degreaser/simply green mix. Let it sit for a few hours, scrubbed, rinsed and then air compressor dried. The rubber looks pretty decent from the calipers and there's only a couple of small nicks on the front piston. Rear pistons look good. Not sure how these brake even worked as the pistons where in there pretty good. I used the air compress method and they shot out like a cannon after many attempts. The rear master cylinder will clean up nicely but the front is too far gone and I think I'm just going to get a replacement. I found another thread that said to use brake assembly fluid to put everything back together. Plan is to paint the calipers before re assembly.


Front caliper

Rear caliper

Rear caliper

Front piston

Front master cylinder
 
I've made far far worse look brand new again. Don't throw away anything, I always keep everything... If you're going to pitch it out, let me pay you to ship it to me and I'll put it to good use, other than trash.

I would not paint any brake parts. Brake fluid eats paint away in a matter of seconds, especially rattle can... Just polish, blast, or powder coat. Anything else and you'll have headaches later and will be redoing it.

That one caliper piston with pitting will leak for sure. They sell stainless steel replacements that will be better and won't leak. I think most of them are around $30 or so. I would definitely replace that.
 
mark13018 said:
That one caliper piston with pitting will leak for sure. They sell stainless steel replacements that will be better and won't leak. I think most of them are around $30 or so. I would definitely replace that.
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I would use it. Buff it up with a polishing wheel. The pit is smaller than the width of the piston seal, but replacing it would be desirable if an easy replacement is available, but if I had to, I would use it.
 
AlphaDogChoppers said:
I would use it. Buff it up with a polishing wheel. The pit is smaller than the width of the piston seal, but replacing it would be desirable if an easy replacement is available, but if I had to, I would use it.
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I've been looking for a replacement piston and can't seem to find one. The pits aren't really that bad. I think it will be ok.

Looking into powdercoating but I want to keep my budget low on this one. I agree that the paint will flake once the brake fluid touches it.
 
Just FYI... HVC cycle is awesome for things like this. Bought some long OOP (NLA) pistons for a XJ1100 from them. Worked perfect.

According to the parts list the OEM Kaw part number is 43048-006 for the piston and the HVC site shows it will fit your bike for front and rear.

http://www.hvccycle.net/kawasaki-brake-caliper-piston-replacement-for-kawasaki-part-number-43048-006/
 
mark13018 said:
Just FYI... HVC cycle is awesome for things like this. Bought some long OOP (NLA) pistons for a XJ1100 from them. Worked perfect.

According to the parts list the OEM Kaw part number is 43048-006 for the piston and the HVC site shows it will fit your bike for front and rear.



http://www.hvccycle.net/kawasaki-brake-caliper-piston-replacement-for-kawasaki-part-number-43048-006/
Click to expand...

Thanks for the link Mark

That def looks like the right piston.
 
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