Rear Brake master cylinder rebuild - Piston seized

[Narcissus]

I'd like to rebuild my rear master cylinder, but the piston (part inside before the spring) is seized to the body. I've tried blowing it out with compressed air to no avail.

Anyone have suggestions on removing the piston without damaging the shaft inside?


I had ordered a knockoff that was supposed to fit, but the mount bolt holes are too large and too far apart to fit without significant modification. Next best option right now is refurbishing the master cylinder with a rebuild kit.

 

[sixpack577]

Soak it with or in penatrating oil.
A little heat on the caliper(not glowing either).
Whack it with a plastic or brass hammer.
And if it comes out, hopefully it's not rusted and corroded beyond being rebuilt.

EDIT
Sorry, I tre read that, and thought you had a piston frozen in the caliper,
But, the same things will work on the rear MC.

 

[Narcissus]

Not much luck. I think it's fairly stuck in there and even if I get it out, it'll probably have eroded a ring in the cylinder. Tried boring the piston out, but it's still stuck. Probably better to cut my losses and find a replacement.

 

[jeffgordons24]

Not much luck. I think it's fairly stuck in there and even if I get it out, it'll probably have eroded a ring in the cylinder. Tried boring the piston out, but it's still stuck. Probably better to cut my losses and find a replacement.

Gen 1 or gen 2?

 

[jeffgordons24]

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/362528047875

 

[Narcissus]

That'll work! Thanks for the find!

It's a '99 - gen 1

 

[Narcissus]

Quick question, will the gen 2 fit the gen 1? They look identical from the pictures with slightly different part numbers.

There is a nicer looking one for a '13~15 on there.

 

[Narcissus]

After comparing photos of the two, I'm pretty sure both parts are identical. Went out on a limb and ordered the newer one (couple bucks cheaper, to boot).

Slowly getting the bike pieced together. Hoping I don't run into any more surprises.

 

[jeffgordons24]

After comparing photos of the two, I'm pretty sure both parts are identical. Went out on a limb and ordered the newer one (couple bucks cheaper, to boot).

Slowly getting the bike pieced together. Hoping I don't run into any more surprises.

I’m sorry I missed your other post with the question!
Awesome let us know if it fits and snap some pics.

 

[Narcissus]

No worries.

I remember a lot of parts were interchangeable between Suzuki and Kawasaki. It's nice to see they're still using the same parts from 20+ year old models.

It's been a slow process without time to work on the bike. Haven't ridden the bike in over five years, so I'm looking forward to getting it on the road again.

 

[Kiwi Rider]

No worries.

I remember a lot of parts were interchangeable between Suzuki and Kawasaki. It's nice to see they're still using the same parts from 20+ year old models.

It's been a slow process without time to work on the bike. Haven't ridden the bike in over five years, so I'm looking forward to getting it on the road again.

FIVE YEARS!!!
What happened? Ya had a marriage and divorce??
That's way too long to let a Busa sit around for, no wonder the MC is seized. . . . let us know how you go with the resurrection

 

[Narcissus]

Just marriage... and I was gone in Korea several years (rode when I came back to visit, but made the mistake of not draining the tank/fluids before I left).

Moved back two years ago, but they were spent finishing renovations on the house I left here. Finally getting time to do things.

 

[Narcissus]

I made the mistake of buying a "new" cylinder from a third-party seller off walmart. Returned it and dealing with them to get my money back over the inaccurate listing that borders false advertising. It's only a few bucks for 'restocking', but I'm more than willing to fight over the principle so other third party sellers don't pull this scam (pretty sure they just copy-pasted a list of Suzuki models and said it would fit them all).

I got the 2013~2015 master cylinder off eBay from the same seller and it's identical in almost every way. Saved a few bucks and it's genuine OEM, so I'm happy. Will put it back together, flush the system and get the tail section back together.

I just have some electrical connections to re-do in the front end, re do the airbox (foam has completely disintegrated from age), some other details and I should be able to test.... oh, and getting a new battery, preferably genuine Yuasa. I'm done with knockoff Chinese B.S.