KZR's Bikes of the Month for 2024

process for removing piston from master cylinder

More
31 Jul 2021 14:12 #852916 by Lord Osis
I have a used rear MC for my 82 GPz550 that appears to be working, but it is full of gunk so I thought I would clean it up a bit
I also located a NOS piston and was debating replacing the old one, although if it aint broke, don't fix it is my philosophy with old vehicles
Is there a way other than using compressed air to remove the piston?
I am also wondering I were to use compressed air, what do I do with the bleed holes, just hope the pressure is enough with them open, or try to close them in some way?

Please Log in or Create an account to join the conversation.

  • Scirocco
  • Offline
  • Premium Member
  • Never change a running system
More
31 Jul 2021 15:53 #852921 by Scirocco
Did you remove the c-shaped wire clip (retainer)?

 
 
 

Please Log in or Create an account to join the conversation.

  • ThatGPzGuy
  • Offline
  • Sustaining Member
  • More Sparky than Speed Racer
More
01 Aug 2021 07:58 #852943 by ThatGPzGuy
Replied by ThatGPzGuy on topic process for removing piston from master cylinder
I've never done it but I have heard of others using a grease gun to force a caliper piston out. I've never had a MC piston get stuck. 

Jim
North GA
2016 Yamaha FJR1300ES
1982 GPz750 R1
1974 Kawasaki H1
1976 Kawasaki KZ400
1979 Yamaha XS650 cafe'
2001 KZ1000P
2001 Yamaha YZ426
1981 Honda XR200 stroked in an '89 CR125 chassis
1965 Mustang
1967 Triumph GT6
1976 Bronco
"If you didn't build it, it's not really yours"
The following user(s) said Thank You: Lord Osis

Please Log in or Create an account to join the conversation.

  • slayer61
  • Offline
  • User
  • KZR FLAG RELAY CARRIER #62
More
04 Aug 2021 09:43 #853142 by slayer61
I've had to use compressed air to get pistons out of calipers. Keep your fingers out of the way. 

Don't be ridiculous! It's only a flesh wound!

[strike]Wife's little bike... 1984 GPZ 550 Kerker and DynaJet stage I kit[/strike]
Wife's BIG bike......[strike] 1981 GPZ 1100 Kerker and [strike]factory FI[/strike] Mikuni RS34s W/ K&N pods[/strike] SOLD

Please Log in or Create an account to join the conversation.

  • hardrockminer
  • Offline
  • Sustaining Member
More
04 Aug 2021 15:03 #853161 by hardrockminer
Replied by hardrockminer on topic process for removing piston from master cylinder
Grease gun!  Compressed air contains a lot of energy...enough to hurt someone when the piston comes flying out.  Grease is virtually incompressible so you don't need to worry about flying bombs.

I have several restored bikes along with a 2006 Goldwing with a sidecar. My wife has a 2019 Suzuki DR 650 for on and off road.

Please Log in or Create an account to join the conversation.

More
04 Aug 2021 21:59 #853182 by cb900f
They should pop out on their own once the C-clip is removed.  There may be some crud on the barrel which is preventing the piston from coming out - clean it up as best as you can.  You could try 'cooking' in boiling water for a few minutes to loosen things up.

Please Log in or Create an account to join the conversation.

Powered by Kunena Forum

If you like KZR Please consider making a donation. Thank you.

KZRider is free, but not without cost.

Please consider chipping in a few bucks to help cover the cost of running the KZR servers.