KZR's Bikes of the Month for 2024

1984 GPZ550 rear brake stuck

More
18 Jun 2020 11:58 #828392 by dpivas7
1984 GPZ550 rear brake stuck was created by dpivas7
The rear brake on this 1984 GPz550 I am working on is stuck. when you press on the brake lever, the lever doesn't return, even though the spring is still attached to the mechanism. The reservoir is filled with fluid to the correct level.

Does it need a simple brake bleed or is there something wrong with the caliper?
Current: '19 Harley Roadster, '72 XLCH, '84 GPz 550
Past: '84 GPz 550, '82 KZ750 LTD, '71 XLCH

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

  • Scirocco
  • Offline
  • Premium Member
  • Never change a running system
More
18 Jun 2020 12:36 #828398 by Scirocco
Replied by Scirocco on topic 1984 GPZ550 rear brake stuck
Looks more like an rear MC and caliper clean and rebuild Job.
My 1975 Z 1 B 900 Project

www.kzrider.com/forum/11-projects/605133...ears-deep-sleep-mode

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

  • TexasKZ
  • Away
  • Platinum Member
More
18 Jun 2020 13:27 #828402 by TexasKZ
Replied by TexasKZ on topic 1984 GPZ550 rear brake stuck
Could be the brake lever pivot. It is one of those oft neglected maintenance items. Water and dirt can build up, causing rust on the pivot shaft.
1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough

www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
The following user(s) said Thank You: Nessism

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

More
18 Jun 2020 13:41 #828404 by dpivas7
Replied by dpivas7 on topic 1984 GPZ550 rear brake stuck
The brake stays locked, even if I pull the lever up
Current: '19 Harley Roadster, '72 XLCH, '84 GPz 550
Past: '84 GPz 550, '82 KZ750 LTD, '71 XLCH

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

  • TexasKZ
  • Away
  • Platinum Member
More
18 Jun 2020 14:09 - 18 Jun 2020 14:11 #828406 by TexasKZ
Replied by TexasKZ on topic 1984 GPZ550 rear brake stuck
Then it seems a full hydraulic rebuild is in order, though I would still pull the lever off to clean and grease the pivot. Be sure to carefully clean the seal groves in the caliper.
1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough

www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
Last edit: 18 Jun 2020 14:11 by TexasKZ.
The following user(s) said Thank You: dpivas7

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

More
18 Jun 2020 14:43 #828411 by dpivas7
Replied by dpivas7 on topic 1984 GPZ550 rear brake stuck
Ahh okay! Would it be sufficient to buy a caliper rebuild kit?
Current: '19 Harley Roadster, '72 XLCH, '84 GPz 550
Past: '84 GPz 550, '82 KZ750 LTD, '71 XLCH

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

  • ThatGPzGuy
  • Offline
  • Sustaining Member
  • More Sparky than Speed Racer
More
18 Jun 2020 15:48 #828416 by ThatGPzGuy
Replied by ThatGPzGuy on topic 1984 GPZ550 rear brake stuck
This just happened to me on my XS650. You'll need to pull the MC and rebuild it. I would suggest honing as well since the piston is probably seized in the bore.. Try that first and then, if needed, rebuild the caliper.
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"

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

More
18 Jun 2020 16:01 #828417 by Nessism
Replied by Nessism on topic 1984 GPZ550 rear brake stuck
Motorcycle master cylinders should not be honed. Pull it apart and inspect for pitting in the aluminum. If it's okay install an OEM piston kit and replace the brake line. Same goes for the caliper, only instead of worrying about the bore look at the pistons.
Ed
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0

www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know

1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread

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

More
19 Jun 2020 12:52 #828476 by ned37
Replied by ned37 on topic 1984 GPZ550 rear brake stuck
sounds like the small return bleed hole in the mc is plugged, keeping the pressurized fluid from returning from the caliper
'83 GPZ1100, '97 Triumph Trophy 1200, '08 Husky TE610
Verde Valley, AZ

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

More
28 Jun 2020 12:11 #829216 by dpivas7
Replied by dpivas7 on topic 1984 GPZ550 rear brake stuck
I don't see a bleed hole anywhere.
Current: '19 Harley Roadster, '72 XLCH, '84 GPz 550
Past: '84 GPz 550, '82 KZ750 LTD, '71 XLCH

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

More
28 Jun 2020 14:32 #829226 by dpivas7
Replied by dpivas7 on topic 1984 GPZ550 rear brake stuck

Nessism wrote: Motorcycle master cylinders should not be honed. Pull it apart and inspect for pitting in the aluminum. If it's okay install an OEM piston kit and replace the brake line. Same goes for the caliper, only instead of worrying about the bore look at the pistons.


I can't find any rebuild kits for a 1984 GPz550. Would a 1982-1983 rebuild kit work? The manual says "The rear master cylinder on ZX550-A1 and A2 models has changed slightly from other models" so I don't know if a 1983 would work.

Also can't find any complete rear master cylinders for less than $300
Current: '19 Harley Roadster, '72 XLCH, '84 GPz 550
Past: '84 GPz 550, '82 KZ750 LTD, '71 XLCH

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

More
28 Jun 2020 15:18 #829242 by Mikaw
Replied by Mikaw on topic 1984 GPZ550 rear brake stuck
This is the tiny hole that allows pressure to be released and allows the caliper to back off a smidge and not drag

1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.
Attachments:

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.