Author Topic: Leak:Final Drive seal or Brake Piston?  (Read 5373 times)

Offline Farmrjohn

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Leak:Final Drive seal or Brake Piston?
« on: August 26, 2017, 05:01:37 PM »
94 K75, 57.5K miles.  After 10 days or so was going to ride but found a fluid leak on the garage floor, rear wheel, tire, and inboard side of the brake rotor.  All exposed surfaces of the final drive are dry.  The fluid feels slippery but does not really smell like gear oil.  Searched here and on google and have eliminated the speedo drive O-ring as a possible cause (dry, but had been removed 1K miles ago for a tire change/spline lube). Looking up at the anti-skid sensor there appears to be a drop of fluid on it.  Running paper toweling under and around the brake caliper comes out dusty but dry.  Bike has been on the center stand.  If I move the bike from the garage to my shop area, do I need to worry about contaminating the disc pads with oil.  Do I need to worry about them already being contaminated?  The last time I rode the brakes seemed fine, and there were no anti-skid failure lights.
  • Cali. Coast 93441
  • '94 K75

Offline johnny

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Re: Leak:Final Drive seal or Brake Piston?
« Reply #1 on: August 26, 2017, 05:06:32 PM »
greetings...

more than one dog has give back to my brick what mother earth gave to the dog...


* thisisnotdoggpiss.png (353.82 kB . 449x369 - viewed 339 times)

j o
  • :johnny i parks my 96 eleven hundert rs motobrick in dodge county cheezconsin  :johnny

Offline Martin

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Re: Leak:Final Drive seal or Brake Piston?
« Reply #2 on: August 26, 2017, 05:35:07 PM »
Clean and dry thoroughly then spray the suspect areas with spray talc, do not spray the disc. Go for a ride and take a look the leak should show. The other method is the taste test, not recommended if you suspect the dog. Taste the leak then compare with the taste of brake fluid, final drive oil, and dog pee.
Regards Martin.
  • North Lakes Queensland Australia
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Offline The Mighty Gryphon

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Re: Leak:Final Drive seal or Brake Piston?
« Reply #3 on: August 26, 2017, 09:16:24 PM »
Blown shock.  Been there.
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
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Offline Laitch

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Re: Leak:Final Drive seal or Brake Piston?
« Reply #4 on: August 26, 2017, 11:21:28 PM »
If I move the bike from the garage to my shop area, do I need to worry about contaminating the disc pads with oil.  Do I need to worry about them already being contaminated? 
¿Si tus problemas tienen soluciones, porque te preocúpas y si tus problemas no tienen soluciones, porque te preocúpas?

A worry-prone person might chose from these transport preparation options:
  • Disconnect the rear caliper from its mount, remove it from the rotor then hang it by a bungi cord from a pillion grab handle.
  • Find the source of the leak then put a rag around it so it doesn't leak more.
  • Transport the bike to the shop by helicopter or furniture dolly.
  • Solicit volunteers to move the bike coffin-carry style.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline Farmrjohn

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Re: Leak:Final Drive seal or Brake Piston?
« Reply #5 on: August 27, 2017, 03:41:08 PM »
Clean and dry thoroughly then spray the suspect areas with spray talc, do not spray the disc. Go for a ride and take a look the leak should show. The other method is the taste test, not recommended if you suspect the dog. Taste the leak then compare with the taste of brake fluid, final drive oil, and dog pee.
Regards Martin.
No worries on suspecting the dog, the bike has been parked in a closed garage. 


Blown shock.  Been there.
All parts of the shock are dry and no signs of leaking around the final drive mounting bolt.  Are there other visual indicators of a blown shock?

¿Si tus problemas tienen soluciones, porque te preocúpas y si tus problemas no tienen soluciones, porque te preocúpas?

A worry-prone person might chose from these transport preparation options:
  • Disconnect the rear caliper from its mount, remove it from the rotor then hang it by a bungi cord from a pillion grab handle.
  • Find the source of the leak then put a rag around it so it doesn't leak more.
  • Transport the bike to the shop by helicopter or furniture dolly.
  • Solicit volunteers to move the bike coffin-carry style.

Rats, helicopter is down for maintenance and the furniture dolly is across the border looking into a sex change operation.  Likely volunteers are still suffering post-eclipse hangovers.  I guess I'll clean off the disc rotor, get it to the shop, and check fluid levels for rear brake and final drive, and observe if further leaking occurs.

  • Cali. Coast 93441
  • '94 K75

Offline wally.fisher

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Re: Leak:Final Drive seal or Brake Piston?
« Reply #6 on: August 27, 2017, 04:20:41 PM »
No worries on suspecting the dog, the bike has been parked in a closed garage. 

All parts of the shock are dry and no signs of leaking around the final drive mounting bolt.  Are there other visual indicators of a blown shock?

Rats, helicopter is down for maintenance and the furniture dolly is across the border looking into a sex change operation.  Likely volunteers are still suffering post-eclipse hangovers.  I guess I'll clean off the disc rotor, get it to the shop, and check fluid levels for rear brake and final drive, and observe if further leaking occurs.
Is it not coming from the rubber boot between swing arm and rear drive . Indicates a damaged seal on the rear drive or the gearbox output shaft seal.

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Offline Scott_

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Re: Leak:Final Drive seal or Brake Piston?
« Reply #7 on: August 27, 2017, 05:15:22 PM »
won't have that on a monolever K75, and it would be too far down to the the upper flex boot at the transmission end.
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Offline Laitch

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Re: Leak:Final Drive seal or Brake Piston?
« Reply #8 on: August 27, 2017, 05:18:00 PM »
Is it not coming from the rubber boot between swing arm and rear drive
The photo with the boot is j o's K1100 probably.

Farmrjohn's bike might turn out to be one of those relics that weep only during momentous occasions and create pilgrimages. His shop might become a shrine!
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline wally.fisher

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Re: Leak:Final Drive seal or Brake Piston?
« Reply #9 on: August 27, 2017, 05:20:27 PM »
won't have that on a monolever K75, and it would be too far down to the the upper flex boot at the transmission end.
Yes youre right, now why did i assume this to be a paralever. Apologies.

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