Author Topic: Rear master cylinder question  (Read 137 times)

0 Members and 1 Guest are viewing this topic.

Offline crag antler

  • Mini Bike
  • **
  • Posts: 184
  • AREA: Southeast Area
  • COG#: 8277
  • Membership Level: Active
Rear master cylinder question
« on: November 09, 2019, 07:58:38 pm »
So I've rebuilt the rear caliper. While bleeding the old fluid out, I noticed that I was not getting much movement at the pedal.
My thought is that I may have an issue with the master cylinder.
So do I pull the cylinder apart and check the piston or just order the piston assembly from Partzilla for $38?
Murphs has the front rebuild kit but not the rear.
Looks like the last bit to fix before I can get back on the road.  :motonoises: :motonoises:
Doug aka crag antler
00 Kawasaki Concours 60,000+ miles. Bafflectomy,Bar risers, Murphs kneesavers, blockoff plates, allen head screw set,headlight upgrade. LED headlight, driving lights, free power mod, JC Whitney trunk, Go Pro mount,’06 header w/Jet-Hot ceramic coating, over flow tubes, 2 minute mod, carb spa and Performance Exhaust Sprocket by SISF

Offline crag antler

  • Mini Bike
  • **
  • Posts: 184
  • AREA: Southeast Area
  • COG#: 8277
  • Membership Level: Active
Re: Rear master cylinder question
« Reply #1 on: November 10, 2019, 03:49:59 pm »
I was checking the piston action this morning and got a big slug of old brake fluid out. Now the activation of it is operating properly. :beerchug: :)
Doug aka crag antler
00 Kawasaki Concours 60,000+ miles. Bafflectomy,Bar risers, Murphs kneesavers, blockoff plates, allen head screw set,headlight upgrade. LED headlight, driving lights, free power mod, JC Whitney trunk, Go Pro mount,’06 header w/Jet-Hot ceramic coating, over flow tubes, 2 minute mod, carb spa and Performance Exhaust Sprocket by SISF

Online connie_rider

  • "OtP" {retired/assistant} Slave Labor
  • I Need a Life
  • ******
  • Posts: 9904
  • Help us make "OtP" possible! "AGAIN"
  • AREA: South Central Area
  • COG#: 4154
  • Membership Level: Asst. Area Director
Re: Rear master cylinder question
« Reply #2 on: November 10, 2019, 04:10:30 pm »
 :sign0098: :sign0098:

Ride safe, Ted
14 Connie (Traveler II) / 03 Connie (Buddy)
Gone but not forgotten; 87 and 00 Connies..

If your not already a COGger, "consider becoming one".
Help us make "OtP" possible again!!

Offline crag antler

  • Mini Bike
  • **
  • Posts: 184
  • AREA: Southeast Area
  • COG#: 8277
  • Membership Level: Active
Re: Rear master cylinder question
« Reply #3 on: November 10, 2019, 06:13:04 pm »
Well, I thought I had it. Put it all back together and pushed the pedal but soft as can be.
Pulled the line @ the cylinder and had flow.
Pulled the line @ the caliper and no flow.
Blew the line with brake fluid, stainless steel wire and even compressed air.
After all that, minimal flow with bits coming out. Not enough pressure coming out.
Guessing most of this is my fault for not maintaining the brake system. Brake fluid looked like tea. >:( :'(
Gives me the opportunity to go to Murphs and get the braided lines.
Going to order the piston assembly for the cylinder and rebuild the master.
Lines come in, replace all brakes and clutch lines and flush.

Moving forward, I’ll be putting a reminder on my calendar for the flushes.
Glad to do this @ home as opposed to losing the brakes on the twisty NC roads. :great:
Doug aka crag antler
00 Kawasaki Concours 60,000+ miles. Bafflectomy,Bar risers, Murphs kneesavers, blockoff plates, allen head screw set,headlight upgrade. LED headlight, driving lights, free power mod, JC Whitney trunk, Go Pro mount,’06 header w/Jet-Hot ceramic coating, over flow tubes, 2 minute mod, carb spa and Performance Exhaust Sprocket by SISF

Online connie_rider

  • "OtP" {retired/assistant} Slave Labor
  • I Need a Life
  • ******
  • Posts: 9904
  • Help us make "OtP" possible! "AGAIN"
  • AREA: South Central Area
  • COG#: 4154
  • Membership Level: Asst. Area Director
Re: Rear master cylinder question
« Reply #4 on: November 10, 2019, 07:56:08 pm »
Master cylinders don't fail very often.
I suspect you just have a lot of air in the system.'
Have you tried a vacuum brake bleeder?
{available at Harbor freight}

Ride safe, Ted
14 Connie (Traveler II) / 03 Connie (Buddy)
Gone but not forgotten; 87 and 00 Connies..

If your not already a COGger, "consider becoming one".
Help us make "OtP" possible again!!

Offline crag antler

  • Mini Bike
  • **
  • Posts: 184
  • AREA: Southeast Area
  • COG#: 8277
  • Membership Level: Active
Re: Rear master cylinder question
« Reply #5 on: November 10, 2019, 09:26:59 pm »
For the moment, I'm waiting until the next paycheck. I put in almost 20 hours OT and was told Friday that there will be as much as I want in the future.  :great:
In fact, I'm about to go in tonight for an emergency steam shutdown. Normally M-F. ;)
When I order the braided lines, it looks like I'll go with the 2 line system for the front brakes.
Any thoughts or ideas would be awesome  :beerchug:
Doug aka crag antler
00 Kawasaki Concours 60,000+ miles. Bafflectomy,Bar risers, Murphs kneesavers, blockoff plates, allen head screw set,headlight upgrade. LED headlight, driving lights, free power mod, JC Whitney trunk, Go Pro mount,’06 header w/Jet-Hot ceramic coating, over flow tubes, 2 minute mod, carb spa and Performance Exhaust Sprocket by SISF

Online connie_rider

  • "OtP" {retired/assistant} Slave Labor
  • I Need a Life
  • ******
  • Posts: 9904
  • Help us make "OtP" possible! "AGAIN"
  • AREA: South Central Area
  • COG#: 4154
  • Membership Level: Asst. Area Director
Re: Rear master cylinder question
« Reply #6 on: Yesterday at 01:43:12 am »
I think most go with the 2 line setup.
That is what I have on mine.

Ride safe, Ted
14 Connie (Traveler II) / 03 Connie (Buddy)
Gone but not forgotten; 87 and 00 Connies..

If your not already a COGger, "consider becoming one".
Help us make "OtP" possible again!!

Offline konehead

  • Road Bike
  • ***
  • Posts: 340
  • AREA: Southeast Area
  • COG#: 9065
  • Membership Level: Active
Re: Rear master cylinder question
« Reply #7 on: Yesterday at 03:04:47 am »
2 line system is better.  It should come with the long banjo bolt to connect both lines to the master. Then route them down to the calipers bypassing the spliter...  take it off u wont need it...

Offline Boomer

  • Crotch Rocket
  • ****
  • Posts: 1164
  • Wickford, UK
    • Boomers GTR Site
  • AREA: Northeast Area
  • COG#: Forum
  • Membership Level: Forum Subscriber
Re: Rear master cylinder question
« Reply #8 on: Yesterday at 09:32:00 am »
The only issue with braided hose on the rear brake is that it will make the brake even more on/off than normal.
Mine got so bad on my old '86 that I had to introduce a small air bubble deliberately to prevent rear wheel locking.
The 89 still has the OEM rubber hose that has some give in it so no need.  :great:

I bleed through both brakes and the clutch once per year on both bikes.
It takes a few minutes with a compressor vacuum bleeder and costs a couple of pints of DOT4 so worth it for peace of mind.
George "Boomer" Garratt
Wickford, UK
CDA-007