rear brakes went soft

[garyS-NJ]

I delinked my brakes last year and things have been well but since de-linking, my rear had a very wooden feel (pedal hard feel with little travel from off to tire skidding). In my delink, I plugged the port for the front brake line and ditched the proportioning valve to put the rear brake line on that port. Last week I did some front end work and on my test ride found the rear brakes dragging. turns out the piston in the rear brake master was stuck (first it was dragging and then at some point, I couldn't get pressure to the caliper!). So I unstuck the brake master piston and cleaned it out and reassembly and bleed and I had brakes for a very short ride. then the pedal went down and no brakes. So I bled again and got air out again for a firm pedal feel but again it went soft, no back brake. At this point I'd be sure to have a brake fluid leak but I washed it after each bleed and the brake pushrod is dry.. I'm having a hard time believing that the brake fluid is squishing past the piston and not leaking out and also hard to understand how I get air in there without any fluid out.. I found rebuild kits on ebay for $70 but I was wondering if a later brake cylinder could be installed for better performance and cheaper rebuilds. And I guess air could be leaking into my Teflon taped bolt plug but I would think that I would more likely see fluid leaking out there..

[kevin-vic-b.c.]

Only three things I can think of to create soft pedal are, air, leak, over heating.

Maybe #4 would be old fluid.

with the system delinked I think that leaves the rear system with a very small amount of fluid in total so it would take such a small amount of leakage to cause an issue I think.

Just my thoughts

[Marcarl]

Brake fluid could be built up under the dust seal at the caliper.

[Condor]

Just a thought. Get rid on the Teflon tape on the banjo and use a new crush washer......

[camos]

Just a thought. Get rid on the Teflon tape on the banjo and use a new crush washer......

Good idea. The use of Teflon tape in hydraulic systems can be problematic. When applying to a bolt or adapter the first thread or two should be left bare and the tape must be wrapped in the correct direction or there is a risk of a small piece of tape getting into the system and causing a blockage. The threads of fittings used in hydraulic systems are normally tapered pipe threads or if straight cut they would normally use an o-ring which would be quite different from a bolt with an o-ring.

[garyS-NJ]

I'm such s dope.. I got a good look during the day with my glasses and saw with pedal pressure, it was leaking at the rear line connection (where the proortioning valve used to be). So I left my goofy Teflon taped bolt alone.

 

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[mmaleney]

Glad you found the cause.

 

Did I read somewhere that you had to put in a new starter clutch in you're bike and you used one sold on ebay? how is that part working out for you? Mine is getting to that stage.

 

Thanks.

[Air Ready Auto]

Glad you found the cause.

 

Did I read somewhere that you had to put in a new starter clutch in you're bike and you used one sold on ebay? how is that part working out for you? Mine is getting to that stage.

 

Thanks.

 

 

Not intending to hijack the thread but I installed a "heavy duty" (6 rollers instead of 3) starter clutch in mine purchased from ebay. From everything I've read, the longevity of the heavy duty ones is slightly longer than the stock ones. If you intend to keep your bike for life than you should really contact Dano on the sight. He makes a starter clutch mod that will outlast the engine.

[mmaleney]

Yes I know about Dano, thing is I have 4 ventures sad to say not all can be keepers.

[Air Ready Auto]

Yes I know about Dano, thing is I have 4 ventures sad to say not all can be keepers.

 

 

Well that's just silly. Every venture is a keeper.

[bongobobny]

Yeah!! just ask Yammer, or Condor, or...

[garyS-NJ]

I put one of those heavy starter clutches in a bike but haven't got it running yet. But it cranks .

 

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