Master cylinder problem??

[Tackettr]

After several days of 20-30 degree weather, I went out to fire up one of my dueces. After warm up I was going to move it and the brake pedal went to the floor. Tried to pump it back up to pressure but never would. I looked at every wheel and all were dry, however fluid was coming out of the vent valve (Axle vent) on top of MC. I figured it was bad and pulled it to get it repaired. After I had it out, I did a quick bench test and it seems fine now and pressures up. Could the cold weather created some type of air void or is there a real problem that needs fixed?

Also, I hope its cheaper to take it to a local truck brake place and get rebuilt as oppose to paying $125 plus shipping for a new one?

 

[TommyG45]

125 sounds steep, for some reason 85 bucks from clark when I got a new one, about 6 months ago..... I am getting old and my memory could be slipping, like my clutch

 

[cbvet]

Years ago we would rebuild master cylinders just like wheel cylinders. Not difficult.
I would guess parts would be available, or generic.
If I can get my hands on a loose one, I'll try to rebuild it.

Eric
CBVET

 

[poppop]

They are easy to rebuild yourself. Get a cylinder hone from the auto parts store and polish the bore. If it polishes out smooth and shiny install new cups and you are good to go. The last two I did would not clean up so I got a new one off e-bay for $55.00 and a second good take-off at the Ga Rally for $15.00.

 

[bottleworks]

$125 is way too much. OD Iron sells New stock M/C's for $81. And new stock rebuild kits for $25...

Are you sure the master cylinder is your problem? Not an Air-Pak Issue?

 

[Tackettr]

Just did a quick search on the web at a couple places, both had them at $125, I thought that was pretty steep.

I'm not sure what my problem is. I was sure it was the MC, but now that I have it off, I'm stumped. No significant loss of fluid after I pumped them like crazy to mark a tire when I initially thought it was a wheel cylinder. It now seems to be holding pressure fine on the bench. The only leaking fluid and not much, was out the top vent which is an axle vent I installed. I'm thinking if it was airpack or wheel cylinder there would be significant loss (1/2 or more) as much as I pumped the brakes.

I think I will reinstall the MC and bleed the system and see what happens.

 

[Warthog]

Hey Tackettr.

Sounds like it may be your airpack. I have made a pressure bleeder that makes bleeding the system just a few minute job.

I will get it to you or M1075. I will making an emergency trip to Lake Charles, LA tomorrow. I can leave the bleeder at the office or get it to you in the middle of the week.

Anyone needing something delivered between OKC and Lake Charles in the next two days?

Warthog

 

[gimpyrobb]

If you want to rebuild your airpack, there is re-build kits in the classifieds cheap.