Master cylinder question

[pa.rich]

I have a five ton. It had brakes when I first drove it. Then I lost any pedal . It was parked for a year. I never checked the fluid. Now I want to use it . I checked the fluid and it was bone dry. I refilled it. No pedal at all ,not even resistance on the pedal. Should I replace the master cylinder? I realize it will have to be bled but how can I bleed it if there is no pedal pressure? What should I do?

 

[cbvet]

I've found that even though it may not feel like there is any pedal resistance, there is usually enough pressure to bleed the brakes.
Fill it, pump the pedal, look for leaks.
If no leaks are found, start bleeding. Pedal should start coming up.
Eric
CBVET

 

[gimpyrobb]

Rich, if the master was empty, you will have to atleast bleed the master. If you get under the truck, you will see a bleed port on the end of the master itself. Once the fluid level gets so low, air gets into the master cylinder's-cylinder. When I rebuilt mine and re-installed it yesterday, I had about 4-5 pumps to get the air out of the master itself. Give that a try and let us know. And yes, a 1 foot piece of tube will allow you to squirt the BFS back into the master's reserve chamber so you don't waste much fluid.

 

[pa.rich]

Wooo Hoooo!! Drove her out of the garage with good brakes! Thanks for the quick replies Gimmpy and Cbvet.And my wife ran the reply out to the garage for me and Watched me drive around the property . Both of us overjoyed to see the beast out and running around. Btw, that fluid will need to be purged out. It was dirty and nasty. I will sernd pics later today.

 

[gimpyrobb]

Glad to hear it.

 

[bottleworks]

Did you find your leak? There is a leak somewhere. Brake fluid doesn't just disappear.

 

[roger-wilco-66]

If the fluid dissapears without a noticeable outside tell-tale sign it could have leaked into the pressure chamber of the airpack. Not good, and will generate another massive problem sooner or later.
Also if I had a dry mbc over a longer time I'd surely open it to have a look inside and inspect the cylinder walls for corrosion. When it is only slight one can sand it with fine grit sandpaper and / or hone it to get it smooth again so the seals of the piston don't get damaged by the ragged surface (sorry my bad technical english).
From my own experience, I could send some pictures of what that scenario can look like... and you surely know there is no fallback in the deuces brakesystem when something in that area critically fails.

 

[BEASTMASTER]

don't forget about the bleeders on the air pack.

 

[pa.rich]

Thanks guys, Yes the rite rear brake cylinder has a slight leak. I intend to get to that later. But for now I just want to move it under the dump body, and everything is on a side mountain so I wanted brakes for today. Thanks