Trouble Shooting Brakes

[harleyrkc]

I have a truck with absolutely no resistance in the brake pedal. I've bled the brake system and still have no resistance, and I've read through the brake section in the TM's. Basically the TM's state change the MC or change the Airpack. Does anyone have any insite on actually troubleshooting the MC or Airpack? I think the seal is shot on the piston in the MC but I'd like to attempt verification before pulling the MC to rebuild it. Also I've read about using air tool oil to lube the airpack but there's no info on exactly where to put the oil in the Airpack.

 

[bones1]

Sounds like your master is bypassing. Did you check the lines under the truck?.

 

[WillWagner]

The air pac will usually just make the brakes feel like they aren't "power" assisted or puke BF out the road draft tube, not make the pedal mushy. You have a failed M/C. If you rebuild it get good Wagner parts, not the Chinese made New Star stuff.

 

[dozer1]

Ya. you can't go wrong with a MC replacement. You may have great luck by honing and kitting your old one, but they are not too expensive to replace and worth every penny. Once done, pressure bleed and bask in your solid brake peddle. . lol 99% sure

 

[bones1]

Have you had trouble with New Star parts?.

 

[WillWagner]

Not me personally, but others I know. The cups turn inside out and break into pieces parts.

 

[bones1]

Boy, that's not very good. I got new wheel cylinders today from Napa and you guessed it.....made in China. They look decent though.

 

[harleyrkc]

Ill take this as confirmation I need to rebuild. Now how do I put the airtool oil in the airpark?

 

[scoutmanadam]

just disconnect the airlines to it and add just a few drops and hook everything back up, of coarse, drain all the air out of the system first