M1081 air leak problem

[Rene M]

When i hold the foot brake down i get two air leaks. One in a valve that vents on the rear right side and the other vents out of the front blue glad hand. the blue glad hand has a vent on it and dumps the air tanks fast. the front blue glad hand has a vent on it which seems strange to me.

 

[NDT]

The vent on the front blue service glad hand cover is correct for the FMTV. Remove it and apply the brakes a few times and see if that corrects the fast leak. There are several threads here with brake troubleshooting guides along with trade part numbers for the rebuild kits for the various valves.

 

[Rene M]

Im hunting " as we speak" a air diagram to figure out how the parking brakes work as it does not have spring chambers. i think a chamber may be bypassing.

 

[Suprman]

The rears have springs. They park the truck. The fronts are service only. There are 3 check valves behind the drivers for step they crack inside and you will get a service air leak when applying the brakes.