The GMC CCKW

Hi

When I take my CCKW with Banjo axles out for a 100 mile or more spin around the block, my rear axles build up air pressure. Yes, I have changed the air breather cap assembly twice with 2 different caps, but I still have the air pressure (seems about 5/10 psi). Is this the normal pressure before the check valve releases itself? What I am trying to avoid is grease/oil coming out into the brake shoe area.

Thanks for your thoughts.

Concerned about air pressure build up in tandem rear axles and the possibility of discharging oil/grease unto the brake shoes because of this air pressure, I solved my own problem by installing two remote air breather vent caps high above the frame rails. I used a Ford Part #F67Z-7034-A Vent Cap Breather (cost about $15.00 and bought thru NAPA). This Ford part is really great as it is made of super fine mesh and a strong metal cover. I connected the breather to the axle using 20" of vacuum hose.

That sounds like a good tip and would be very useful if you were to do any wading.