juston.ledbetter

wow great post thanks freight train. I has 2 tanks

thanks for the support guys

HeavyGunner, could you elaborate on the what, when, and where. of a bad diaphragm in a can. thank you

thanks for the quick response. checked for leaks this morning. found one small one, but I don't think it is severe enough to cause such a drop in pressure. purged the tanks did find condensation with a little oil. but still doing the same thing. the air does not continue to drop while you are pressing the pedal. it drops as air moves from the tanks to the chambers. then holds steady. I did have someone work the pedal while I listened for air leaks. no chambers are leaking or valves that I can hear.

my name is juston ledbetter. I am a mechanic for a trash company. I work on primarily late model macks. I am the only mechanic for this small company, and I have inherited a fleet of run down pos's. I only have about 2 years of mechanic experience, and yes I am in over my head.

sorry if this is in the wrong area. my problem is when I press the pedal the air drops from 120 to 90 with only one pedal push. then from 90 to 60 so on so forth. 1998 mack front end trash truck