looking for some help, I got a 1998 f/l with air brakes, air psi build up is very slow from 0 to 60 then builds up fine, I checked the steel braided line from comp to dryer and is not plugged, changed governor, kinda stuck any thoughts?
Bendix? Have you plumbed a manual gauge into tank(s) and verified your dash gauge is reading correctly
May be the unloader valves in your compressor are leaking til compressor builds some heat and seals up when pressure gets to 60 psi...? seems like it was $20 or less for a Bendix unloader kit... last time I got one...
Have you tried plumbing shop air into system and watching gauge operation? also if a valve is leaking at low pressure you might be able to hear it without engine running... I have seen/replaced threadle valves that leaked on class 8 trucks at low or no pressure.. then after air started building leak went away and worked fine when driving...just built air slow at first start up and couldn't hear leak with engine running...