air compressor

[heavyhaulerss]

i just had my truck compressor replaced with a rebuit one. the one on truck was original & after 12 years i thought it must be wore out, due to recently taking quite a while to build up air. i was told to replace. new one is on & it takes longer to build than the old wore out one?? checked all lines . e.t.c. no leaks. the old one was leaking or passing oil i was told. drained air tanks. got no oil at all out there. replaced air dryer filter. it had oil in it. any reason why the new compressor takes so long too build air? i remember a couple years ago when you could watch the air gauge needles move in tandem quickly to 120 lbs. 2-3 min tops. now 8-min to get to 120 lbs .. any suggestions?

[9200IH]

Was your old air compressor a 750cfm and they replaced it with a 550cfm? A 550 is about $150.00 cheaper than a 750 and it would pump up slower.

[heavyhaulerss]

i would assume it's the same. i took all the nubers off old one & truckpro ran the nunbers & gave me a rebuilt one. he never mentioned anything about cfm's. my mechanic didnt say anything about it being anything less than original eqiup replacement. one thing i have noticed though. is a couple times the air would go from a creeping crawl barely moving 7 then would rise real quick from 100 to 120 in a 8-10 sec. i just got truck out of shop this afternoon. have not really took out on road yet. looking at my receipt it says tf 550 i would think yeah it is the same. as he cross referenced the numbers

[roadranger]

If your air pressure comes up fast enough to meet the DOT spec and you have no oil in your wet tank I wouldn't mess with it. The air dryer is supposed to have some oil in it - it has two medias in the element, an air drying media and an oil removing media. Water and oil should both blow out the bottom when the compressor kicks off. No oil coming out may mean that the compressor isn't getting proper lubrication :shock: .

[SilverWulf]

Depending on the age of the truck, you may have buildup in the line from the compressor to the tank or in the tank itself. I've run into this a couple of times. Where the line enters the tank, pull the hose loose and take the fittings off the tank. See if the hole is clear and check the one way valve to make sure it isn't getting buildup which would restrict the airflow. Check the hose for free flow while you are at it.

Dan

[heavyhaulerss]

thanks for the tips. i did take lose the fitting at the back of both 1 & #2 tanks. nothing but clean air came out. i'm talking about the air tanks. i was thinking there may be some sort of restiction in a line somewhere. what kinda surprized me was the air would stay at 90 lbs for about 2 min straight & not move at all. then all of a sudden it would shoot to 100-110 in a couple seconds. idling 8 'gs. going out tomorow. i'll get straightened out & post results as soon as i can. thanks once again.

[heavyhaulerss]

after replacing my regulator that regulates the cut out press. & fixed 2 leaks, my compressor is now doing it's job.