Compressor problem viair 380c

I just bought this truck and the guy said the compressor was out,I can fill the bags with home compressor and it will stay aired up for a few hours.The compressor turns on but is putting out very little air Do i need to rebuild it or is it a check valve issue i have no leaks anywhere else.

they have new seals for the head 380c might be time to take it apart and rebuild it. my old 380 i took it all apart cleaned up everything and works great cleaned the brushes on the motor too. easy to take apart.
here's a link to a rebuild
http://www.s10forum.com/forum/f125/viair-380c-slowing-down-433894/

agree with home dude. my 450s did the same thing time to call viair