a/c compressor on - doesn't cycle off

howdy - 1998 international 9400 - replaced a/c compressor and clutch - 1st few hours - no cycle -but truck fan cycling every minute or two {high pressure ? } now it's all off and no Freon - I've been told maybe the expansion valve at fault for no cycle ? - also maybe a hi-pressure purge responsible for no Freon - does hold -30lbs for 10 minutes then loses vacuum - I don't yet see a visible leak spot - any ideas, before I start ripping stuff out -- thanks, tom

 

thanks, folks - I will check valves - and yes - vacuum loss is what it is - dye is coming - and i'll take any and all more hints - I'm flying blind here thanks

 

Hello - flying blind - simply not familiar - changed a few compressors and clutchs - easy bolt stuff together work - yes sir, recently got manifold set -
did run 30 lbs vacuum for about 5-10 minutes - then down and down - back to 0 - exactly what would " pressure loss " mean - mechanically, I mean -
as I haven't yet seen an oily mess anywhere on the system - I got some dye - tomorrow I figure on charging it up again to see what pops up =also picked up a new expansion valve - hope maybe that might have something to do with the original problem when I put on the new compressor and clutch Tuesday - the hi pressures and no clutch cycling - yeah just guessing here - also thought to remove the condenser - clean and flush - after 5 or 6 compressors in the last 15 years - it must have a load of oil and crap in it -- reckon it can't hurt -- more info please -- thanks, Tom

 

yep, i'll be climbing over it all - I know, ya'll thinking better me than you - at least winter ain' too far off -- thanks, tom
this morning I added dye and a couple of cans - used hot water trick - put can in pot of hot water - it all went in -BUT - compressor never went on
low side was 70 lbs -- hi side was only 50 lbs - [ well, no compressor activity ] -- emptied system - hooked up vacuum - pulled -30lbs for 45 minutes - turned vacuum off - held -30lbs over 2 hours - I don't know! - now i'll replace expansion valve and clean out condenser - any theories out there? thanks, tom