I have a 1988 4964F that was originally an over the road truck with sleeper now its a dump truck the trucks A/C was working great until about 3 days ago it wasn't cooling the cab very well. So I added some freon and it started working great then I found the leak fixed the leak and now it keeps freezing up and its making some vibration noise around the expansion valve. after looking at my gauge connectors found some junk that looks like its coming from the high side of the system like I have a ac line or a drier that's coming apart internally. So I guess now it the time to take it all apart and replace everything to avoid more problems in the future. My main question is am I going in the correct direction and what is the part numbers for the switch and drier. PS my dealer isn't worth calling they never call back and say my truck is too old and to call someone else. attached is all the pictures
Compressor looks to be Compressor - Sanden 4646 Expansion Valve looks to be Expansion Valve - Universal ABP N83 308011, Truck Air 12-2012G, MEI 1607 Dryer looks to be Receiver Drier - Western Star 088586-00 But I can't guarantee any of that. You need to flush the whole system out really good also.
If you had the proper charge, expansion valves probably sticking. I wonder where the crud came from? Usually from a failed or failing compressor. Once it gets in the condenser it’s best to replace, since open fin/ header design can’t be cleaned, since it’s not one closed loop.Or so they claim. Hoses need to be flushed, at least. I took my bunk apart, flushed evaporator with cleaner and compressed air. Of course replacing everything is ideal. I’d just try my best to flush what I could. Blow out with air. Yeah nitrogen is ideal , I’ve never used it. Change expansion valve, dryer, pull a vacuum. Fill er up. Contrary to popular belief, vacuum doesn’t pull air, or debris from system. Instead by creating a vacuum on the system, it causes heat, and boils water out. Worst case scenario is you have a trash filled condenser from a compressor that’s failing. You’ll know soon enough. May or may not plug new expansion valve, or air dryer again, if it fails right away. Just have to flush the hose again. Might get lucky and any minor trash with get picked up by new dryer. On the other hand, if that doesn’t work. You may end up needing a compressor. If that’s the case, replace condenser, flush lines again. May end up having to buy another expansion valve and dryer. Probably not, that’s been my experience anyway. For now, hardest part is getting the lines off expansion valve, without destroying them.
Dryer should be oem#s, ABON83-319314. Or 61506-3402, Or RD5-7568-0, Or RD5-7517-0. Any of those will work. Truck Air Brand (Available at Truck Pro) or MEI part # 07-1605A replaces all the OEM #s Dryer should have an o ring type switch port. Pretty sure that switch is a trinary switch.
They can be upgraded easily. Good catch, I missed that. My guess is it’s been upgrade with a conversion fittings kit years ago. Problem now will be finding another. Next to impossible, or very expensive at best.New style compressor is probably in order, along with 2 new lines, with 134A ports.
