We have a M105X and the A/C is blowing warm air. Pulled a vacuum and tried charging the system. The compressor clutch is engaging. Could the receiver/dryer be clogged?
A/C won't take a charge
- Thread starter M105X
- Start date
I'm not sure I agree with that. Not that I've tried it, but I believe you can charge a system without pulling a vacuum. Not saying it will work properly, or last very long, but I think it's possible.
The claim here is that it won't take a charge. That doesn't sound like a vacuum related issue to me. I'm still waiting to hear what his pressures were. I'm wondering if he even had gauges installed or maybe was just using recharge kits with a generic low/medium/hi pressure gauge attached.
You ARE attempting to charge it using the LOW side… Correct..?
You HAVE by-passed the “low pressure” switch…?? (The compressor DOES INDEED actually “run”..??)
It reads as-if you are using a can of refrigerant and simple hose w/valve…. and not a dedicated gauges set-up…? If so, are you familiar with the valve on the hose..? (puncture can, back-off / open valve)..?
You HAVE by-passed the “low pressure” switch…?? (The compressor DOES INDEED actually “run”..??)
It reads as-if you are using a can of refrigerant and simple hose w/valve…. and not a dedicated gauges set-up…? If so, are you familiar with the valve on the hose..? (puncture can, back-off / open valve)..?
I have not bypassed the low pressure switch. The compressor does run
Apologies for seemingly asking simple-minded questions…but you did not answer question #2 …so I lept to that level….
I’ve never experienced a dryer clog….but I have witnessed expansion-valve stuck closed.… tho’ not sure if Kubota used that vs expansion Tube…
that should be good if it maintains it. are you using a kit from say autozone or a hardware store that has a little dial window on a can or a proper set of gauges for the ac system your charging?? because if your using one of those cheap diy in a can things your probably going to cause a LOT of damage to your compressor as they have sealant in them which will definately make things stop working right
i used to maintain my own ac systems back in the 90s but todays world ac has advanced so much and its gotten more complicated the correct tooling and knowledge is very expensive. i dont do my own now on modern ac its just cheaper to hire the guy to do it since they do it all the time and have invested in it. but i do know for sure those diy cans are a guaranteed way to paying for a complete new system....
just my thoughts do as you will
Last edited:
You stated you do have gauges on both sides. The compressor does run. No need to bypass the pressure switch then. Once you introduce freon into the system the pressure switch will close and allow the clutch to engage. Rarely would a switch bypass be necessary.
I'm still curious as to what the pressures read while the charging attempt is being made? When a system won't take a charge it's often an expansion valve problem. If so, the high pressure will rarely get above 100 PSI while the low side will drop into a vacuum no matter how much refrigerant you add. Does that sound familiar?
I'm still curious as to what the pressures read while the charging attempt is being made? When a system won't take a charge it's often an expansion valve problem. If so, the high pressure will rarely get above 100 PSI while the low side will drop into a vacuum no matter how much refrigerant you add. Does that sound familiar?
It sounds like you have a gauge or can tap issue. Are you screwing in the top of the connector after plugging it on the fitting to open the shrader?
IF it's still "in the red" as in showing a vacuum the only way the compressor clutch is engaging is if the low pressure switch is stuck closed.
IF it's still on a vacuum try opening both high and low side valves with the engine not running and see if it will pull a can of refrigerant in. It should pull almost a full can in from a vacuum without it running. Of course you should never open the high side valve with it running.
In my 50+ years experience I have never seen a clogged drier. I have seen them come apart and clog the expansion valve screen or orifice tube.
Another possible dumb question. Do your gauges have the connectors that snap on and open the schrader valve for you, or do you have the type of connectors that require you to screw the valve open?
After pulling a vacuum and introducing freon into the low side, you should see the high side gauge start moving, even without the compressor running.
I will say that I have seen broken compressor shafts. The clutch engages, but it doesn't turn the internals.
After pulling a vacuum and introducing freon into the low side, you should see the high side gauge start moving, even without the compressor running.
I will say that I have seen broken compressor shafts. The clutch engages, but it doesn't turn the internals.
YES! I’ve seen a couple of broken compressor crankshafts. (one of them on a brand new compressor. This was back in the early ‘70’s when I was installing under-dash new units for dealers in ‘71 Toyotas which did not come from Japan with AC.)
(a poor-man’s way to create a low-grade vacuum on an empty system is to open the high side and let the compressor blow it out.,.. which is one way to confirm the compressor actually works, although no professional would likely approve that method.)
Last edited:
Coming from left field . . . I noticed recently while setting up a mini-split that the hose, maybe all 3, only had the doodad that pushes the schraeder valve on one end. If I had reversed the hose, it wouldn't have let refrigerant in.