When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Just vacuumed and refilled my ac system. My AC Compressor comes on just fine, but doesn’t shut off. Air is cold, has plenty of refrigerant, but runs constantly. I leak tested with vac pump and didn’t leak at all. System won’t take anymore refrigerant. Thoughts?
Do you have gauge set or at least low side gauge? If a/c is slightly over charged pressure could stay high enough not to cycle while parked. You need to see how far the low side falls @ 2k rpm. Reading should fall below 28 psi and compressor disengage.
Do you have gauge set or at least low side gauge? If a/c is slightly over charged pressure could stay high enough not to cycle while parked. You need to see how far the low side falls @ 2k rpm. Reading should fall below 28 psi and compressor disengage.
hmmm...interesting. It cycled a bit while I was charging it (so it obviously CAN engage/disengage) but when I got it to 'full' pressure it stopped cycling. I only tested it while parked and idling. I have a gauge on the low side, it was just slightly above 30 psi, which is what I was told to have in it while charging.
I will test while revving the engine (I assume having an assistant press the gas while parked and in neutral will be enough to see if it's working?). Should I let some pressure OUT and see if that helps?
I didn't realize that OVER charging would cause this, I thought the compressor continually spinning meant that it needed more.
I would happily hook up a gauge to the high side but I don't know what kind of adapter I'd need to accomplish that.
Thank you so much for the help! That sounds very feasible for this situation.
More info: I saw the compressor clutch seemingly slip. The clutch stuttered a bit and then would re engage. I wonder if it’s slipping and not building pressure.
You will need high side adapter. Only connector disconnect high side when a/c has been off for about 5 minutes. High side in simple terms 100 + the outside temp. So high should be about 170 when it's 70 degrees. Humidity can be a factor depending on readings. Post high and low side pressures when possible. Tomorrow if you leave gauge attacted the pressure should equal outside temp within a few degrees if system if full. Higher if over lower if low.. What was done the a/c was recharged?
You will need high side adapter. Only connector disconnect high side when a/c has been off for about 5 minutes. High side in simple terms 100 + the outside temp. So high should be about 170 when it's 70 degrees. Humidity can be a factor depending on readings. Post high and low side pressures when possible. Tomorrow if you leave gauge attacted the pressure should equal outside temp within a few degrees if system if full. Higher if over lower if low.. What was done the a/c was recharged?
i swapped out the high pressure valve and the hose it’s on with a known good one. Vacuumed the system, held 28 in hg for 30 minutes. Still had vacuum 24 hours later when I reconnected the adapter. Put about 48 oz of Freon in and 6 oz of oil. I got it to about 30 psi. It started off without the compressor engaging, and then it engaged intermittently, then didn’t shut off at all.
So you got R12? 48oz or 3 lbs is a little too much I believe although I don't know what year or how much you were supposed to install. There is a correlation the R12 in the system in at rest for atleast 8 hrs the pressure is approximately the outside temp. Accumulator should catch excess oil.
So you got R12? 48oz or 3 lbs is a little too much I believe although I don't know what year or how much you were supposed to install. There is a correlation the R12 in the system in at rest for atleast 8 hrs the pressure is approximately the outside temp. Accumulator should catch excess oil.
It is r12 REPLACEMENT called Redtek. I’ve used it before and it works great. 44oz is what it’s supposed to be. I’m sure I got a little bit of air in and Some of the Freon probably leaked. Regardless I think it’s pretty close to what it should be.
If the clutch was slipping, it wouldn’t build enough pressure and the low side pressure would stay higher right? I wish I had access to the pressure for the high side...I’ll see if I can find an adapter.
It should eventually equalize completely right? Then I can check from low side port?
I'm not familiar with Red tek 12a I befiefly read a little about it. Conversion Chart shows 1 lb of Redtek equals 3 lbs of R12. So if you put 48 oz of Redtek in it seems system is way over charged. When i googled Redtek it did bring up a video, although i didn't watch it maybe tomorrow, I think you should review video.
I'm not familiar with Red tek 12a I befiefly read a little about it. Conversion Chart shows 1 lb of Redtek equals 3 lbs of R12. So if you put 48 oz of Redtek in it seems system is way over charged. When i googled Redtek it did bring up a video, although i didn't watch it maybe tomorrow, I think you should review video.
I put in 18 oz redtek which is roughly 54 oz equivalent. Whoops I did my math wrong. I had done that conversion already when I quoted numbers.
So i retrofitted my fittings and got a pressure gauge. I took both of these photos with the system running. One shows high pressure and the other low. At one point the high side was over 250 psi. What is going on here.
Fyi the higher pressure was taken AFTER the lower, so it’s not like it’s just leaking out.
what do you mean? The compressor should stay on constantly?
Yes it should stay on.
The varying high side pressure is your radiator fan cycling on and off, this is also normal. Pressure goes high & the fan comes on, that causes the pressure to fall & the fan stops. Repeat over and over and over... all summer long.
Looks ok, go drive it.
Because you are using Redtek which does not fall under the common r12 or 134a. IDK if there is actually a pressure chart. The readings you have are too high for r12 & 134a, but the Redtek info only says low side pressure should be 32-38 psi. Don't exceed 60 psi or compressor could be damaged. Don't overcharge. The cycling switch will NOT cycle compressor at 32-38 psi. There is no high side pressure guidelines. I suggest contact Redtek with your pressure readings, and outside and duct temps and see what they say.
Because you are using Redtek which does not fall under the common r12 or 134a. IDK if there is actually a pressure chart. The readings you have are too high for r12 & 134a, but the Redtek info only says low side pressure should be 32-38 psi. Don't exceed 60 psi or compressor could be damaged. Don't overcharge. The cycling switch will NOT cycle compressor at 32-38 psi. There is no high side pressure guidelines. I suggest contact Redtek with your pressure readings, and outside and duct temps and see what they say.
do you know what pressures the system should be at? Not for redtek but according to original spec?
The cooling fan(s) should be on you need good airflow thru condenser. A/C control full cold and blower on high. High side should be 100+ outside temp is simplest way to calculate. Low side 28 -38 psi at idle at 1500 - 2000 rpm 25-30 psi duct should below 40* with r12 alteast 20* below outside temp with 134a, humidity is a factor. If its 95* and 95% humidity 40* duct temp may not happen even with a fully charged properly operating 134a system.
AC compressor won’t shut off
