I just added the 20 oz. of r134 as per factory spec. System was vacuumed and had no leaks. This is on a 2001 jeep cherokee. My gauges read 37 on the low side and 300 on the high. The air is blowing cool but should be much colder. What's going on here? Am I overcharged or is there air in the system? Any help would be appreciated. Thanks!

 

if 37 and 300 is normal, all you can do is try it again. I'm no HVAC expert though. One of the sides tubes is supposed to cold, right? That sounds like a pretty big gap in pressures though. I'd think the Hi side should be more like 200-250... unless its like 110°F where you are....

 

http://jeep-manual.ru/index.php?page=35

https://www.jeepforum.com/forum/f9/a...sures-1237591/

 

My questions are:
What was the ambient when you did this?
What was the temperature of the air coming out of the vent?
Was your electric fan running?

 

Outside air temp was 80
I don't have a way to measure the vent temp but its definitely not cold enough
I don't think the fan was running

 

Need to buy a thermometer for the vent.
Something like this.

https://www.harborfreight.com/1-inch...iABEgLTxvD_BwE

Also the electric fan not running will give a high reading on the high side.
So until you know those things for sure it is kinda hard to make an educated guess.

 

That link is for the older Renix R-12 setup.

 

DOH!

Sorry hahaha... I was at work and had a couple minutes of free time, so I didn't read it too far in depth...

 

I noticed that when the electric fan comes on the high side pressure dropped into the 200's. is that normal or an indication of a problem?

 

Could be too much oil in the system.

I'm no expert either, but if it's working but not cold enough, from what I've read either the heat can't get out (blockage in the system sort of thing) or the refrigerant/oil levels are not correct.

It might be worth it to take it to a proper A/C shop and have them flush the system completely and then put in the exact correct amount of oil and R134. If you don't have access to the expensive diagnostics/recovery/flushing equipment and are basically just guessing, it could be difficult to correct it without risking oil starvation at the compressor.

An unscrupulous person who suspected overcharge of R134 might try to blip the schrader valves to let some out... but that would be bad for the environment and possibly illegal so you should definitely take it to a shop that has recovery equipment.

 

That is normal and why I asked you if the electric fan was on.
So now with an ambient temp of 80 degrees if you are reading 37 and 200
you are pretty much in spec. In the middle on the low side, 32 to 41, and a little low on the
high side but still within spec. 200 to 260.
I would still like to know what the temp of the air is coming out of the vents.

 

The fan only stayed on for 10 seconds. Should it stay on longer? The temps seem to vary. Yesterday it got as low as 49 with an outside temp of 75 but today with the temp around 85 my vent temps were around 55.

 

Tried again with fan running longer (after a ride) pressures are 25 and 200. If I bump up the idle, the pressure drops and compressor cycles off. I took this to a shop that checked for leaks with dye and a sniffer but I feel this would indicate a low charge and a leak especially with the pressure getting lower even though the temps are higher today. This is truly frustrating!

 

With an ambient temp of 75 thinking you should be seeing around 30 to 41 degrees for the vent temp.
At 85 35 to 46 degrees maybe.
Did you take any readings at either of those ambient temps with your gauges?
Kinda need all that info, gauge reading, ambient temp, temp coming out of the vents done at the same time.
And make sure your electric fan is running when you do.
Also keep the rpms at about a 1000 when idling while doing this.

 

See my post above -fan running, outside temp 85, vent temp 65 pressures 25 and 200. I think I'm leaking somewhere as was suspected before taking it to a shop to check.