A/C pressure on IID or manifold gauges? Normal ranges?

[allegro]

I'm troubleshooting a passenger side A/C issue in another thread and wanted to document a couple general A/C questions separately as I haven't found LR4 info after searching this forum and others.

For you GAP IID users, with your A/C on "LO" mode, what's your high side A/C pressure (and ambient temperature for reference)?

If you have A/C manifold gauges, what's your low side pressure?

I just checked my pressures with gauges and IID tool and both maxed out at about 1000kpa / 145 psi on the high side, and my gauges read 200kpa / 30 psi on the low pressure side of the system. This is at 95 degrees F ambient.

I've been learning a lot more about a/c systems this week but have a long ways to go. Can anyone shed light on normal ranges I should expect to see? Does the LR4 variable displacement a/c compressor present any considerations when checking pressures, or should things correspond to the "normal" r134a refrigerant charts you can find online (sample attached)?

Thanks for any insight. A/C has always been a black box for me... and I'd leave it that way if I had a shop I trusted within a 2 hour drive!

 

[BeemerNut]

Many people go by the static pressure chart readings of air temp vs psi numbers which are the same in the system at static full charge or very low having the same psi readings. Temperature pressure laws of R134a gas.
Next they get a can with a gauge and recharge thinking all is good, they also added R134a with sealant additives this the death of any AC system. No shop will service a system with that crap damaging their evac equipment. Read the cans, larger bottles do not have this crap in it. Recharge with cans having only R134a in it NO SEALANT.

Variable compressor output, check the factory specs for this system's pressure numbers what is normal for high and low side readings.


R134a has a tight range of operation in lbs and oz. installed with a narrow under or over charge amount of specs as your AC will get warmer again being under or over charged.
Old R12 you could be under and over spec by a larger amount and still **** cold.

Best to have the system R134a removed properly (EPA ****'s to consider, wink wink) then do any repairs if required quickly not days later as air moisture is the death of AC systems internally turning to acid internally. Evaporator valve plus dryer both are cheap and this the best time to replace both before thinking of pulling vacuum and checking for leaks before recharging. Loss of oil then add same replacement anount with the correct type of oil, they are not all the same then recharge R134a to the proper amount by weight to factory spec. This is the only way knowing how much R134a is in the system starting bout empty. Big bottle deducting tare weight with the other way by adding those little (POS) 12 oz. cans which only the can tare weights are all the same but the contents vary in weight each can, weigh and marking pen on each can the contents weight then add accordingly. Several cans then take in consideration gas loss in the hose loss to air outside plus any purging of fill hose keeping air from entering your system. Big bottle solves this problem.

I purchased a two stage 3/4 Hp vacuum pump that pulls down to 48 to <50 microns max.
Three hose manifold gauge system, added a "Y" making it a four hose system easy to recharge without dirty air entering into the recharging process when exchanging cans vs bottle used.

Had a road rock damaged condenser so starting off with zero gas to recover.
POS neighbor save the flea types, I told them the R134a leaked out on the highway what's your problem? Idiots!
System contaminated hence new evaporator an dryer the normal replacement items plus the replacement condenser. With a connection and large bottles at hand besides a couple cases of 12 oz. cans and oil i'm set.

Last year serviced four family vehicles and two friends including my 95 D1 that held R134a since 10-1994 with low enough pressure to prevent the AC pump from cycling. The D1 is a pig having rear passenger AC, thinking around 3-4 lbs (?) R134a amount recharged.
Evacuated system (friend's AC business), back home recharged. Equipment investment more than paid for itself not counting future AC DIY servicing, already saved thousands of dollars.
Best part having three full 30# R12 bottles and 36 12 oz. cans R12 for the Delorean and 68 F250 AC systems long before the R12 ban BS started. The R12 bottle states,"When Empty Vent To Atmosphere Then Break Off Valve Stem". No BS this on the 30# bottle with instructions......~~=o&o>.....