2002 S60 Refrigerant High or Low pressure?

sergio · Post by **sergio** » 04 Jun 2014, 06:15

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Time to refill the refrigerant. Vida-Bible says "ONLY on the HIGH pressure side"
Yet all You Tube clips and others say "Low pressure side"
So which one is it?
Would the gauges that come with some kits or that are sold separately give an incorrect reading if hooked to the High side?

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Post by **jimmy57** » 04 Jun 2014, 06:49

Charging with a charging station is done with system off through high side.
Partial charging using the can n hose is low side. The high side pressure is above the burst pressure risk level for a can with it running and system static pressure equalizes on both "sides" of system and is the same pressure as the can if the system has 15% or so of full charge. No refrigerant in-flow would occur with the pressures balanced.

The can n hose charge kits have the fitting that only fits the low side. The service fittings are purposely different sizes on systems with R134a refrigerant (any car not older than a 1993 for Volvo and 1994 for others).

sergio · Post by **sergio** » 04 Jun 2014, 22:00

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So what you're saying is that since Vida says use High pressure and that Can n Hose goes only to the low pressure end, I shouldn't do it myself and take it to a pro. Right?

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Post by **JDS60R** » 04 Jun 2014, 23:59

Sergio,
Its ok to charge on the low side. Jimmy said its best for partial charges. So if you are topping it up the low side is fine.

Post by **jimmy57** » 05 Jun 2014, 06:55

A little background here: adding refrigerant is not approved by any car manufacturer. Charging station equipment allows the refrigerant to be collected and the right amount replaced so you have the correct amount in system with no guesswork. The charging station pushes refrigerant in through high side with engine off/compressor not running. If you look at the repair info from the manufacturer adding refrigerant will not be mentioned other than as testing tool.

You don't have a charging station so you have to add through low pressure side service fitting. The low side pressure (unless there is a problem) will be much lower than pressure in can so the refrigerant will flow into system without the need for the charging station equipment. The fittings on high pressure and low pressure parts of the system are different and the DIY charge kits only have the low side coupler. That is done for safety reasons. You can readily rupture a can by having the high pressure side connected and having the pressure go from car into the can and exceed the burst pressure of can. The can does have a pressure relief blow out feature so that the can doesn't explode dangerously but it will open and dump your refrigerant anyway if this were to occur.

Yes, you add through low side service port with engine running at high idle (stick on accel pedal) in increments so you can monitor temp out vents until it cools well. This slow incremental approach keeps you from overcharging the system.

Post by **marshallh** » 05 Jun 2014, 11:28

Like others said, the refill kits you can buy at Autozone are only designed to go on the low side. The fittings are different sizes (the low side is larger) so you don't blow anything up.
If your system is too low, adding more refrigerant will hide the problem for a while. However, the system needs a certain amout of a particular oil in the refrigerant; that's how the compressor is lubricated. If the leak has gone on long enough you could be low on oil, and accelerate the wear on the compressor. I've seen this play out among various cars.

Refill refrigerant > low on oil > compressor wears > 2-3 years later, it dies > you buy all new A/C system equipment anyway.

It really is worth it in the long run to take it to a shop with the proper AC equipment who will fill it with UV dyed refrigerant to actually find the leak, and then you can fix it properly before they pull a vacuum to remove accumulated moisture, replace the filter drier, and recrhage the system with the proper amount of refrigerant and ratio/type of oil.

There are several ways to bandaid the problem, but only one way to fix it for good.

Post by **abscate** » 05 Jun 2014, 11:56

If you haven't had a catastrophic leak, you probably have not lost much lubricant from your AC system. The rcvr/drier will end up holding most of it and its pretty hard to lose it from there.

If you are adding more than a can per season, then I would worry about the PAG oil, otherwise you are probably fine.

sergio · Post by **sergio** » 07 Jun 2014, 18:03

Thank you all for the feed back.
Reading you I learned what is what and where and how to refill the refrigerant.

So, I went out and bought a kit and drove home hoping to spend few minutes with the car.
When I started the car, surprise , the A/C started to pour cold air out!!!!
Alas it lasted until I turned the engine off. Then It wouldn't kick in anymore.
This afternoon I checked the compressor (engine idling, A/C set to max, fan set to max) I touched the face (side?) of the compressor with a stick. It doesn't seem to be turning.
I remove and re-inserted the relay for AC clutch; no change.
I checked with Vida, I get a ECM-5000 A/C pressure sensor - signal too low
So;
Is it that there is no refrigerant in the system? (then why did it work for 1/2 hour?)
Or the sensor needs to be replaced?
Or the compressor is faulty / dead?
Is there anything else that I can think of?
How to find the real reason?
Thank you.

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Post by **abscate** » 07 Jun 2014, 18:37

Clutch gap problems are common on these cars. Search ' bread clip fix' for discussion

Post by **marshallh** » 07 Jun 2014, 20:09

The compressor will be disabled if the refrigerant is too low, again because the refrigerant carries the oil. Cutoff on my other car was around 5-6psi.
However if it has gotten so low in such a short time, you may have a very serious leak.

One workaround I did was to pop the cover off the A/C clutch relay and squeeze it by hand to activate the clutch, while I opened up the valve on the R134a can. (The compressor failed a while later anyway)