Adding a high pressure port to 93 240 AC

volvodriverman

Anybody ever done this? I've adapted the entire AC system from a 93 240 into the GT and there's no high pressure port but there is a plugged port in the back of the original compressor. Should be right to find an adapter to thread in with a R134A quick connect yeah?

carnut222

volvodriverman
Anybody ever done this? I've adapted the entire AC system from a 93 240 into the GT and there's no high pressure port but there is a plugged port in the back of the original compressor. Should be right to find an adapter to thread in with a R134A quick connect yeah?

I'm a bit confused...if you adapted the 93 AC system into your GT (which is what I did as well on my 79 245 project) did you not transfer over the entire AC system, including compressor, all refrigerant lines, the receiver/drier, etc, from the 93? If so, does it (the 93 AC system) not have a high pressure port? Sorry for my ignorance.

volvodriverman

Correct on all levels. It appears with the upgrades circa 91 to 93 Volvo did away with a high pressure port.

carnut222

volvodriverman
Correct on all levels. It appears with the upgrades circa 91 to 93 Volvo did away with a high pressure port.

Ahh, so what do you need the port for? Is it just for measuring the pressure as you fill the system? The guy who re-gassed mine didn't mention any issues when he filled it after I did the conversion.

Ex850R

It's done by mass anyway isn't it?

Each system is rated different weight as to capacity cos the product is so volatile to expansion (I could be making that up....)

carnut222

Ex850R
It's done by mass anyway isn't it?
Each system is rated different weight as to capacity cos the product is so volatile to expansion (I could be making that up....)

Correct...but I guess you could run into problems if you mix and match components. But in the case of the original poster's conversion and mine, we used all the 93 bits, so in theory we can use the mass quoted on the 93 refrigerant label.

Ex850R

Does anyone here do their own with the little can kits I've seen used on YouTube?

carnut222

Ex850R
Does anyone here do their own with the little can kits I've seen used on YouTube?

I think that's more of an American thing where you can pop down to Walmart and buy a can of gas to top up your system. Not allowed in AUS as far as I know as you can't buy the gas easily.

volvodriverman

I'm switching over to hychill and it's a different weight to R134A.

The missing port is to measure the high pressure side and I'd sooner be able to see what's happening than not! That said Volvo says to just fill X weight and call it good after a good vac of the system.

carnut222

volvodriverman
I'm switching over to hychill and it's a different weight to R134A.
The missing port is to measure the high pressure side and I'd sooner be able to see what's happening than not! That said Volvo says to just fill X weight and call it good after a good vac of the system.

Yeah the Hychill would be different probably. Is there a reason you're not using R134A? My 91 240 wagon (originally R12) has Hychill in it. It freezes up so you have to cycle the AC system on the freeway. On the 79 (using the complete 93 R134A system, with R134A gas) it works as intended.

volvodriverman

carnut222
https://ozvolvo.org/discussion/comment/217066#Comment_217066
Yeah the Hychill would be different probably. Is there a reason you're not using R134A? My 91 240 wagon (originally R12) has Hychill in it. It freezes up so you have to cycle the AC system on the freeway. On the 79 (using the complete 93 R134A system, with R134A gas) it works as intended.

Being more efficient at lower pressure hence less stress on the entire system is the main reason. I've run it in an earlier 240 R12 system and it was spot on, no sign of freezing up. Maybe yours is a little under charged? I'm no expert, learning as I go here!

carnut222

volvodriverman
https://ozvolvo.org/discussion/comment/217067#Comment_217067
Being more efficient at lower pressure hence less stress on the entire system is the main reason. I've run it in an earlier 240 R12 system and it was spot on, no sign of freezing up. Maybe yours is a little under charged? I'm no expert, learning as I go here!

The nice thing about the earlier systems is you have the thermostatic control knob so you can set it to cycle frequently on the freeway. The later system just has the on-off switch so it relies on the system to tell it when to switch off. Maybe my 91 has a bad thermostat so it's not switching off the compressor before the evaporator freezes up? I don't know. I do much prefer the rotary AC knob as you can dial it in to a decent temp and it automatically cycles more or less frequently, instead of blending in heat (seems wasteful) or switching the AC rocker switch on and off.

Slowbrick

I'm also going to encounter this as I've fitted a 91 system to my 77. I remember when I had R12 in my 240 the mechanic would have a Hychill bottle on scales and would fill it by weight. The AC in that car always seemed to work great so he was doing something right!

volvodriverman

Just gassed it up to the specified weight and it's blowing nice and cold. According to hychill a 93 240 uses 750g R134a and 230g hychill and a 91 to 92 240 uses 1105g R12 and 330g hychill. So far so good.