• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

240 Air Conditioning Retrofit

I have a 1000 CFM deal ready to drop in.

Finally got the pre-fill bugs sorted. System is vacuumed, oil is charged (7.5oz of ester), compressor clutch is verified working. We did run into a snag when we realized that there is no high side pressure port for a gauge.

So, now what?
 
Good reason to charge by weight.

Another port can be added if you are going to test by hi/lo pressure/temperature readings.
 
I forget if you have a full '93 system or a converted '91/'92, but either way, you want to fill by weight since Volvo didn't provide a factory high-side port. I'm also not sure if ester oil is the right choice, I'm not an A/C Tech.

Posts on this site say 1.62lbs r134a, or do some searching for fill capacity, e.g.
https://www.techchoiceparts.com/refrigerant-and-oil-capacities/volvo

You'll need 3 12oz cans, a screw on can tap, a manifold gauge set (just the can and low pressure hoses connected), and a scale that you trust. Weigh the cans before and after to see how much has gone into your system.

When I charged my '85, w/ a full '93 swap, I needed to warm up the cans and rev the engine some to get it all in. Otherwise, at idle, the compressor was always engaged but didn't drop the low side pressure enough for the cans to empty. Also, check the accuracy of your scale beforehand. My cheapo kitchen scale varied by a few tenths of an ounce depending on how long it had been on and the phase of the moon.
 
I decided to go with Ester over PAG 46 because the person that sold me the evaporator could not confirm whether it was a 91 or 92/93 one. Either way I flushed it with acetone and let it dry. Just want to avoid potential problems if possible.

Good call on filling by weight. Will do that.
 
OK, filled by weight as best as we could, while maintaining a low side pressure of 30-40 PSI. Only found self-sealing 12oz cans of refrigerant but could not get the can tap adapter to work without leaking a significant amount of R-134A. Vents blow at ~54*F with a cowl inlet temperature of ~95-100*. Asked Gary about it and he suggested pinching the heater hose...made no difference.

I think I'm going to take the car to an AC shop to get the charge dialed in. Hopefully they would be able to evacuate as well as fill it to dial in the right amount of refrigerant.

Either that or the charge is totally fine and what's screwing me turns out to be the suction line being 1" away from the turbine housing of the turbo. There is gold foil tape and a turbo blanket to mitigate, but I don't know quite how effective those are.
 
What temp do you get with the system in recirculate?

The factory specs for my 82 is 48 to 54 degrees. Mine runs at about 48 degrees in recir.
 
Close . . . no cigar.

A vacuum and recharge by weight might make a few degrees difference but you are a long way from the 30's. A pusher fan that runs whenever the AC clutch is engaged will help but only a few degrees.

I know it has been mentioned but a little leaking temperature valve in the heating system can easily overcome the best AC systems. I have installed a shut off valve in the heater hose in a couple cars.
 
A good fan and air guides will help get the high side pressure down a lot.

A good compressor and a clean/proper working TXV is also crucial.

I use a machine to put the proper WEIGHT.
 
Last edited:
Harlard said:
My garbage uses an orifice tube/dryer system...
Click to expand...

Nothing wrong with that. Im using the orifice tube in my 93 and Im getting mid 30's at the vents. I would get rid of the ester oil. You need pag 100 or something. Take one of your high side hoses and have a port put into it.
 
Harlard said:
Vents blow at ~54*F with a cowl inlet temperature of ~95-100*.
Click to expand...
That sounds pretty good to me if you're running without re-circ. I don't think my retrofit will drop the incoming air temp by 40?-45? on a hot day (but I'm worried that my '93 salvage yard compressor isn't doing so well).

What's the official test procedure? Re-circ or cowl inlet? Windows cracked? Idle or highway speed? Fan speed? Looking for mid 30s center vent temperature, or XX? drop from outside air?

Edit: is recirc working? Stick your head in the passenger footwell with a flashlight and see if the big flap on the front of the air box opens/closes correctly.
 
This was side vent qith car idling in the garage. Recirc works, I redid the entirety of the under-dash area when I replaced the passenger side panel

As for ester oil, the performance difference is negligible at worst. I'm not flushing and redoing the whole thing just for that.
 
For anyone looking to replace the Accumulator to compressor line on a 93 240, the one you cannot get anymore, I found the line from a 94 940 will fit and the fittings match.

It runs a different route from the accumulator, under the engine and back up to the compressor, and the 940 must be a little wider so you have to tweak it a little, then insulate some parts that may rub, but the hose fits, and it's available and cheap.

Presumably they were wanting a lower hood line on the new design, hence the different route.
 
You must log in or register to reply here.
Back
Top