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92 240 AC Rebuild

I also forgot to mention the expansion valve replacement?

There is little to anything available online. Could anyone give me some info in more detail?

I know the evaporator will have to be taken out to replace the expansion valve.

'92's don't have an expansion valve. The systems were changed over to an orifice tube system in '91.
 
'92's don't have an expansion valve. The systems were changed over to an orifice tube system in '91.

+1 and they are very easy to change and cheap. I would replace it the same time you replaced the R/D because I think it is right there next to it. At least on the 740s it is.
 
Can anyone recall orifice tube location on the 92 240?

Also still looking for hi and low pressure acceptable ratings

Thanks
 
Low you want 30-40. High you want about 150.

Static is about 60 psi on both. The compressor kicks on and, if it's working, the low side goes down to 30-40 and the high should go to at least 150.

I use a machine to get the proper weight in there. And to WEIGHH what came out.
 
Low you want 30-40. High you want about 150.

Static is about 60 psi on both. The compressor kicks on and, if it's working, the low side goes down to 30-40 and the high should go to at least 150.

I use a machine to get the proper weight in there. And to WEIGHH what came out.

Pressures are based off of ambient temperature, but those are well rounded Ball Park numbers.
 
Can anyone recall orifice tube location on the 92 240?

Here's pictures of the AC parts from a '93 240 (click on pic for full size)


Orifice tube is on the paper towel, and goes into the frame rail end of the line that goes to the lower bulkhead connection to the cabin evaporator.
 
Hey All,

Serious question. So i know when vacuuming both low and high pressure knobs should be open on the gauges. But what about when putting freon in the system.

I know during r134a filling the low gauge should be open, what about the high gauge knob? Should the high pressure side be closed during filling?

Thanks
 
I know during r134a filling the low gauge should be open, what about the high gauge knob? Should the high pressure side be closed during filling?

Charging is normally done on the low side but from a technical point of view it doesn't matter with the engine off. I probably wouldn't open the high pressure side simply because its an opportunity to screw up and forget and start the engine. That wouldn't be a good thing to do.
 
Hey All,

Serious question. So i know when vacuuming both low and high pressure knobs should be open on the gauges. But what about when putting freon in the system.

I know during r134a filling the low gauge should be open, what about the high gauge knob? Should the high pressure side be closed during filling?

Thanks

Yeah charge from low side only. High side closed on the manifold, but open on the hose (so you can read high side pressures). Charge with the can upright if possible, as you do not want to feed the compressor pure refrigerant in liquid form. It’s very helpful to have a blowdryer to heat the can up, increasing pressure differential. But obviously don’t make it hot hot. Just don’t let it be cold.
 
Yeah charge from low side only. High side closed on the manifold, but open on the hose (so you can read high side pressures). Charge with the can upright if possible, as you do not want to feed the compressor pure refrigerant in liquid form. It?s very helpful to have a blowdryer to heat the can up, increasing pressure differential. But obviously don?t make it hot hot. Just don?t let it be cold.

I understand what you mean on the hose having the gauge open. But what do you mean closed on the manifold??

So when filling refrig have the cog handle open for low and high closed when car is running so pressures can be read safely??
 
I understand what you mean on the hose having the gauge open. But what do you mean closed on the manifold??

So when filling refrig have the cog handle open for low and high closed when car is running so pressures can be read safely??

Yes, you are using manifold gauges right? The part that you hang off the hood from the hook is called the manifold. On the manifold you have blue (low side) and red (high side). During vacuuming I leave both sides open on the manifold (counterclockwise to open on my gauges) because it vacuums a bit faster and from both sides of the system.

Then when filling with the car on, fill low side only, because ones the compressor kicks on, high side pressures will exceed pressures of the can and low side, which means it will not charge. Or not easily/safely at least. With the vehicle OFF, you can charge from both sides, though I don?t see the point.
 
I went through the same thing on my '92. Hopefully I can save you time.

The big obvious fitting is for a propietary Volvo connector that you should ignore. The real low side fitting is on the receiver/dryer itself, probably with a plastic cap on it. The adapter you bought should fit on it, but it will be tight to connect everything up against the firewall.

I never found the high side but successfully charged my system with just the low side connected and got working AC.

I currently have the radiator out and found a fitting on the refridgerent lines that run under the condenser that looks like a good candidate. Easiest access would be from underneath the car
 
Ok thanks for clarifying.

Dumb question but when filling refrigerant and the high pressure side is closed on the manifold will a reading still come up?

I would think not with the manifold gauge being closed. Isn't the the high pressure reading just as important as the low even when filling refrig??
 
Ok thanks for clarifying.

Dumb question but when filling refrigerant and the high pressure side is closed on the manifold will a reading still come up?

I would think not with the manifold gauge being closed. Isn't the the high pressure reading just as important as the low even when filling refrig??

Yes the high side will still read with the manifold closed. But you must make sure the portion connected on the high side line is open though.
 
To clarify, both gauges will read pressure when they are hooked up to the system whether the valves are open or not. Keep the high side valve closed anytime you are working with a pressurized (filled) system.
 
Thanks!!

Hey all so I have another dilemma. My receiver/dryer on the car has a switch/sensor built in with the low pressure port and hoses.

The R/D i bought does not have the switch built in and i am not seeing ones online being sold this way.

Is this apart of the old R12 system? Is there any way I can still us the R/D i bought and do something else with the switch?

I really want to go ahead and use what I have instead of buying another R/D. I'll leave pics

https://ibb.co/hyc1qhc
https://ibb.co/WH826SX
 
Thanks!!

Hey all so I have another dilemma. My receiver/dryer on the car has a switch/sensor built in with the low pressure port and hoses.

The R/D i bought does not have the switch built in and i am not seeing ones online being sold this way.

Is this apart of the old R12 system? Is there any way I can still us the R/D i bought and do something else with the switch?

I really want to go ahead and use what I have instead of buying another R/D. I'll leave pics

https://ibb.co/hyc1qhc
https://ibb.co/WH826SX
Are you filling from the R/D r12>r134a adapter? I believe the thread pitch is the same for the low pressure cutout switch. Might be worth buying another? All of mine have had the correct fittings. Even the dirt cheap ones on amazon.
 
Hmmmm...yea dammit you are right. I guess I will get another and try this again lmao :rofl:

Amazon is quite interesting these days.
 
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