Engine/Transmission (1994 - 1998) adding refrigereant

[Stmpplr]

I need to add refrigerent to my AC system. I'm pretty sure it goes in the low pressure side, but am not sure which valve that is. Both are on the passenger side, one up near the battery, and the second is lower in the general area of the oil filter. Which one do I use?



TIA.

 

[hsmith]

The one near the battery is the low side. The charge hose will not fit on the high side valve by the filter. Different sizes.

 

[kenny61]

he charge hose will not fit on the high side valve by the filter. Different sizes.

Yup it only fits on the low side

 

[DieselDoghouse]

Yep - you want to add GAS to the low side (adding liquid by inverting the bottle supposedly does nasty things to the compressor). If you use a three-hose manifold be careful not to open the red valve to the high side—will introduce high pressures to the refrigerant canister and that could be BAD!! Also supposedly always add charge when compressor is running.

 

[kenny61]

Yes system must be running. if it is empty and the compressor will not start jump the low pressure switch

 

[Skydiver]

Stmpplr, Please tell us why you need refrigerant? Have you cleaned your condensor?

I bought a nice american made set of r-134 gages 2 years ago. While I had my (Dodge) system hooked up I noticed the low side pressure would rise when I increased rpm from 1000 to 1500. Never seen that.

My son works for an Air cond company. He said R-22 and R-134 will be hard to find in the near future. I think I'm fixin to buy 30 lbs of 134 ($265). I bought 2 30lb jugs of 12 back 18 years ago and doubled my money. People will give up their first born child to get their Air cond fixed. LOL



I took Air cond/refri in trade school about 31 years ago,,, before compressors were invented.

 

[Stmpplr]

A little more looking and I find that the clutch is not engaging. One of the flat arms in the center is split at that hub bolt, so I need a new clutch at least. Where is the low pressure switch to jump as mentioned above? I assume there are some electrical gremlins that could prevent the clutch from engaging. I swapped the relay out with a known good one; no change.

 

[ttbird]

The low pressure switch is on the drier, which is against the fire wall on passenger side of engine compartment. Near where your heater hoses go thru fire wall. I usually just unplug wire and use a paper clip straightened out to jumper plug. Is a two wire plug on top of the drier.