Hey Guys,
Have an issue with the AC that I cant find any reference for on google or anything. Stopped at a friends house the other day and left the truck running, we are picking up some chairs, and all of a sudden the truck starts making a HORRID sound. Ill describe it as blowing 100psi pressurized air into a Duck-call, very sharp for about 2 seconds then stops. ~30 seconds later, does it again. By the third time I can the hood open, I see its coming from just behind the AC compressor pointing down and in towards the valley. It's blowing refrigerant (I believe, dont know what else it could be) out a relief valve that is back there? Lots of white-ish steam looking stuff blowing out down and into the valley. Anyways, turn off the AC, it stops, turn it on, and it starts again after a few minutes, so I just left the AC compressor unplugged for now.

Cant find any thread describing this, anyone have an idea what Im looking at?

Thanks guys.

-Andrew

 

I had the exact thing happen on my 92 last year. I turned it off for a while and turned it back on and all was well. I never did look into it because it's just not worth it on that truck. But I'm interested to know the cause

 

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Is the compressor cycling or just staying on ?

 

I think mine was cycling. It sounds like Andrews is as well

 

I'm not sure to be honest, I wasn't paying attention I was just waiting and watching for this noise to happen again, I'll get into it again and pay more attention. I'll try to get a video as well and see if I can't show it.

 

Usually is because it is overcharged from people using the little cans and filling the system incorrectly.

 

Do you have a properly working fan? At idle there must be airflow or a massive head pressure can result.

 

I hope you don't mind me hijacking Andrew.

In the case of mine the fan works.

History on the system. In 1996 the system was evacuated and recharged with r-134a. According to the decal. That's it

 

Here's my Wild azz guess and you want know for sure till its on a set of gauges.

I think you have a plugged office tube creating a lot of head pressure and a faulty high pressure switch that's not turning the compressor off causing freon to blow pass a seal.

 

Thanks guys, I got caught last night with fam jam stuff. I'll have another look today, but I appreciate the point in the right direction! Admittedly, for all the work I've done with this truck over the years, the AC system is completely to me.

 

I'm in agreement with Mike, but would add, check the condenser to make sure it is not plugged with road grime/dirt. A good air flow is a must for good AC cooling.

 

Interesting. IMO mikes thought could be the culprit. Oddly enough the a/c has been working perfectly since it happened last summer. Cycles as it should and blows icy. For me I was mostly looking to understand why it would happen. Thanks fellas.
Back to you Andrew.

 

If the high pressure switch is working properly then the high side psi should never be able too get high enough to hurt anything