AC issues

[hockey4]

Hey all.. i need some help.

I drive a 1997 4runner. All original AC parts. I have owned the 4runner for 8 years and its been flawless. The past few summers my AC has been a little Eh... very intermittent working and not working. Well..now its summer. And when its very hot outside my compressor does not work at all. It cycles .. and when it does my truck surges very badly. My acceleration is being surged from it. But when its a little cooler like in the 70’s it works just fine. 80’s, 90’s no bueno. Freon is filled, AC fan works great . Do you think my 22 year old compressor is just ..tired ?

 

[azrex]

Does it cycle rapidly on/off/on/off? If it does, that usually a sign of either being to low on refrigerant or overcharged. If you have a set of gauges, see what the pressures are when it cycles off.

 

[hockey4]

I would say it’s cycling quickly . I’ll acquire some guages and check . Thanks

 

[JRZEE2000TR4LTD]

I would say it’s cycling quickly . I’ll acquire some guages and check . Thanks

If it's cycling quickly and it's hot out out then it most likely is low on refrigerant.

 

[hockey4]

I am not sure that its low. I filled it up last year and that’s when the symptoms started. When the compressor kicks on the truck jolts.. but only in hot weather. Just now coming home it’s around 80 and it wasnt doing it. But yesterday coming home in the 90’s it was jolting. It was freezing me out of the truck just now coming home. Yesterday - not so much. It wasn’t working at all and cycling very quickly.

I am almost thinking that its over filled.. and when it gets hot the pressure builds up too high. I used one of those generic auto part store fillers last year.

Anybody have any similar problem ? Or by chance know what the normal operating pressure should be on the high and low side during operation ?

 

[azrex]

Sounds like it's overcharged.

 

[886runner]

Is that refrigerant even compatible with a 97 system?


Sent from my iPad using Tapatalk

 

[phattyduck]

I am almost thinking that its over filled.. and when it gets hot the pressure builds up too high. I used one of those generic auto part store fillers last year.

Anybody have any similar problem ? Or by chance know what the normal operating pressure should be on the high and low side during operation ?

There's your problem. Use an AC gauge set. Pressures are highly depended on weather / operating conditions...

-Charlie

 

[azrex]

Anybody have any similar problem ? Or by chance know what the normal operating pressure should be on the high and low side during operation ?

You should be about 25-30 on the low side and 200-250 on the high side. The pressures vary depending on temp and humidity, but these numbers should get you where it's cooling pretty well.

 

[96RedRunner]

[MENTION=99893]hockey4[/MENTION], Go to page AC-3 of FSM, site glass on drier is a very useful tool since you don't have gauges. Clean the glass, with clean glass you should be able to see inside Drier clean shiny aluminium to watch flow pattern. If you see just a black hole your system is dirty, drier change on horizon, probably 22 yr old.
I use the site glass more than gauges in cases like this.
This system has a low pressure and high pressure cutout switch, sounds as your overcharged since it works better in the 70's, a higher ambient temp 80-90's causes a higher head pressure which shuts it off.

 

[drrm123]

Hav you checked the AC clutch?

 

[nissanh]

Probably an overfill. Check the glass located on top of the AC filter. If it is bubbling when the clutch is engaged it is OK, too much bubbling indicates low on freon and no bubbling indicates a properly filled system; problem is, it will stay clear when the system is overcharged too. So few bubbles coming under the glass should be close to full.

 

[mtbtim]

Some of you might find this video informative:

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