Mechanics

MODELS AIRCON STOPS WORKING AFTER ABOUT AN

1994 Toyota Other

Air Conditioning problem
1994 Other Toyota Models 4 cyl Two Wheel Drive Automatic 130km miles

i have a 94 toy hiace super custom van import that has dual air con but 1 compressor and has been faultless for 2yrs till now, the front air con is mostly working on cold days for about an hour then it dies off, yet if I turn the back one on its always 100% fine. To get the front working again I need to park up for a couple of hours. If I leave van out in the hot sun and then turn aircon on the front one wont work but back one is still fine.
i have found evaporator and washed it and the drain is not blocked and I dont think it ices up. I have found that there is water draining when working but stops leaking when in faulty state, rear drainage always works, if front air con only is used and is in faulty state I believe the compressor stays on, also I dont see anything in the little gas glass window next to the drier
hope this is enough info and not to confusing
many thanks
jay
Avatar
Jaydamuss
January 27, 2010.




Hi
Need High and Low side pressure readings for diagnosis but suspect expansion valve faulty stoping flow of freon into evaporator. Feel inlet and outlet pipes from evap. Before and after it quites.
Let me know
Thanks for donate

Docfixit
Jan 27, 2010.
Ok I went out and bought a manifold and tried to do some tests, all aroundabout measuring as im learning,
when working: a/c turned off 55/180, with a/c on no revs 40/240, with revs 30/250 and I think this was the same readings with the rear on or off.
When faulty, (i forgot to touch expansion) 25/250, 5/200 with revs, 25/250 with rear a/c on.
It was a hot muggy day today and had done about 1 and a half hours driving with it on full when it lets out a bit of frost out of the vents and then warms up.
Hope this helps a bit more

Tiny
Jaydamuss
Jan 29, 2010.
Sorry forgot to mention that the van is r134a system
thanks

Tiny
Jaydamuss
Jan 29, 2010.
Ok when it went faulty today the hot pipe was warm and cold was coldish but the a/c was colder than warm air like it was just hanging in there, but I noticed when I put the rear on the hot pipe was room temp and also the cold one was the same but the front a/c got warm, does it seem to have a lack of gas in the system?
Thanks

Tiny
Jaydamuss
Jan 30, 2010.
Reading indicate stuck expansion vale need to pull evaporetor box out from under dash to access. System will need discharged and new drier installed. Also system needs to be vacuumed down for coulpe of hours after repair. Added about 2oz. Oil to receiver drier.

Docfixit
Jan 30, 2010.
Thanks for you advise, I had the the joy of replacing the valve and drier, and got an ac tech to vacuum oil and regas 1100gms r134a and has been working excellent, the new pressures are with revs 54/300, would these readings mean a bit too much gas?
Thanks again for all your help

Tiny
Jaydamuss
Feb 16, 2010.
Yes 35-40/ 220-240 is where you want. What is ambient air temp? Condensor clean fans good?

Docfixit
Feb 16, 2010.
I have rechecked this morning and readings seems to be more normal now on a cooler day 35/250. The other day when the air con guy was here, it was 40C and was a very hot humid day, so I think the vehicle is good and working fine, many thanks for all your help. Jay

Tiny
Jaydamuss
Feb 16, 2010.
Good news that is excelent readings
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Docfixit
Feb 17, 2010.

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