Automotive Air Conditioning Information Forum (Archives)

westcreek on Sun July 03, 2011 9:09 AM

Year: 1997
Make: Tractor
Engine Size: diesel
Refrigerant Type: r134a
Ambient Temp: 100
Pressure Low: 350
Pressure High: 150
Country of Origin: United States

New to forum,

Please help. My tractor AC quit working. History - AC wasnt cooling, so checked it out and put new thermostat in (old one was broke), evacuated system for 2 hrs, added 4 cans of refrigerant using gauges till low pressure was at 55 psi. and everything was great for about a week. Ice cold air. Then one day warm air. Then cold air intermittently. Compressor kicks on then off. When it kicks on the air is cool. Checked gauge readings. Low pressure was 350 psi and high at 150. Checked fuses. One for low and high pressure switch (which is on drier) and condensor fans was blown. Checked fans and one locked up. Unplugged bad fan and replaced fuse. Restarted engine and tried again. good fan not running, relay working, gauge readings were - low side pegged out on psi and high side at 125. Let engine cool overnight. Checked pressures and low side at 60ish and high at 125. Started engine and air was cool for 5 minutes, then compressor started cycling again. Low pressure side high again with no condensor fan running. Forgot - expansion valve equipted.

Thanks in advance,

JJM on Sun July 03, 2011 2:13 PM

You need properly working fans... replace the bad one and post back... or you might not need to as problem will likely be solved.

Joe

When considering your next auto A/C purchase, please consider the site that supports you: www.ACKits.com

westcreek on Sun July 03, 2011 2:30 PM

Thanks for fast reply. I have new fans on order. Will post back when installed and tested.

mk378 on Sun July 03, 2011 4:02 PM

Also clean out the fins on the whole heat exchanger stack: condenser, oil coolers, and radiator. Tractors constantly get clogged with dust and plant matter. The A/C performance will be the first to suffer-- long before the situation is so bad that the engine overheats.