This past Friday after 2 hours shopping for school clothes. We got in our 2000 Exp and it didn't want to cool off. We rolled the windows down as we were driving off and I could hear the compressor bleed off some pressure a couple times, after that it started to cool. It was only 87F. Prior to that I noticed(2 months now) it cooled down kind of slow at times when amb. temps are in upper 80s and higher I bought a can with the gague and noticed it had 70psi on the low side so I didn't add it. The system has never been messed with since we bought it new. Not sure if the where the restriction would be for the abnormal low side readings. I bought some gages and yesterday pulled the following readings:

Morning in Garage: High-105psi/Low-85psi

2min after started: High-230psi/low-87psi
(AC-Max High)

2min after shut off: High-75psi/Low-84psi

After 10 min Drive: High-70psi/Low-67psi
(System shut off)

After 10min Drive: High-205psi/Low-39psi
Amb Temp-88F, Vent Temp-40F

After 5min Idling: High-220psi/Low-35psi
Vent Temp-50F

After 10min Idling: High-225psi/Low-35psi
Vent Temp-48F

10min after shut off: High-85psi/Low-80psi

 

I take it the Comp. is cycling on and off on a warm day?
If NO, it is not, disregard the following!!!!


It sounds like it may be a little low on gas.
At high idle, A/C on max high fan, windows down, you need about 42lbs psi
on the low side.

 

No, the comp is running and cycles normal - really only cycles during cruise as a light that comes on when the electric fan is powered which is relayed from the compressor.
Thanks

 

You may indeed be experiencing some partial restriction. If you don't know about working on A/C, don't do this, have it done by a pro. The A/C system needs to be discharged, opened, remove and inspect orifice tube. The intake sceen on the o-tube will probably be dirty. Disconnect all hoses, remove accumulator, drain oil from compressor, Flush out the condenser, Evaporator, and hoses. Put on new accumulator. Put new oil in compressor, condenser and accumulator, about 8 oz total, check your specs. Connect all hoses and everything with new o-rings. Evacuate system with Deep Vacuum. Charge in proper charge of refrigerant. Clean the Condsensor and be sure the fan blows a lot of air thru the condenser. You should be back to good preformance.
Good Luck,
E.D.

 

I had some experience on old F150s and 80-90s 5.0 Stangs. Everything was pretty easy to get to. This thing seems to be a little more involved with the unfavorable access to the accumulator. I already bought the orifice tube and a motorcraft accumulator. I will probably tackle this job early saturday. Since I will be flushing out the system and replacing the oil in the compressor, I was contiplating going to R12 for improved performance. I have about 20lbs left in a 30lb tank. I would just need to go with mineral oil instead of PAG. What are your thoughts?
Thanks,
Rob

 

Freeze 12 will give you better performance than R-134a and it made right in your area.
It will run at a lower pressure and give better cooling. It is also safe for the environment.

 

I actually put that in place of the R134s that was in my 90 Towncar. I would have went back to R12, but didn't get the r12 cylinder about 2 weeks after I put it in. The Freeze 12 does cool better than R134s, but now that I have R12, I'm thinking of going back to 12 in it. Also found Freeze12 for $7/can in Houston on 45S near downtown.

 

Don't expect any A/C shop that doesn't have a dedicated Freeze 12 recovery machine to service your system now if/when it ever needs it.

 

I didn't plan on using it on the Expy. I do have it in my 90 Lincoln. I was thinking about going R12 in the Expy since I was flushing everything out.