Automotive Air Conditioning Information Forum

Can you guys help me to see if I can get any better performance out of my 7.3 excursion?

I have completed the following: New compressor, orifice tube, receiver dryer, Evaporator, and manifold hose assembly.

On a 97 Degree day I have the following pressures:

57 Low and 250 high.

It was vacuumed and charged by weight at 64 oz. I feel that my Low is slightly high and my high is slightly low. Is that correct? I would love to get a little colder vent temps if possible.

Thanks for the help.

Belt driven fan with fan clutch or all-electric fans to cool the condenser??? Assume dual AC, so was that front evaporator replaced?

I replaced the front evap.

It’s a belt driven fan.

I haven’t ever had issues with the truck overheating. But it’s possible the clutch is weak?

hbabler wrote:It’s a belt driven fan.

I haven’t ever had issues with the truck overheating. But it’s possible the clutch is weak?

Weak fan clutch can fail to cool condenser properly but still not overheat. Do a search for fan clutch testing.

Thanks,
Wouldn’t a bad fan clutch give me high pressure side readings?

hbabler wrote:Thanks,
Wouldn’t a bad fan clutch give me high pressure side readings?

Depends on the refrigerant level.

What does the vent temp look like? Are these pressures at idle?

Vent temp is about 60. The pressures don’t seem to change much at a faster rpm. I forgot to write the ones at at 1500 rpm down.

The truck is getting a new turbo this weekend and when it’s running again I’ll check the pressures at 1500 rpm and report back.

Thanks for the help. I just want as much performance as I can get out of this AC it never seems to be cool enough at idle or around town.

hbabler wrote:Vent temp is about 60. The pressures don’t seem to change much at a faster rpm. I forgot to write the ones at at 1500 rpm down.

The truck is getting a new turbo this weekend and when it’s running again I’ll check the pressures at 1500 rpm and report back.

Thanks for the help. I just want as much performance as I can get out of this AC it never seems to be cool enough at idle or around town.

You can also mist the condenser with water and see if pressures and temperatures drop, a sign of insufficient cooling of the condenser.

it never seems to be cool enough at idle or around town.

A telling bit of information there. Increasing vehicle speed moves more air over the condenser.

A full load test at 1800+ engine RPM with the cabin fans on high and the doors open will show you worst case pressures & temperatures. Run that way for 90 seconds to let the system stabilize, and take pressures & vent temp while at high idle. Record the ambient temperature as well.

How long have you owned this truck?