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Ford Ranger return line sweating profusely

hossbuilder on Sun October 12, 2008 12:03 PM User is offline

Year: 2000
Make: Ford
Model: Ranger
Engine Size: 2.5 L4
Refrigerant Type: 134A
Ambient Temp: 80
Pressure Low: 50
Pressure High: 210
Country of Origin: United States


I have a 2000, Ford Ranger with a sweating return line. The entire circuit from the evaporator through the receiver / drier back to the compressor is sweating so much that it is leaving a discoloration on the hood. I thought I had a coolant leak and then realized it was the A/C.

I tried adding a can of 134A. The pressures went to 70 / 325 for awhile and then dropped back to 50 / 210. It seemed the sweating lessened when the pressure was high. I have a cabin air temperature of 62 degrees at the vent during idle. I noticed the compressor clutch stayed engaged the entire time I was working with the charge.

Any suggestions anyone can give me would be appreciated.

Am I over charged? Under charged?

orifice OK? Compressor OK? Pressure Switches?

Where should I start?


Dougflas on Sun October 12, 2008 1:15 PM User is offline

You should now start by recovering the charge and weighing in the proper charge. I don't follow where yoiu said that the lines (suction) are sweating and discoloring the hood. The suction lines will sweat depending upon the ambient dew point...perfectly normal. We need temps and pressures at 1500 rpm and the doors and window open. Then give us the vent temps with the doors/windows closed.

chris142 on Sun October 12, 2008 5:16 PM User is offline

It sounds like it was working fine then you added refrigerant and screwed it up. Definatly need to remove whats in it now, vacuum and recharge with a scale.

If you put the blower on low does the compressor cycle off and back on ocasionally?

mk378 on Mon October 13, 2008 11:43 AM User is offline

These lines normally get as cold as the air inside, thus they will sweat. If that is causing a problem, once you have the system working properly again, you can apply insulation to the lines to reduce sweating.

Edited: Mon October 13, 2008 at 11:45 AM by mk378

hossbuilder on Tue October 14, 2008 6:08 PM User is offline


First of all thanks to each of you for weighing in and for giving me good information.

You probably have figured out I am a back yard hacker with limited equipment. I have a gauge set and a vacuum pump that is it.

My problem was not so much that it doesn't cool but rather that the suction line which has a pipe that goes around the front of the engine sweats so much that it washes the dirt off of the engine and the fan blows it up unto the bottom of the hood. After adding some refrigerant, I have been driving the vehicle. I also covered the suction line with pipe insulation like you would use on a sweating water pipe. The covering pretty much stopped the sweating problem.

I have my thermometer inserted in the center vent. It shows temps from 55 to 60 while driving in mid 80 ambient temps.

I will check my clutch to see if it is cycling. I don't think it is since I added freon.


Dougflas on Wed October 15, 2008 8:38 PM User is offline

You're probably overcharged. You need to recover the charge, pull a proper vacuum, and recharge the proper amount of refrigerant into the system. I don't mean this to sound negative but with your limited equipt and experience, this is the only way you can determine the proper charge.

chris142 on Wed October 15, 2008 9:18 PM User is offline

Make sure that your heater control valve is not letting hot water into the heater core when the AC is on.

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