Waiting for my vacuum pump, so will have to try again tomorrow. Thinking of flushing the condenser, and maybe the whole system. Factory oil charge is 7 oz., that is what I installed with the new compressor 3 years ago. Starting to worry about the accumulator, I know you are supposed to replace every time the system is opened. I'm in Utah, and the air is dryer than a popcorn fart, so i wonder how much moisture the accumulator would soak up in the limited time that it is exposed. Also has anyone used a variable orifice tube? Would a variable tube be a good choice for the Salt lake area? We are expecting near 100* heat every day this week.

 

I have never used the variable orifice tube disconnect the lines going into the accumulator and the dryer. Used the pressurized flush solution you can get at most autparts stores(usually a littel less than $20 per can) also remove the orifice tube. Flush the crap out of the condenser and evap. Install new orifice tube. Hook up refrigerant lines to accumulator and dehydrator. if you do not want to replace the accumulator then pull it out of the truck and flush it also. hook uo your vaccum pump and pull vacuum. Once the suction gage reads 30" vacuum ( yes I know it is impossible to pull a perfect vacuum, but the gage will read 30") i would let the vacuum pupm run for at least another hour. isolte the system so the gages still read system pressure but isolate the vacuum pump. Mark needle position on gage face. Goi eat lunch. come back in 30 minutes to see if you have a vacuum loss. If no vacuum loss charge system, if you have vacuum loss, find the leak.

The reason to pull the vacuum is to remove moister and air and non condesable gasses from the system.
The reason it is recommended to replace the accumulator is that it is a source for contaminants to remain in the system, which can then later get into your compressor and damage it.

When you charge the system try not to introduce air into the system through the charge hose.

Good luck

matt

 

Big difference between industrial and automotive applications. I always consult the manufacturer's documentation to see what they designed the system to run at. It is my choice the push the limit if the need arises

 

Great words of wisdom and experience here.

 

The accumulator should be fine, if you left a line off for a day or so then I'd be worried about the desiccant inside. IIRC water boils at 70* at sea level at 29.13" of vacuum. I always tell the people at work that you can never evacuate a system too long. Be sure to add some dye to the system for future leak detection should the need arise.

 

Well $50.00 later and I'm no better off. Took everything apart, flushed, new seals, new orifice tube. Pulled vac for 90 minutes, vac held for another 90 minutes. Recharged system with no change in results. Ambient temp was at 97*, Static pressure 120 lbs., low side at 103 lbs., high side at 140 lbs. I'm out of answers, the only thing that I can think of that could possibly be wrong is the compressor is failing. Does anyone know a good brand of compressor? I don't want to do this again in 3 years!

 

What about a bad fan clutch? would that produce these results? I was reading in another post https://www.ford-trucks.com/forums/8...placement.html to test the fan clutch run the ac on max at 1500 rpm for 5 min., then mist the condenser with water, if the high side pressure drops rapidly, the fan clutch is toast. Going to try this after work tomorrow, need the ac, 101 today, 103 tomorrow!

 

i still say your compressor is bad.

 

If a fan clutch was bad you would have a high reading on the high pressure side. It could go down when driving due to ram air or with water on condenser.

High low side would be clogged evap, overcharge, air, OT, or compressor.