Also, I am not sure if you can get all of the oil out of the filter dryer, you may need to replace it...Mark

 

Alrighty, thanks so much mark. I am able to get ahold of r-12, so i'll totally evacuate the system and re post with results. Also do i have to remove the compressor again? Why wouodnt the oil level affect it during early morning and late evening hours?

 

I don't know, could be that the temp has something to do with it. The best thing would be to take out the compressor, empty it out, put in 8 ozs of oil and re-install. I really don't know if the filter dryer can be saved, hopefully a more learned member will chime in. If it were me, I would just replace the filter dryer, they are not too expensive, good luck...Mark

 

Also, don't just evacuate the system, flush it out so that you can get as much of the oil out as you can. Flush kits are available for rent from most ac shops. Then, of course, evacuate and recharge. You may want to consider replacing the high pressure relief valve on the hose manifold. It can hold a vacuum, then leak under pressure. It also has an O-ring. Check my ac thread that I linked to early in this thread, all of the mentioned part's numbers are listed in there...Mark

 

Sorry, this is the thread I was talking about...Mark

 

It's cooling, but either the evaporator is not totally wet, or it's being overwhelmed with intake heat.

Evap not totally wet..... insufficient freon, If high side pressure is adequate, about the only thing that would do that is the expansion valve.
Expansion valve. Check the temperature of the tube exiting the evaporator and going to the compressor. It should be pretty cold, as in 40° or so. If it's closer to the temp of the exit air, this may be the problem.
A. plugged
1. a drop of moisture freezing in it
2. excess oil plugging it up
B. wrong expansion valve, small orifice
C. Improperly installed, sensor located so it cools off too soon.

Overwhelmed
A. If the above mentioned hood seal is bad, you could be pulling in 250° makeup air instead of 95°.
B. Seal on the bypass door
C. Heater coil hot because water valve fails.

hope it helps

 

Did you see that he had completely filled the compressor with oil?...Mark

 

If the system gets opened, you should replace the drier. There is a way to flush the compressor, and it doe need to be removed from the truck. You use a power drill to spin the compressor, and you use what ever oil you will use in the system to flush it. You flush from the suction side and let it drain from the discharge site. Mineral or Ester oil is recommended.

You also have to remove the expansion valve. I did use pure methanol to flush the lines, evap, and condensor on my MB. I used a borrowed flush gun and air compressor.

 

Of course. Did you notice that he never responded to the query about the hood seal?

I just thought I'd fill in the matrix, sort of a check list. I don't think he's sorted out whether the evap is too dry, or overwhelmed.

 

That's fine, but you would agree that the system is probably severely over full with oil if he filled the compressor with oil, then added a 2 oz oil charge, right? IMHO that is a probable cause of his symptoms...Mark

 

I think if the compressor had been actually "topped off" with oil that it would have been locked as soon as it was started but overcharged with oil would defiantly affect the ability to cool.

Most of the times I had complaints of not cooling in the heat of the day but cools fine in the evening and it has not been simply low on charge, it was because it was not evacuated long enough and there was still some moisture in the system, a drop of moisture would freeze in the expansion valve.

Here are the specs for the oil charge for the C171 Chrysler compressor this is what you have if your truck is non intercooled.

http://www.rtitech.com/downloads/New...Compressor.pdf

The only sure way to know how much oil is in the system is to discharge and dismantle the system, remove and drain all of the oil out of the compressor, flush out all of the components including the evaporator, condenser, expansion valve, and all of the lines,

You want to replace the drier, all of the o-rings, embossed gaskets and the relief valve on the discharge port.

Auto Zone sells a decent aerosol flush or the solvent alone if you have your own pressure gun.

Refill the system with the appropriate amount of oil according to the components from the list above, there is no mystery about how much oil there is.

I would also add about a 1/2 ounce of UV dye to the system before it is recharged making it easier to find a leak in the future.

Jim

 

Well sure. Would you agree that it's worth 3 minutes to verify that the evap is not chilling and being overwhelmed or bypassed before the system is evacuated and dismantled.

 

Good morning to everyone and thank yall so much for everyone's input. I havnt had a chance to check all the stuff yall have told to me to check for cuz of work but i am going to do so this afternoon, i'll keep yall posted as to what i find b4 i evacuate everything.

 

That would be good info, but the system needs to be disassemble regardless of what else is found. Unfortunately, IMHO, he is at square one regardless of what has been done, it's like a completely new problem...Mark

 

Hey buddys, on the same note, i forgot to say that b4 i replaced all the components of the ac system the truck was doing the same thing. It would only cool in the mornings and evenings and not during the hot day. The reason i replaced the compressor was because the gauges were inconsistent, bouncing up and down as it had bad compression. That is the reason i replaced it along with everything else, but it did do the same thing b4 the parts being replaced.