Hello friends,

Dog days of summer are coming and I have a van with no A/C! I just bought the rig recently and the previous owner said the A/C blew cold front and rear the day before I bought it (go figure). Before I did anything, I took notice of the fact that the A/C clutch was ALWAYS engaged as long as I had the A/C selected on the dash. It never stopped and it never cycled. While the A/C was not selected, it stopped. Also, when the vehicle was off, I could spin the clutch fairly freely. I don't think the clutch is the problem. Anyway, I put a manifold gauge set on it with A/C on and saw that both high and low sides read about 35 psi. Their was no cycling and the two stayed exactly the same psi. I have consistently read that 35 psi should be a good charge, but i thought I might try to put a little more in and see what happened. I grabbed some A/C pro from Advance Auto and started filling. I ended up putting in an additional 20 psi (probably way too much) and I did at least start to feel some cooler (not cold) air coming through the vents. However, the low and high pressures remained exactly the same as eachother at 55 psi.

I have searched and can't find anything out there that addresses this scenario (high and low pressures staying the same). I am far from an a/c technician, but my list of strongest possibilities so far is:
- compressor completely shot - not making any pressure at all
- restricting orifice destroyed or missing, not allowing pressure build up

Is it worth taking it in to simply have the system evacuated and re-charged? I am reluctant to do this simply because it will probably run me $200-300 given the size of the system and I would hate to waste that kind of money. Any ideas on what might be going on here? Any electricals i should try testing? Like I said, the unit seems to be responding appropriately to the selector switch.

By the way, the van is a 98 E350 7.3 PSD w/ Quigley conversion. I need to get that added to my signature!

Thanks
Eric

 

I am a HVAC tech. Your compressor is shot! The low side and the high side should NEVER be the same psi when the compressor is engaged. The low side should be around 35-45psi (roughly, depending on the outside temperature) and the high side should be around 150-200psi. The engine rpm and outside temp have quite a lot to do with the pressures. In any case, your compressor is definitely shot!

 

pbarsoum,

Wow! Thanks for the quick response! Now for the repair question....

I assume there is a fair chance of debris in the system from the compressor failed internals? What do you recommend I do to clean the system? Or should I just replace other components as well? I see these full A/C system (compressor/evaporator/etc) replacements on eBay for pretty cheap, but I am usually an OEM guy, which sounds like an expensive proposition if I have to replace more than just the compressor, which isn't too bad of a job on these units.

Thanks again!

 

correction - the system replacements include the condenser, not the evaporator. See kit via link below....

New A/C Kit for E350 - eBay

 

I'm an OEM guy as well. I would stick with OEM new (not re manufactured!). Definitely replaced the receiver/ filter drier, also there is a metering "orfice" with a screen attached to it (very easily accessible on the liquid line by loosening the nuts to get to it), you can just clean it with a solvent like carb or brake cleaner. It gets a bit involved but you also must put the system under vacuum once the system is repaired to properly charge it. Once you get everything in place, you might just want to take it to a shop to have them evacuate and recharge the system with the indicated amount of charge of refrigerant.

 

thank you pbarsoum! So i think what you are saying is that i shouldn't need to replace my condenser and that the dryer and/or orifice screen should have caught any debris from the compressor?

 

I would stay away from that "kit". That is a "fits all" kit. You don't need the condenser or the expansion valve. The small pencil looking thing is that orfice and screen I was referring to. The cylinder or canister is the receiver/drier I was referring to also.

 

The receiver/driers are relatively inexpensive also.

 

fantastic. I will get the order placed. I think you are right - best to have the shop charge up the system....

 

Yes, you're on the right track!

 

My "03" E-350 Super Duty holds around 3lbs of R-134 but if you have a Club Wagon with rear air, it's obviously going to hold more.

 

Let me second the idea of using new OEM parts---once you have the Motorcraft part numbers finding what you need or want can result in a considerable cost savings. I have an extended body E350 Club Wagon that came to me with the rear A/C which I immediately disabled and removed most of those parts. I had to replace the receiver/dryer, the high side hose and changed the FOT just for grins as well as the Schraeder valve core stems and caps. We won't talk about an "lost" Snap On 3/4" combination wrench that took out my original condenser---that one still hurts.

A/C System capacities are (or should be) clearly displayed under the hood on the plastic trim panel covering the radiator & condenser mounting areas like this:

 

JWA, those 3/4" Snap On Combination wrenches are really expensive!

 

Boy howdy that's for dayum sure!

I got off kinda cheap though---the replacement wrench was a mere $55 but it'll last a life time of my limited use; have a friend in the new aftermarket radiator business so he hooked me up with a condenser for $95 out the door. Evacuating and recharging the system was basically free but the customer's shop who did that work just asked me to give them a discount of some sort next job we did---I deducted $60 and bought the shop lunch.

And yes I did use an aftermarket part ONLY because I wasn't sure the condenser had a leak, didn't want to replace it without a good reason, had guessed and feared there was another leak in the system or a failed compressor. During removal though I found this:



Come next summer and fingers crossed there are no issues with the A/C this summer I'll probably replace the Chinese condenser with an OEM part as I notice a tiny bit of reduced efficiency with the current part. That'll be about $300 from dealer or through eBay private seller.

Good times!

 

Wow! That's quite a hit!
Sounds like you made out in the long run though!
If you know an HVAC guy/gal that does commercial refrigeration (like myself), take the R134 out and have him/her put R-409A in. It works far better performance wise than the 134 does! I run it in all of my vehicles!