Automotive Air Conditioning Information Forum

Hello all,

I have searched the internet til fingers gone numb. Hopeful for some advice.

I have a 1992 Ford E350 7.5L Econoline motorhome - classic! Years ago I converted from R12 to R134a and have had nothing but grief since. It has the E6DH compressor, which I have replaced several times. I have one that I have disassembled just to learn how it works. I have changed out all hoses with reduced barrier type, flushed with quarts each time, replaced every component - compressor, condenser, evaporator, accumulator and switch, O-rings and orifice tube. Tired of going through accumulators every time it hiccups. I am using double end-capped Pag 46 oil. Have all the tools, and years of experience. The RV has only one evaporator for cooling. I have experimented with other refrigerants.

I have considered replacing the E6DH with another compressor for which I can find parts. I cannot find any repair parts for the E6DH other than a clutch - no O-rings, gaskets, etc.

I have found that the FS-6 may be a candidate, and seems to be preferred. I would have to replace the hose in/out connectors, but it appears that it should fit the same mount, and 6-groove pulley alignment should be the same. However, I have not acquired one to test fitment. Your assistance highly appreciated.

Thank you
RJ

E6DH compressors are available.

What sort of problem are you having?

If you have had multiple compressor failures, a chronology of events will help us to diagnose it.

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Hi,

Thanks for response. I cannot find internal parts for the E6DH. I own three right now. I would like to be able to disassemble them and repair if possible. But no parts are available. Also, they are quite expensive. I would rather replace with an FS6, but don't know if this is possible. It is half the price, has a good reputation, and I can purchase internal O-rings and gaskets, etc. Your opinion please.

The problems were caused by repairs not done correctly. I had a shop convert from R12, and it lasted a year. They did not properly flush it. I decided to do it myself. The second one failed for unknown reasons - it would not pump, and rattled I disassembled the second one, cleaned it, and now it pumps. But I had ordered a third. It came in new with a bad clutch. Now I am on the fourth by warranty replacement. Too much money for a compressor that I am not impressed with. It appears to be well engineered, but not very dependable. It seems to me that the Chinese quality assurance is not very good.

RJ

If you are flushing with anything other than refrigerant- then that is most likely your problem. Aftermarket flushing agents are degreasers- and you have to get all the flushing agent out of your system! Merely purging with air, or extended vacuums foes not do this. Your evap and condensers have multiple paths and flushing agent can hide in parallel tubes. I used to do warranty analysis for Delphi Thermal compressors- if they smelled like turpentine, then the flushing agent was to be blamed for the repeat failure. This is why GM has the policy to only flush with refrigerant. If you leave some in, no big deal....Aftermarket has convinced the local mom and pop shops to flush with most anything-- it sells product... but can be your worst nightmare- destroying new pumps!

The site sponsor shows an FS6 for that vehicle

http://www.ackits.com/comp-fs6-pv6-500in-3165

The number one cause of serial dead pumps is remaining flush solvent - just like GM Tech said.

That van has a Piccolo condenser. They do not flush well at all. If you have killed a compressor since replacing it, you may need to again.

What does the orifice tube screen look like?

Ordering the lowest priced pump from an online auction or bookstore can be a bag of snakes.

Hi Bohica2

I must have overlooked your previous reference to http://www.ackits.com/comp-fs6-pv6-500in-3165 for a FS6 compressor that (may, should?) fit the 1992 Ford 7.5L engine mount and fitment. It looks identical to my E6DH. However, it is listed only for the smaller engines 4.9L engines. Can you tell me what the specs PV6 5.00 inch mean? And unless it requires a different spin ratio, why would it not function properly, unless the piston cubic inch displacement is much smaller.

And another unassociated question, how much refrigerant/oil does an accumulator typically build up? I have used one that will not drain any oil although I put three ounces in it, and the compressor expelled another two inches. I have one that I may disassemble to check out the innards.

Thanks for this source. Perhaps the above site you provide can further inform me.

GREAT SITE! Thanks.
RJ

That is the listed part for the 7.5L I n that model year.

The phone number for the vendor is in the top right hand corner of that page - give him a call, he is a great guy to work with.

PV6 is a 6 groove poly-vee pulley. 5.00 is the diameter.

The accumulator oil level varies. It depends on the conditions at shutdown.

With all of the failures you have had I would replace the condenser.

Are there any hoses with mufflers in your system?

Hi Bohica2xo

Thank you again. Great service.

No mufflers or filters in any hoses. I removed the one between compressor and condenser when it was converted from R12.

I replaced the previous accumulator when the first attempt at loading the system failed, and I found the system apparently overloaded with oil due to the thickness of the effluent when I flushed the evaporator. This condenser is the second brand new one, installed with new compressor that ran only a few minutes before clutch failed.

I added 3 oz. to that accumulator and 5 oz. to that compressor according to instructions that came with the compressor. But since it was involved in only that short run, I am wondering how much of the 5 oz. I put in that compressor might have ended up in the accumulator.

I have also had another problem with this particular install that I haven't mentioned. I could never get it to take more than one small can of Freon, and the high side gauge would not register pressure building, low side would not accept any more Freon. My brother in law is a professional mechanic and has repaired many AC systems, and I have had an ongoing conversation with him. Nothing worked. So he recommended that maybe my "Harbor Freight" gauge set high side coupler was not working. I purchased new thumb valves for this attempt.

MY plan was to disassemble the system again and flush the evaporator and condenser to assure there was not too much oil in it, but leaving sufficient quantity in the accumulator to make up any shortage, then add 5 oz. to guard the compressor, and attempt to load the system again and watch to see if it will accept Freon. System oil charge is 10 ounces total.

HIS solution was to go ahead and add 2-3 oz. oil to this new compressor, vacuum it down on the low side, then turn off the vacuum and see if the gauges show it equalizing on the high side after a while. If so, I will then open the system again, and then vacuum it down on the high side and repeat the test to see if it equalizes. That should indicate if there is any blockage. Then I would go ahead and start the engine and proceed with install.

Previously, I have vacuumed it down using both the high and low sides for a quicker evacuation. I could perform his suggestion without adding any oil to the compressor or starting engine, and if not blocked, open compressor intake and then add oil (how much?), spin by hand 10 times, and then close system and start engine to see if all this fussing around would work. I always tip compressor to oil clutch, and spin by hand several times to assure compressor oil is distributed, then spin 10 times after installing.

I always leave the high side control valves closed when adding Freon to low side, and know how the gauges work to display information.

Your comment please.

RJ

one thing stuck out of your plans. You were going to vacuum the system to see if it holds and then open it. Do not open a system while under a vacuum as it will draw moisture into the system. Instead, put some refrigerant or better yet, N2 if you have it then open the system.

Let's start with the flushing - What solvent are you flushing with? How are you removing it?

Next the oiling - it sounds like you had too much oil once, and are overcomplicating the oil charge.

The only way to be sure of the oil charge is to clean the system to bare metal & drain the new compressor. THEN add the 10 ounces - as much as the compressor will take, and the balance in the accumulator inlet.

Evacuation should be done with both service valves open. You can NOT evacuate only the low or high side of an assembled system - it is a loop. Once you have installed the oil charge & closed up the system, evacuate to a rough vacuum of 25 to 28 inches Hg, then close the valves & shut off the pump. Wait for the oil to de-gas for at least 15 minutes. Then evacuate to 29+ inches for 5 minutes. Close the valves & check for leaks. If the vacuum holds it can be charged.

You mentioned Harbor Fright. They sell an ok electric vacuum pump. The air powered unit does not create sufficient vacuum for refrigeration use and is a waste of money.

When it comes to charging, do NOT jumper the cycling switch. With the engine stopped, charge liquid through the high side. Hook up the first can as liquid & open the high side valve - it should take the whole can easily. CLOSE THE HIGH SIDE VALVE. Then start the engine & charge the remaining cans through the low side as always. The first can will be enough for the system to "short cycle" . This is ok, the cycles will get longer as you add refrigerant.

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