Well, it's hard to find the condenser by the YJ351 designation. And using the E69Z-19712 number turns up both early and late models, so it's a little confusing. I'm guessing that 1996 is when Ford switched to R134A, and maybe those model years are the ones to get for their greater capacity. But it's hard to tell with the way most e-tailers advertise.

I ordered the Spectra Premium model from Rockauto.com. I hope it works as well as the Motorcraft.

Incidentally, this turned up on a search for YJ351:

http://www.epa.gov/Ozone/title6/609/oneshop.html

This is a write-up on R12 to R134a conversions posted on an EPA website done by an AC shop in Florida. They wrote in generalities for the most part, but they actually called out the upgrade to a YJ351 on an Aerostar.

 

the YJ370 is for the 96>97 Aeros

many of the non OEM aftermarket manufs make what they call universal or multi app. units aka kindafit.
the Chinese are great for this, god only knows where they get their specs, out of thin air?

 

Got the Spectra Premium condenser a couple days ago, installed yesterday, and assembled system today. The new core looks just like the old core, with a small difference; the connectors have THREE O-rings and grooves, instead of the stock version with just 2. The mating ends on the original hoses seem to slip over just fine. It looks like someone acknowledges that this is a problem area, one of which was leaking on my old one. This one was made in Mexico; I hope it will last.

I have a small problem with the new accumulator from Rock Auto. Its shape is just a little different from stock, so with it connected to the outlet of the front evaporator, it is tilted a little bit. This prevents the mounting bracket from reaching the air box where it's screwed to. To give it support, I had to remove a screw from each end of the bracket so it can reach one of the holes in the box.

I put about 5 ounces of oil in the compressor and turned it to help distribute it. It spat out about 2 ounces. So I loaded the balance of oil into the accumulator.

After assembly, I started to pump the system down. It was pretty humid last night and this morning, so there must be a lot of moisture in the newly flushed lines. For the first half hour or so, the pump was putting out quite a bit of vapors. So I let it run for about an hour before shutting it off. When I did, the internal pressure started to creep up. I hope it's because the fluids inside are still evaporating, and not because of a leak. I'll try again tomorrow.

 

This is hopefully my final report on my AC repair.

After doing all the replacements of parts and seals, I flushed, assembled, and evacuated the system a couple of weeks ago. Then pressure tested with about 90 psi of dry gas I had around (argon from my welder). It held for a day, so I evacuated it again, getting ready to fill with refrigerant. But at first, it would not hold vacuum. Through trial and error, I found that it would leak from the fittings from the hoses on my gauge set. I thought maybe I just didn't tighten them properly, so after a bit of fiddling, I finally got it to hold vacuum for a day. So I fill it with refrigerant, and all seemed well; it made nice cold air in the low 60s while idle, dropping down into the 50s running on the freeway.

But a few days later, I go into the garage and smell the tracer odor added to the refrigerant. Something's leaking again. Sure enough, the AC cycles way too often, and the pressures are down again. I check all the fittings to look for oily leaks, but found none. I found the strongest odor under the hood. While poking around the accumulator, I hear some sputtering noises. I followed that to...one of the Schrader valves on the new accumulator. It's leaking slowly, spitting out a little oil sometimes. I then find that all the valves sputtering a little. I first made sure the valve cores are tight; they are, but still sputtering. I find that if I wiggled the stem a little, they will stop. The seal just seems too tenuous. I didn't want to replace them, which meant releasing what's left of the refrigerant, and having to re-evacuate the system. Besides, one of them was new, and it was leaking.

So I wrapped a few layers of teflon tape around the outside threads of each valve body before screwing the caps on. Checking a day later, one of them made a "pop" noise when I pulled it off, indicating the valve was still leaking. But at least the teflon tape was working. So I tried wiggling the stem again, and re-taped the body, and capped it. I've re-charged the system to bring it up to normal pressures, and it seemed to have maintained for a few days so far. I'll have to keep an eye on it, and probably change out the valves the next time the system leaks down to nothing. It's always something...

 

Feel for you man. It is certainly discouraging to get so close and have this happen. Caps/teflon won't hold up to these pressures for long, so you may as well bite the bullet and replace. Sure is odd all the valves would leak. Unless you can get good quality replacements, it may make more sense to replace the entire accumulator. Good news is, you seem to have the system dialed in for optimum performance - or as good as it gets in these vans. Hi fives on the effort!

 

sorry to hear about the accum. headaches. what brand? maybe save the rest of us some headaches when we replace the next time. bad valve core seals.

R12?

might try a new cap with O ring seal
may help to put a couple drops of comp. oil in the valve before putting on the cap to lube the valve rubber, may have dried out.

https://www.ackits.com/pc/35-16361S/...ersion+Fitting

http://www.ackits.com/merchant.mvc?S...ory_Code=Nylog
NYLOG renders a strong, flexible, lubricant glaze that prevents high pressure leakage through refrigeration gaskets and threaded fittings. NYLOG never hardens and always
remains temperature and vibration resilient. NYLOG is fully miscible with all refrigeration fluids and can be used for high tack lubrication on internal compressor parts, system valves, seals and much more.

""""
If there is an o-ring in the plastic cap- the cap will seal any leaking schrader valve-- I know this goes against general thinking- but the schrader valve is there just so that you can remove a gage set and install the cap-- The cap IS the primary seal the schrader valve is the secondary seal. I know this because I have talked to the designers of these systems- this is why there is an o-ring in it -and it always baffles me the number of vehicles I see with no caps on them.. Also I have done numerous testing where I had to use a valve port- with no schrader valve and only a cap- the cap will seal-- although for safety reasons I would never do this on the high side-- So based on this- if your cap was on tight and it had an o-ring in it- I would look elsewhere for the leak-- a '91 Park Ave is a primew canidate for an evaporator leak/plug up-- I would look there first........

 

This was an accumulator I got from a close-out at RockAuto. It is a bare aluminum cylinder with squared ends, unlike the original steel painted black with rounded ends. It has the 2 Schrader valves like the original; one for the pressure switch, the other is capped. I used the one for the pressure switch to evacuate the system, as it seemed to be the most effective port to be pumping down. I happened to use the other to monitor system vacuum/pressure at some point.

The caps do indeed have O-rings in them. I did not realize that was the primary mode of sealing them, so I did not put them on tightly the first time. So the other 2 Schrader valves were on the lines going to and from the compressor, and the one on the high side was definitely leaking a bit until I put the tight seal around it with teflon tape. But it sounds like the O-ring should hold. So now I have both, and I think I'll leave them until there is a problem again (hopefully not).

thanks for the info, 96.