Restoring an old A/C System on 94 Taurus

[Gene]

OK, so I am back with my 1994 Ford Taurus GL, 4-dr sedan, 3.0L OHV FI engine (Engine Code U) with another issue.

Thanks to the help here (Thanks again to all who have commented & helped!) and Eric Videos, I have completed the following repairs so far:
[i]Replaced Rear Qtr Panel Window
Repaired Passenger side head light – caved in
Replace Heater Core
Replaced Driver door latch
Driver door – RUST
Driver door window seal
Replace Thermostat
Replace leaking Radiator
Replaced all cooling related hoses
Replace Ignition Key lock
Fixed Front end vibration
Repaired Windshield Washer[/i]

Now the last major item on my “wish list” of repairs for this car is getting the A/C system running again!

The History
Got car ~ 5yrs ago from a relative who was the original owner. It now has ~90,000 miles on it. The AC went out probably 10+ years ago and the owner was told it could cost as much as $1K to repair and decided to run with just “480 Air” ( 4-windows and 80 mph!) Now that I have been getting dirty I like to try to get the AC running again. I’m not sure I’ll know what to do with a car that has both heat and cooling! 😉 But hey, I’d like to try!

While I had the dashboard torn out of the car to replace the Heater Core, I also replaced the Evaporator. I left the seals on the ends of the evaporator as to not introduce any moisture or inadvertent debris, bugs, etc until I decide to repair the AC system. Since the Accumulator/Drier was broken open during that repair, I know that it needs to be replaced. (I assume with some kind of leak and 10 years time, replacing the drier would have been required anyway.) Oh, and while replacing the radiator, I found one of the lines separated on the “cluster” called the AC Manifold and Tube (basic part number 19D734). Looks like the “crimped on” factory clamp at the rubber to metal connection was gone. So I pushed it back together and added a hose clamp.

The Question
So the question is what steps do I need to take to restore this AC System?

Proposed Procedure – please comment on!
I have watched 7 videos on the topic and read Eric’s writings and wonder if the below defined path is the way to go? Must be some missing steps? Might be out of order? Please let me know?

A. Buy & Install a new Accumulator/Drier
B. Run a vacuum check on the system to see if it leaks (holds vacuum)
C-1 Leaks= Yes: Pressure test with dye to find the leak & repair
C-2 Leaks= No –> go to next step
D. Check compressor function, clutch engaging, fan cycling, pressures hold, temperature check in passenger compartment
E. All OK? Yes = REJOICE! No= Ask more questions
F. Use Cal-Clean to clean the Condenser for optimum performance

Ok, yeah, and I get to fight those lovely Ford spring lock couplings again! Guess we’ll see if I learned well from the advice on this forum!

Basically it looks like THIS system has 6 parts to it:

1. Evaporator (already replaced= new)
2. Accumulator/Drier w/ associated hose (will replace with new)
3. Condenser to Evaporator Tube
4. A/C Manifold and Tube (set) aka Refrigerant discharge / Suction hose assembly
5. Compressor with clutch
6. Condenser

Since I can get the three hoses with Drier and condenser for under 150 and a compressor for under 200, I wonder if it doesn’t make sense to replace everything? Or can I get away with minimal repairs?

Also I suspect I need to add PAG oil somewhere in the above noted process- probably at the time I recharge the system with R134.

Also wonder if I need to replace ALL of the seals. I know if this was an R12 to R134 conversion all new seals would be required. But it isn’t, so do I need new seals all around?

What else am I missing? How should I approach this?

Thanks again! Looking forward to the kind help!

Topic

[Andrew Phillips]

[quote=”CanDo807″ post=139978]Still wondering if there are “standard” things that get disconnected when the dealer disables an A/C system – or things I should look for?[/quote]

Never heard of anything getting disconnected really. They usually just recover the refrigerant and call it a day. Once the refrigerant has been removed, the low pressure switch keeps the system from activating. I guess it’s possible someone might pull a fuse or relay, but nothing else should really be done to it besides sucking out the refrigerant.

[Gene]

[quote=”cap269″ post=139979]Never heard of anything getting disconnected really. They usually just recover the refrigerant and call it a day. Once the refrigerant has been removed, the low pressure switch keeps the system from activating. I guess it’s possible someone might pull a fuse or relay, but nothing else should really be done to it besides sucking out the refrigerant.[/quote]

OK, fair enough.

On the Ford the refrigerant probably leaked out, so no need to remove of recover it!

One reason I asked is that when the same situation happened to the 89 Accord, in that case, the technician did “disconnect” things:
removed the belt from the compressor
Disconnected the fan electrical connection (found when I changed the radiator)

Thanks again! I’ll post the next “fun” I’m having…. soon…..

[Andrew Phillips]

[quote=”CanDo807″ post=140137]One reason I asked is that when the same situation happened to the 89 Accord, in that case, the technician did “disconnect” things:
removed the belt from the compressor
Disconnected the fan electrical connection (found when I changed the radiator)[/quote]
I can somewhat see removing the compressor belt, although leaving it on doesn’t hurt anything. There is practically zero load on the engine from it when the compressor is just idling (not engaged). As for the fan, that should not have been disconnected, because the computer can actually turn that fan on if extra cooling is needed to prevent an overheat. And again, no real need to disconnect it, it won’t turn on unless needed.

[Gene]

[quote=”cap269″ post=140140] I can somewhat see removing the compressor belt, although leaving it on doesn’t hurt anything. There is practically zero load on the engine from it when the compressor is just idling (not engaged). As for the fan, that should not have been disconnected, because the computer can actually turn that fan on if extra cooling is needed to prevent an overheat. And again, no real need to disconnect it, it won’t turn on unless needed.[/quote]

Hey, that is a good thought! I’ll have to remake that electrical connection on the Honda! I guess I didn’t know that was a possibility. Were computers THAT sophisticated way back in 1989 (is that b4 OBD1?) that the computer would turn on the dedicated A/C fan for extra engine cooling? In effect running two fans at once? If so, is it possible I have damaged something running it hot for many years?

Now on to where we are…. That manifold to compressor connection is driving me buggy! Was torquing on the bolt and it was taking enough “factory grunt” that I knew it wasn’t right. Still gotta figure out what is the demon in this so I can get this connection seated? Sigh.

Just for fun I connected up the A/C Gage set and the vacuum pump ( OEM brand on both) to see if there was indeed a leak. Yeah, red line to the high side (“H” on the cap – close to Condenser) and Blue line on the low side (connector next to Accumulator/Drier). The second I kicked on the vacuum pump I know something wasn’t right – it just didn’t sound right.

I rechecked everything including proper positioning of the “valves” on the H & L connectors – yeah they were cranked down to depress the associated Schrader values. I disconnected the yellow line (middle line) from the valve set, up next to the valves, and while the pump was running I could not detect any vacuum. Took the other end off the vacuum pump and put my finger over the end of the nipple on the pump and got the same thing I get when I cover the business end of a shop-vac hose. So it seems the vacuum pump was working. [Oh and the oil level in the sight glass was perfectly even with the line markings on the case. Brand new machine, so I’d hope so!]

Then I noticed it looked like there was, what looks like it might be, a check valve on the curved end of the yellow line. Depressed it with a screw driver so know it works and isn’t jammed shut. So I guess this was designed for when one is filling a system and needs to switch bottles, the check valve keeps everything from escaping if one does a Homer Simpson “DOH!!” and leaves the valves open on the gauge set! So if this valve is one way, then why not just switch it end for end? So I did that and still could tell I wasn’t applying any vacuum to the gauges.

Oh and I should say at some point, I finally pulled the manifold off of the compressor and placed the factory sealing “cap” back on the manifold. It goes on very tight! Figured any leak would be at one of my joint connections or at the Condenser.

So what about this line? Does that check valve screw out? How do I used it?

So what I did figure out I could do, is I found a foot long piece of plastic tubing that “just” fit on the brass nipples on the vacuum pump and the gauge set. Snugged it up and fired up the pump and could see the needle on the low side moving negative slightly. Unfortunately that hose was only 1-foot long and I didn’t wanna stand there holding the pump up for 30-minutes. So something to buy, unless I can figure out how to work with the yellow hose that was supplied. Then again, it is REALLY humid here (take a step outside the house and sweat a bucket). So not sure I wanna vacuum the whole system until I’m ready with the refrigerant. After all, I’d have to open the system up again and that would just allow all of this lovely moisture in the air to get in there!

So making some progress – slow as it goes as I struggle along with ignorance and some trepidation.

Appreciate the knowledge, education and confidence I get from the site! THANKS!

Attachments:

• ACRepair055.jpg
• ACRepair058.jpg
• ACRepair053a.jpg

[Andrew Phillips]

You can remove the schrader valve(s) from the yellow service line. It unscrews like a tire valve stem core, because it is the same thing. I took it out of mine years ago.

[Gene]

OK, so I worked my way back from the manifold and removed all of the clamps holding the A/C lines down. That gave me play to move the manifold freely and it seated perfectly on the compressor. Screwed the bolt down and all was good. Now I just gotta figure out what to do with the line spaghetti.

Guy at the hardware store used snap ring pliers to get the end off of the yellow gauge-set line. Then he took it in back and wrenched the valve out of it. Sold me a new o-ring for the one he had to destroy.

Connected up the vacuum pump and finally got negative pressure readings on the gauges! So I let it suck away for 30-minutes while I went back and reviewed the “How to Recharge” video. 5-min to get started, 23-min video and came back and had 24-in of vacuum on the system! Is it possible to have leaks and still draw that kind of vacuum?. Anyway, let the system sit for 25-min while I ate lunch and it held 24-in. So far so good!

Then I realized that I needed the valve that goes on the top of the refrigerant can, so I restarted the pump and let it run while I ran down to the store for a valve. Came back and hooked my 14-oz can of R-134a with leak detection on to the yellow line. Oh, btw, the leak detection stuff works as the nipple was leaking a bit. So had to tighten things down to get the o-ring seated and all was good.

Started up the car, put the thermo inside the center vent (it read 100-F), set the A/C on Max A/C, temp dial to max blue, fan on low. Went around and opened the blue valve on the gauge set and the gage needle jumped up. Turned my can of R-134a with dye upside down and the blue gage was up around 80. After a bit it dropped and then viola! the high side gauge jumped up! Whoo HOOO! Looks like the compressor was working! I’m thinking – cool air here we come!

But alas! My excitement was rudely interrupted by a large POOF!

My old nemesis a “quick connect” fitting blew apart! The lower fitting on the condenser – the one that attaches to the liquid line! Huh? I’m pretty sure I had it seated when I changed the lines. So I pushed it back together very firmly and heard the connection “click.” Also, then checked the other fitting that was next to it and it appeared to be seated.

So no problem, I have a second can, since the system takes 2# to charge. But in stepping back, I can’t figure out why that lower connection – the one I know isn’t seated (see above pics) – hasn’t blown apart? Anyway, repeated the procedure with the second can and once again thought I had success when the upper quick connect on the condenser blew apart! Did I ever mention how much I LUV quick connect fittings???

So if you notice a slightly bigger hole in the ozone layer today, well that is me and the lovely quick connects. My bad fellow citizens! My bad! Oh, and there has to be a better way to paint one’s engine compartment green than the procedures I just used! {nah – not gunna post a picture of THAt mess….}

Now before I go out and buy some more R-134a to discharge to the atmosphere in unique and unusual ways……

What should I do next?

[Gene]

Thanks again for all of the help here! Finally had success! Got the quick connects together and seated and put those black clips on and all was good.

Ran a vacuum test again and got 30 inches of vacuum after 10 minutes! Shut down vacuum pump and it held for 15-minutes! Charged up system with 3 – 12 ounce cans of R134a refrigerant. Stated capacity is 2 pounds.

When I was done I let the system run and cycle for a while and then recorded the below figures from the gauges. Ambient air temperature was about 85-degress F and high humidity.

Low @ 42-45 psi…………High @ ~100 psi
Low @ 24 psi………………High @ 170 psi

Shut the car off and the gauges stabilized at 52 psi on both High and low side. Attached is a copy from the service manual of the pressure temperature relationships.

Have been driving car around and the cool comes out nicely.

So am I good to go? Everything look “OK” or normal?

I have videos of the gauges that I could post if that is needed?

Attachments:

• FordACSpecs2.jpg

[EricTheCarGuy]

Well, I did mention there might be ‘issues’. Glad you got it sorted. Thanks for the updates and for using the ETCG forum.

[Gene]

Well I could not have done it without you and the kind people here!

Thank you!

[Bluesnut]

My suggestion is to replace every 20 year old seal you can locate and the compressor which also has 20 year old seals in it.
Even if the old compressor doesn’t leak odds are it will once back in operation.

Use a vacuum pump to pull a good vacuum and leave the pump on for several hours. This will assure the removal of any and all moisture in the air. Moisture contributes to refrigerant oil contamination and acids forming.

I’ve converted a few of these cars to R 134 including one I owned and the A/C was outstanding afterwards. On a trip here in the very hot Southwest on a 100+ degree day that unit would put out 30 degree, or even less, air and after 50 miles or so I’d end up turning the fan speed down because everyone was freezing. And that was on a station wagon; not a sedan.

[Author]

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