99 Taurus A/C uncool

Hi...
I have a 99 Taurus 3.0 Duratec, AX4N, Climate Control, owned from new.
Never any problem with A/C cooling, tho a few electrical problems.
Regularly driven til last year, now about once a week.
Not cooling when A/C first used this year. Compressor short-cycling...so I assume there was 'some' pressure in the system. I should have checked static pressure first.
Hooked up the gauges and added a little 134 (30 lb tank with over 3/4 left) . Compressor cycles got longer and air got cooler. The high side gauge fitting started leaking, so I aborted the mission. Probably leaked it right back out. Now back to square 1...no cold air.
So...once I get the gauge fixed, any suggestions as to what pressures I should see at, say 80F?
I know basic A/C theory, and have had moderate success working on my own cars before...or...I know enough to be dangerous :)
I know the 'right' way is to have it evac'd, tested, recharged with x.xx lbs of 134, tested again, etc. I'll do that if I have to; but I'd like to get a handle on it first.
Thanks, Don
Don Byrer KJ5KB Radar Tech & Smilin' Commercial Pilot Guy Glider & CFI wannabe kj5kb-at-hotmail.com
"I have slipped the surly bonds of earth; now if I can just land without bending the gear..." "Watch out for those doves...<smack-smack-smack-smack...>"
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Well...ME, mister "go freakin look it up on Alldata" (or factory book, Helm, etc...) did just that...I found complete charts of pressures AND compressor cycling times vs temperature on Alldata.
Any other suggestions would be appreciated; especially on charging procedures for a partially charged system.
Thanks! Don
Don Byrer KJ5KB Radar Tech & Smilin' Commercial Pilot Guy Glider & CFI wannabe kj5kb-at-hotmail.com
"I have slipped the surly bonds of earth; now if I can just land without bending the gear..." "Watch out for those doves...<smack-smack-smack-smack...>"
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I had the same problem with my 1978 Ford Granada. The a/c just would not blow cold. I hooked up the manifold gauge set and everything appeared to be ok and there was R-12 in the system. The problem turned out to be a sticking expansion valve. The expansion valve is a rectangular block with an adjustment button on the bottom. A friend sat in the car and watched a temperature gauge while I opened the button. As soon as the gauge read 30 degrees I stopped backing out the button.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Don Byrer wrote:

It's really not a great idea to "top off" a partially charged system. Due to the reduced size of modern systems, the "window" of acceptable charge is only a few ounces. It's a bit like topping off the oil in your engine without a dip stick. You should at least recover the remaining refrigerant, evacuate the system and charge by weight. This will also remove any moisture in the system (and give you a chance to fix the leak so you don't have to recharge again alter). All of those charts and tables look good, but you'll find them cumbersome to use in the real world.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Don Byrer wrote:

A good rule of thumb on the pressures: 28-32psi on the low side, 2.5 times the ambient temp on the high side (Max AC, High Blower, 1500 RPM, doors open). Evaporator inlet and outlet pipes the same temp, and the suction line cool back to the compressor. The system will have UV dye in it from the factory. You should be able to find the leak with a black light. Any of the spring-lock fittings are suspect. Compressor shaft and body seals, and the suction line running in front of the motor are next in line. If the power steering leaks near the pump, the oil can damage the lines on the compressor manifold.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Thanks...That's pretty much what the charts give me.

Wasn't sure if they did that. Will have to drag out a blacklight and inspect.
Might be a week 'r' so til I get back to it. Will check it out & post my findings.
--Don Don Byrer KJ5KB Radar Tech & Smilin' Commercial Pilot Guy Glider & CFI wannabe kj5kb-at-hotmail.com
"I have slipped the surly bonds of earth; now if I can just land without bending the gear..." "Watch out for those doves...<smack-smack-smack-smack...>"
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Update:
Got a new o-ring for my hi-side gauge, but wasn't confident it would hold. Hooked up the lo-side gauge only.
Static pressure-engine off ~10 PSI. Obviously a leak :(
Added R134 to ~ 70 PSI. Figured that was a good start (yes, I know I shoulda got a scale out...I will next time). Started engine, lo side short cycling between ~ 25-42 PSI.
Engine off, hooked up hi-side hose, leaking, disconnected it .
ARRGH! darn thing worked fine when new 3 years ago....
Started engine, A/C on max, RPM ~1500. slowly charged 134 til compressor just stopped cycling. Per Ford Data, compressor will not cycle above ~81F, @ 1500 RPM...and my temp was conveniently 80 F today :)
So...I should be 'close' on the charge. Center outlet temp 40F, right in the middle of the chart.
So...I am now an informed customer. I have a leak, and it appears the system is working OK when fully charged.
I have a friend working on the loan of a UV lamp so we can try to find leaks.
I will probably end up taking this to a local shop anyway for the final repair & recharge...but it's nice to know what the problem is. I'm just hoping it's not the compressor shaft seal :(
--Don Don Byrer KJ5KB Radar Tech & Smilin' Commercial Pilot Guy Glider & CFI wannabe kj5kb-at-hotmail.com
"I have slipped the surly bonds of earth; now if I can just land without bending the gear..." "Watch out for those doves...<smack-smack-smack-smack...>"
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Don Byrer wrote:

Yup.

A scale is nice, but you were quite close enough for a test. That's why I like the 12oz cans if I'm away from the charging station. Most systems hold close to a multiple of 12.

Crap!! I missed where you said it was leaking. If it's at a hose connection, I've found that I'm always better off chucking the hoses and replacing them every couple of yrars, rather than trying to reseal the old ones. Resealing them "should" work, darn it...

That's pretty good. You've got some air in the system from the leak. Once that is gone, you'll probably see ~35-38.

I hope it's not the seal also. Look close at the larger line (suction) where it passes in front of the motor. They tend to corrode under the foam insulation, as does the accumulator if it is wrapped in foam.
Best of lick.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Don Byrer wrote:

You've got three problems:
1) You don't have enough coolant in the system.
2) There is a leak in the system.
3) You don't have a clue what you're doing or the proper equipment.
You can solve these problems by bringing the car to someone who has equipment and experience, like your dealer.
Playing with this yourself is dangerous and stupid.
Jeff
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Jeff wrote:

Likely more than that, but the problem he was asking about was with the AC on his car.

No, he doesn't have enough Refrigerant. There's a big difference in the two.

He knows that and acknowledges it.

No he didn't, but he is taking a pretty darn good approach at learning, and is doing pretty well.

Yes he can. But AC repair is not rocket science. It can be done DIY, especially the way is going about it. He is really taking the long way around just to take it to a shop, though.

Very much so, but he seems to understand this. He actually seems to have more than half of a brain. If he blows his fingers off, it's on him. It doesn't seem likely, though, the way he is proceeding. I haven't seen you add a precaution to this thread until this point. Where have you been until now with your concern for his safety?? The original post was 9 days ago.

Yes, that's your name. Now grow up and be a productive member of society instead of trolling usenet.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Tom Adkins wrote:

Actually, it is.

Have you ever taught kids in NYC schools? Taken care of sick kids in a pediatric ICU? Or there brothers in a camp for kids with cancer? Mentored children in NYC or coached them in soccer?
I have.
IMHO, I think what this guy is doing is dangerous, without the proper equipment and training. I expressed my opinion.
If you don't like it, in the words of the NYC kids: Tough doo-doo.
Jeff
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

So you are the guy responsible for training all the kids in NYC schools eh? You are such a multi talented guy, you forget about being an automotive expert. I guess being humble is just your personality.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Follow-up:
UV lamp showed numerous pinpoints of yellow, as well as a ~1" streak near the base of the condensor coil, near the hose connection.
I washed the engine compartment thoroughly, then added a partial charge just the get some pressure back in the system (and maybe force more dye out.)
Took it to local shop today...condensor has a hairline crack in it...arrgh. $800 to replace condensor (which I don't wanna do myself), accumulator (probly needs it) and recharge.
Not bad considering I don't wanna do that one myself...and it's a reputable shop. AND I'll have it back by the end of the day :)
--Don Don Byrer KJ5KB Radar Tech & Smilin' Commercial Pilot Guy Glider & CFI wannabe kj5kb-at-hotmail.com
"I have slipped the surly bonds of earth; now if I can just land without bending the gear..." "Watch out for those doves...<smack-smack-smack-smack...>"
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.