A/C pro opinions

[Hvyleaf]

Hey everyone, I was just wondering what your opinions are in using A/C pro.
My 95 mtx blew cold for a while, starting dying off, got it recharged and blew ice cold for a month-month and a half. It's no longer working, same symptoms as before, clutch would try to engage, then not.
I'm assuming there is a small leak somewhere, and had someone suggest trying the A/C pro.
I'm using this for a daily at the moment, while my main car is in the shop , so I don't really have time to drop it off for a professional diagnosis.

Thanks in advance

 

[rubydist]

I would put some dye in the system and see if I could identify where it is leaking.

 

[luigisho]

I would put some dye in the system and see if I could identify where it is leaking.

Agree. I've had little luck with that stuff except it adds refrigerant. The sealing? Not that great. For me. Sample size of 1 ..maybe different for others.
The catch 22 with these cars is, any repair that turns into large $ can easily not look like such a great financial idea.

 

[BaySHO Performance]

For the AC to only last a month or so after a full recharge, there's obviously a leak somewhere. If the system has dye in it, an ultra violet light will make it glow green. You might also observe gunk around the quick connects. No point in topping it up until that's fixed.

I've not had much luck with AC/Pro, although the gauge that comes with it is very useful. System pressure is usually 80-100 psi engine off. Cycles between 25 and 47 psi engine on. AC/Pro is unable to get the required pressure into the system in my experience. It also does nothing for getting air and moisture out of the system.

 

[Deathacus]

Agreed. Just get a can of the cheap stuff, half price and no questionable additives, and maybe borrow a gauge and hose. Get her fixed for real once your other ride is back.

 

[Hvyleaf]

Thanks everyone. I tried a small can of plain refrigerant today and as I was adding the clutch tried to engage for longer and longer, eventually the can ran out, is blowing cooler, but definitely still warm. Maybe I’ll try another.

 

[Bluezone]

If you don't have a proper refill unit the best way to judge, is by static pressure. To do this the car needs to sit overnight and acclimatize to Environmental temperature. Make sure the windows are open. So first thing in the morning take an accurate thermometer. Then check the exact temperature. Now connect your refill can with the pressure gauge attached to the low pressure valve. Check with the pressure, without the system having not run. Then compare the temperature and pressure to the available charts for freon type. I've attached one for R134.

Make sure the gauge is accurate. The one that came with my kit was reading High by 10 psi. More than enough to throw out static and running pressures. I had to compensate by going by gauge readings 10 psi lower. So make sure that gauge is accurate.

 

[Hvyleaf]

If you don't have a proper refill unit the best way to judge, is by static pressure. To do this the car needs to sit overnight and acclimatize to Environmental temperature. Make sure the windows are open. So first thing in the morning take an accurate thermometer. Then check the exact temperature. Now connect your refill can with the pressure gauge attached to the low pressure valve. Check with the pressure, without the system having run. Then compare the temperature and pressure to the available charts for freon type. I've attached one for R134.

Make sure the gauge is accurate. The one that came with my kit was reading High by 10 psi. More than enough to throw out static and running pressures. I had to compensate by going by gauge readings 10 psi lower. So make sure that gauge is accurate.

Thank you, I think I follow. Let it sit overnight, and check the temperature that’s blowing out of the vents? And compare?

The gauge I’m using is the 15 acpro brand one and I used a cheap supertech can.

Ambient air temps around 85-90 The gauge would be in the red zone after filling, with ac off , roughly 65/75 psi. Would be around 45/50 while running then drop to about 20/25 when the clutch tried to engage, going back up.

Since it’s blowing cooler but not cold, I’m gathering the gauge is inaccurate as was your experience.

Man, I’m almost willing to pay to have it done professionally, I just don’t like people working on the SHO for some reason,
even though at the end of the day, a car is a car.

A/c rehaul is something a little more than I’m willing to take on with the limited space I have at the moment. So I should just bite the bullet

 

[Bluezone]

No don't run the car or the air conditioning. You're checking the static pressure, non-running. The pressure changes according to temperature. So you want the engine cool and the air conditioner undisturbed. If the right volume of freon is in the system, the pressure will reflect the temperature of the surrounding environment. Suggest you do it in the morning. The reason you open the car windows is the inside temperature of the car needs to be the same as well. The temperature differential will effect the pressure.
Watch this video it'll tell you what I've been talking about.
Make sure you use the correct chart for the type of freon you're using. The one I supplied is for R134. With different types of freon the pressure at temperature specifications is different.

 

[luigisho]

I think I easily spent over 1k having my ac system overhauled at a shop some years ago. That was new everything including NOS compressor. That was my last car and my current car needs ac work now. Ford systems with all the o-ring connections suck.

 

[rubydist]

And please note that the chart supplied by Bluezone has the air temperature in Celsius not *F

 

[Bluezone]

And please note that the chart supplied by Bluezone has the air temperature in Celsius not *F

Actually it has both Fahrenheit and Celsius on it. 32° F or freezing is zero degrees Celsius. 50° f is equal to 10 degrees Celsius. Etc etc

 

[rubydist]

That's curious, the one I downloaded only seems to show *C.

 

[Bluezone]

Strange, it would appear I have provided the wrong chart. Apologies.
Almost the same title.

 

[Hvyleaf]

No worries. Thank you. So far I’ve located a small leak on the lowside from the schrader valve

 

[luigisho]

No worries. Thank you. So far I’ve located a small leak on the lowside from the schrader valve

Common leakage place..along with a bunch of others.

 

[Tbird6]

The car should have UV dye in the refrigerant from the factory. So just use a black light to inspect for leaks. I find doing it in a dark garage the best. Not easy to see if you have sunlight blinding you.
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[NoSlo]

Strange, it would appear I have provided the wrong chart. Apologies.
Almost the same title.

Just checked mine. At 71F, 72 PSI on the bottle's gauge, R134A retrofit. Just have to ponder why it doesn't cycle, only pulls the low side down to 25 and sits there.