New ToughOne Compressor + Dryer + Firestone recharge = Cool not Cold

[Evan6ardner]

Title pretty much sums up what I did.


I swapped out the compressor and dryer and orifice filter. I went to Firestone and had them recharge the system. They claimed to have used 31oz of r134a.

Anyway, the mechanic made a note that the compressor was cycling on/off, but didn't really say frequency. I told them when I picked it up that it was normal, because I recall hearing the compressor click on/off every so often.

Anyway, I measured static pressure: 90psi h/l. I measured pressure while idling and it was 35/200 on a 90-95F day. The dryer is cool, but previously it was VERY cold to touch and would drip condensation.

I don't know what to do at this point. I doubt the new compressor is the issue.

 

[hasoan]

I swapped out the compressor and dryer and orifice filter. I went to Firestone and had them recharge the system. They claimed to have used 31oz of r134a.

How much is it supposed to take? check the label under the hood if you dont know.

Anyway, I measured static pressure: 90psi h/l.

That would suggest if not contaminated, that the temperature of the R134a is about 82F. was the temperature outside rising when you took that measurement? Also, that number is almost useless unless the car has sat overnight.

I measured pressure while idling and it was 35/200 on a 90-95F day.

Is that with cycling? in other words, 35 is the lowest the low side goes, and 200 is the highest the high side goes?

It could be low on charge, or something else... but, If its 90-95 degrees out, I know my AC takes a while to get the car cold on MAX AC.

 

[Evan6ardner]

Okay, so I'm pretty sure I have a leak, and those *@#)(*&!@ at firestone didn't really check at all. I'm going to have words with them.

I checked my pressures again while running, and now it was down to 20-25 psi low and 150 high. It was 35/200 a day or two afterwards. I can hear a hiss when I shut my truck down, but I tried squirting soapy water at the connections I disconnected to change the accumulator and the orifice tube and I couldn't find any bubbling. Should I go ahead and add a dye to it? Any suggestions? Man that ticks me off. Is a hiss normal after shutting down? I don't think so. My guess is the high side line gets pressurized to 150 and just hisses until the psi drops.

Oh, and now the compressor is cycling on/off every 5-10 seconds.

 

[hasoan]

Okay, so I'm pretty sure I have a leak, and those *@#)(*&!@ at firestone didn't really check at all. I'm going to have words with them.

I checked my pressures again while running, and now it was down to 20-25 psi low and 150 high. It was 35/200 a day or two afterwards. I can hear a hiss when I shut my truck down, but I tried squirting soapy water at the connections I disconnected to change the accumulator and the orifice tube and I couldn't find any bubbling. Should I go ahead and add a dye to it? Any suggestions? Man that ticks me off. Is a hiss normal after shutting down? I don't think so. My guess is the high side line gets pressurized to 150 and just hisses until the psi drops.

Oh, and now the compressor is cycling on/off every 5-10 seconds.

There hiss is normal for maybe 30 seconds after shutting off. I had never noticed it myself until I recharged my AC, and thought I had a leak somewhere. I didn't. I think its just the evaporator or accumulator boiling off whats left of the liquid R134a. If it was leaking that loud, you'd probably have none left by now.

BTW, If you plan to add dye, you will have to add refrigerant to get it in the system. If you do that, I suggest you only add a very small amount. like one compressor cycle. If it stops cycling because you are adding more, then just a few seconds.

Alternatively, you can wait a few days and see if the compressor cycling keeps getting faster. when there is only just enough R134a in there to allow the compressor to kick on, it will cycle on like for only a second.

I can't say what the Firestone place did, but I sometimes feel that shops like that don't care to be as thorough with people who obviously did most of the work themselves. They know you are not going to give them much business.

Also, It takes time to test for leaks. 30 minutes bare minimum, but overnight is better. I'm not sure I'd want to waist time troubleshooting someone elses repairs if they are just going to go home and fix it themselves. I'm just saying I understand that perspective.

One last Question: Why did you swap out the compressor to begin with? What was the initial problem you were trying to fix?

 

[Maniak]

There hiss is normal for maybe 30 seconds after shutting off. I had never noticed it myself until I recharged my AC, and thought I had a leak somewhere. I didn't. I think its just the evaporator or accumulator boiling off whats left of the liquid R134a. If it was leaking that loud, you'd probably have none left by now.

BTW, If you plan to add dye, you will have to add refrigerant to get it in the system. If you do that, I suggest you only add a very small amount. like one compressor cycle. If it stops cycling because you are adding more, then just a few seconds.

Ditto on the hissing.. Its normal for a minute after you shut off the vehicle (if the a/c is running). It is equalizing the pressure..

As for dye. I always use oil with dye in it. That way if I get a leak over time I know where it is right away.. Even when using a sniffer it takes a while to pinpoint a leak.

What I do to see if it is the low pressure that is causing the cycling (which it probably is), to to just take the low pressure sensor connector off and add a jumper wire. It if stops cycling then it is low on pressure. If it continues to cycle it is being told to turn off by something up stream like the WOT (wide open throttle) cutout or the a/c head (heater/ ac control)

~Mark

 

[Evan6ardner]

One last Question: Why did you swap out the compressor to begin with? What was the initial problem you were trying to fix?

The clutch started rattling sporadically.

I thought about just replacing the clutch, but then I wasn't 100% sure if there were any bearings within the compressor itself that would have been affected, so I said screw it: I'm replacing the entire compressor with the clutch (ToughOne w/ Coupon at AA was $135).

My truck has 220k on it. I didn't mind swapping out the compressor because I assumed if the clutch went bad, the compressor may be 10-20k from the same fate.