AC Leak? (1 Viewer)

[JCollin]

We headed out from Texas toward Colorado today and a few hours in the AC stops cooling. It was a meat locker and I had it on recirculate so it took it a bit before we knew something was wrong. Pulled over and popped the hood. AC clutch is engaging and turning when the button is pushed. I stuck a gauge on it and it showed extremely empty. I emptied 2 mid size cans of R-34 into it and nothing. No pressure increase on the gauge. All fuses were good. Compressor still kicks on so shouldn’t be relay. One note…a few minutes before it got warm I heard a little thud under the hood. I was positive it was the belt, but belts are good. Is there some sort of pressure relief valve somewhere, like on a boiler? (Sorry, I’m a plumber). Maybe a line or fitting busted? Seemed weird to be so sudden and compressor still working and belt good. Any advice would be great. Luckily, we’re heading to an area where we won’t need it. But unfortunately, we have to come back to The Texas Heat Dome of 2023. TIA

 

[truthdetector]

It's strange that the clutch is spinning if the system is empty. I thought that if there is no pressure in the system it won't send voltage to the clutch. Following to see what ends up being the problem.

 

[BILT4ME]

We headed out from Texas toward Colorado today and a few hours in the AC stops cooling. It was a meat locker and I had it on recirculate so it took it a bit before we knew something was wrong. Pulled over and popped the hood. AC clutch is engaging and turning when the button is pushed. I stuck a gauge on it and it showed extremely empty. I emptied 2 mid size cans of R-34 into it and nothing. No pressure increase on the gauge. All fuses were good. Compressor still kicks on so shouldn’t be relay. One note…a few minutes before it got warm I heard a little thud under the hood. I was positive it was the belt, but belts are good. Is there some sort of pressure relief valve somewhere, like on a boiler? (Sorry, I’m a plumber). Maybe a line or fitting busted? Seemed weird to be so sudden and compressor still working and belt good. Any advice would be great. Luckily, we’re heading to an area where we won’t need it. But unfortunately, we have to come back to The Texas Heat Dome of 2023. TIA

No, there is no pressure relief on it.

Is the clutch actually engaging? Or are you seeing the pulley spinning?

A pop is typically something blowing out like a seal.

If you put gauges on it and you have no pressure, then it's an open system unless something wasn't hooked up and open properly.

Did you smell anything funky inside while driving? I've heard it described as a smell of Band-Aids from long ago.

Could it still be operating but a blend door slammed shut?

What year and model?

If it blew a seal or a line, you should hear or smell the freon going into it again if you dumped in two more cans.

 

[JCollin]

No, there is no pressure relief on it.

Is the clutch actually engaging? Or are you seeing the pulley spinning?

A pop is typically something blowing out like a seal.

If you put gauges on it and you have no pressure, then it's an open system unless something wasn't hooked up and open properly.

Did you smell anything funky inside while driving? I've heard it described as a smell of Band-Aids from long ago.

Could it still be operating but a blend door slammed shut?

What year and model?

If it blew a seal or a line, you should hear or smell the freon going into it again if you dumped in two more cans.

Thanks for the reply. It’s a 96 80 series. Yes, the clutch engages and disengages with a pop when the AC button is pressed on and off from the inside.
I dealt with AC hell in my Powerstroke several years back and remember that smell vividly. I didn’t smell anything in the cab when it started not cooling. We were on the highway doing 70+ though, so if it was a line or seal under the hood, maybe it dispersed in the wind and we couldn’t smell it ?

When I added to the system I was standing on the front bumper with it running, I assumed it was working just like every other vehicle I’ve added refrigerant to. It was loud and the fan was blowing hard so I didn’t hear anything. My wife was inside the cab and said it never got cool. I wonder if it was leaking out as fast as I’m putting it in that it would dissipate quickly enough that I couldn’t smell anything or hear anything when I hopped down off the bumper?

 

[BILT4ME]

Thanks for the reply. It’s a 96 80 series. Yes, the clutch engages and disengages with a pop when the AC button is pressed on and off from the inside.
I dealt with AC hell in my Powerstroke several years back and remember that smell vividly. I didn’t smell anything in the cab when it started not cooling. We were on the highway doing 70+ though, so if it was a line or seal under the hood, maybe it dispersed in the wind and we couldn’t smell it ?

When I added to the system I was standing on the front bumper with it running, I assumed it was working just like every other vehicle I’ve added refrigerant to. It was loud and the fan was blowing hard so I didn’t hear anything. My wife was inside the cab and said it never got cool. I wonder if it was leaking out as fast as I’m putting it in that it would dissipate quickly enough that I couldn’t smell anything or hear anything when I hopped down off the bumper?

It could be you are over pressurized. They will stop cooling then, as well.

I'm calling @flintknapper to the crime scene. He'll figure it out.

 

[Hornd]

Get a set of Gauges on it and Post up picture of High and Low Side Pressure Ports and we can get an idea of what is going on.

If you don't have Gauges buy a Set or Find a Shop that Does.

If you want to do this Right your Gonna need to Rent a Vacuum Pump too (Autozone)

I also recommend Getting some PAG46 Oil with UV Dye.

 

[flintknapper]

IF you don't need A/C while in Colorado or elsewhere along your trip....then just wait until you get back home (Texas, it is sweltering here). If you need A/C before that (can't imagine you would not) I recommend you take it to a shop and have them diagnose it.

From what you describe there is a lot to check out.

At the very least, a 'good' set of manifold gauges need to be connected to the low and high side circuits so a reading of the 'static' pressure (engine and system off) can be taken.

This will tell us IF there is enough pressure (minimum) to allow the binary switch to complete the circuit and engage the clutch. I find it odd that the compressor clutch is actually engaging with little to no pressure showing on the low side.

IF the low reading was obtained via a 'gauge' on one of those charge cans you can buy, then we can throw that out the window.

From what we've been told....the compressor IS engaging and you have managed to introduce 2 cans of refrigerant into the system.

So at this point (depending on pressure reading) you either have a leak of epic proportions or you are overcharged.

There is a 'binary' pressure switch (High/Low) in the high side line just in front of your battery which 'should' allow or disallow the compressor clutch to engage. If there is not enough system pressure (low pressure)....OR too much pressure (high pressure) the switch will prevent the compressor clutch from engaging.

IF your clutch is actually engaging then we can assume:

1. The binary switch is working properly.
2. Your fuses and Relay are working (except that a relay can fail intermittently).
3. The wiring and dash controls (that call for the compressor) are working.
4. The system has 'some' refrigerant in it....but we have no idea the amount.

I would first be inclined to check the air gap of the compressor clutch (should be around .020). If the gap is too large the clutch is slipping.

I would jumper across the leads to the clutch to visually establish the clutch is engaging (this will be audible as well).

IF no issues are found there....I would turn to the manifold gauges, take a static reading first then with system running give us high and low pressure readings.

If you have very high, high pressure readings and low (to none) on the low side....then you have an obstruction or TXV stuck shut.

We can walk you through as many troubleshooting processes as you like and are happy to do so, but much easier for you to take it to a reputable shop and have them diagnose it. They will have all the tools necessary.

 

[JCollin]

IF you don't need A/C while in Colorado or elsewhere along your trip....then just wait until you get back home (Texas, it is sweltering here). If you need A/C before that (can't imagine you would not) I recommend you take it to a shop and have them diagnose it.

From what you describe there is a lot to check out.

At the very least, a 'good' set of manifold gauges need to be connected to the low and high side circuits so a reading of the 'static' pressure (engine and system off) can be taken.

This will tell us IF there is enough pressure (minimum) to allow the binary switch to complete the circuit and engage the clutch. I find it odd that the compressor clutch is actually engaging with little to no pressure showing on the low side.

IF the low reading was obtained via a 'gauge' on one of those charge cans you can buy, then we can throw that out the window.

From what we've been told....the compressor IS engaging and you have managed to introduce 2 cans of refrigerant into the system.

So at this point (depending on pressure reading) you either have a leak of epic proportions or you are overcharged.

There is a 'binary' pressure switch (High/Low) in the high side line just in front of your battery which 'should' allow or disallow the compressor clutch to engage. If there is not enough system pressure (low pressure)....OR too much pressure (high pressure) the switch will prevent the compressor clutch from engaging.

IF your clutch is actually engaging then we can assume:

1. The binary switch is working properly.
2. Your fuses and Relay are working (except that a relay can fail intermittently).
3. The wiring and dash controls (that call for the compressor) are working.
4. The system has 'some' refrigerant in it....but we have no idea the amount.

I would first be inclined to check the air gap of the compressor clutch (should be around .020). If the gap is too large the clutch is slipping.

I would jumper across the leads to the clutch to visually establish the clutch is engaging (this will be audible as well).

IF no issues are found there....I would turn to the manifold gauges, take a static reading first then with system running give us high and low pressure readings.

If you have very high, high pressure readings and low (to none) on the low side....then you have an obstruction or TXV stuck shut.

We can walk you through as many troubleshooting processes as you like and are happy to do so, but much easier for you to take it to a reputable shop and have them diagnose it. They will have all the tools necessary.

Great feedback, thank you for that. I think with this being an anniversary trip, I’ll focus on camping for now. We are going to finish out the trip (Thurs-Saturday) at a condo in Telluride. Might see if I can find a shop there.

 

[JCollin]

By the way…if ANYONE has connections to a shop in Telluride, that would be incredible and I would be forever in your debt and will dance at your wedding.