AC not accepting freon

Gli_ryan

Member
Joined
Apr 14, 2019
Location
Idaho
TDI
B4v
So the ac doesn’t work for more than half a minute in my ‘96 b4v. The compressor kicks on and stays on. I can feel the air changing temps from the vents. Before the air really gets cold it warms back up. This happens when parked or at any vehicle speed. The high pressure line condensates in the engine bay and I can see the clutch still spinning on the compressor even though warm air may be coming from the vents. The parts store refill kit shows my refrigerant in the green “filled” area, however it’s on the very bottom of the range. I’ve purchased another bottle and tried to fill the system up more but even after 10 minutes of messing with it I cannot get the system to fill up any more. I know I’m filling/trying to fill it correctly, the line only goes on one fitting.

My hunch is the compressor itself is too weak to work properly and needs replacing. All fans are working and I can feel the air temp change for a short period of time.

Any thoughts or similar problems?
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
please do not and never do use that " cheater can" ever again. Dont trust it, dont even think for a second that the cinisium within is even good enough for a rice rocket!

There are a few things that this chould be and they are electrical.
90% of all HVAC issues are electrical, NOT charge related.
Ambient air temp switch, high pressure / low pressure switch to name a few can trigger a like symptom.

You need to check them all with a multimeter to see if they are functioning properly.

As for your charge, go get a proper set of high and low gauges from harbor freight. You need to tell us the charge at full rest when off and balanced on both sides, the High, the low, the outside air temp, the inside air temp and what pressures are like when it switches off on both high and low and how it equilizes.

only then we can give you some sort of clue as to whats the problem. Putting too much charge in WILL DESTROY your compressor AF. If liquid goes into the compressor it will destroy it very quickly so dont go adding more, and i would not even run it until you have a gauge set on it.
 

Gli_ryan

Member
Joined
Apr 14, 2019
Location
Idaho
TDI
B4v
If the switches are triggered will the clutch not disengage? The system continues to work and build condensation on the high pressure line.
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
Limit switches will keep the clutch from engaging. Is your rad fan running?

Autozone rents the proper gauge set.

-Todd
 

Gli_ryan

Member
Joined
Apr 14, 2019
Location
Idaho
TDI
B4v
The clutch will engage and does stay engaged after the air temp warms back up. The high pressure line continues to condensate as well.

Both fans are running and stay running. At highway speeds the air temp does not stay cool either though.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
The only way to properly charge it, and KNOW it is a proper charge, is with a machine after the system has been evacuated and vacuumed.

However, it sounds like you have a restriction in the system if the high side line is cool. Condenser or drier, or both. But debris generally originates in the compressor, so... you probably need much of the system replaced and what is not replaced flushed out and blown clean.
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
Out of curiosity, what happens if you turn on recirculate?

-Todd
 

ScottSwee

Active member
Joined
May 27, 2019
Location
Santa Fe New Mexico
TDI
05 Jetta wagon MKIV
Oilhammer is correct. You would need to recover pull a proper vacuum and weigh in a proper charge. If the high pressure line is condensating there is a restriction. The high pressure line should never condensate.

You should be able to feel around the lines and find where the refrigerant is changing states This would point to the area of restriction.
 

jhax

Veteran Member
Joined
Jan 24, 2012
Location
Golden, CO
TDI
96 Passat B4V, ALH engine out of a 2002 Jetta, some IE Rods and ASV Pistons. Nothing drivable yet though
I tried the canned r134 on my b4 two or so years ago. I replaced the drier. Poured in some pag oil, bought a vacuum pump from harbor freight, evacuated and refilled. No issues to this day. Since I'm poor, I returned the pump and got money back.
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
I tried the canned r134 on my b4 two or so years ago. I replaced the drier. Poured in some pag oil, bought a vacuum pump from harbor freight, evacuated and refilled. No issues to this day. Since I'm poor, I returned the pump and got money back.
I've done similarly, pulled the system down and let it sit for an hour then fill. I think on this car since the system was empty I put in a can of pag oil too besides what was in the replacement compressor.

I also installed new o-rings on everything. It's been working great.

Steve
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
why the extra oil?
if your system was low on charge or empty, simply pull the compressor up and drain the oil and add new, adding too much oil WILL cause a serious loos of efficiency, its is normal to have a little oil circulating around in the lines and bits but too much will coat and pool up in the coils making less heat transfer, too much oil WILL kill the compressor. you can NOT have a liquid enter into the compressor, only gasses with some oil mist. change that to a flow of oil and your compressor is FUBAR really fast. Granted you have to add a LOT of oil as most of it will end up trapped in the filter dryer. Ever wonder why the car dryers look the way they do vs residential or commercial filter dryers? to trap extra oil that was added. If you go over the ability to hold that oil, well good by AC Compressor RIP
 

jhax

Veteran Member
Joined
Jan 24, 2012
Location
Golden, CO
TDI
96 Passat B4V, ALH engine out of a 2002 Jetta, some IE Rods and ASV Pistons. Nothing drivable yet though
Perfect, so add the recommended amount to the low compression side, 6oz and call it a day
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
why the extra oil?
if your system was low on charge or empty, simply pull the compressor up and drain the oil and add new, adding too much oil WILL cause a serious loos of efficiency, its is normal to have a little oil circulating around in the lines and bits but too much will coat and pool up in the coils making less heat transfer, too much oil WILL kill the compressor. you can NOT have a liquid enter into the compressor, only gasses with some oil mist. change that to a flow of oil and your compressor is FUBAR really fast. Granted you have to add a LOT of oil as most of it will end up trapped in the filter dryer. Ever wonder why the car dryers look the way they do vs residential or commercial filter dryers? to trap extra oil that was added. If you go over the ability to hold that oil, well good by AC Compressor RIP
The system was dismantled and the components all replaced with R134A pieces from misc 95-97 donors.

It was all empty (sans compressor) when it was reassembled.

Steve
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
For future reference the book does give the amount to be added for each component replaced.
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
For future reference the book does give the amount to be added for each component replaced.
I'm sure it does, thank you. TBH I can't recall whether it was a singular pag charge or a combo charge R134A plus pag oil. Whether or not I followed the Bentley info I cannot say, that was some time ago.

I'm sure back in 2015 I took a look at it when I was doing the reassembly but that's water under the bridge and I haven't thought much about it. Could be I used the component amounts to determine how much PAG oil I added, but as I said that was some time ago and I don't remember.

Steve
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
only time it is acceptable to use the PAG oil in the can is when you pull a part like KLXD stated but you have to dump it all and usually those specs are like 2oz for the condenser or 1 once for the evap or 3 for the dryer ECT... i am just swagging those numbers as im not looking at a manual ATM but honestly the really only way to work on a system is to blow it all out clean, purge with nitrogen, add the new filter dryer and go to town on a charge weighed it. its really bad to have more than +/- 5% and one of those cans is what 3 oz i think or is it 5? Anyways, im just really anal about AC systems and i was always told and i always repeat it, the ONLY things that go into the system are pure whatever, no anything mixed, oil is oil, 134a is 134a, if you have to buy a can of a combo or anything that says leak stopper, your just buying time to sell the car to some smuck or wasting more money!
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
only time it is acceptable to use the PAG oil in the can is when you pull a part like KLXD stated but you have to dump it all and usually those specs are like 2oz for the condenser or 1 once for the evap or 3 for the dryer ECT... i am just swagging those numbers as im not looking at a manual ATM but honestly the really only way to work on a system is to blow it all out clean, purge with nitrogen, add the new filter dryer and go to town on a charge weighed it. its really bad to have more than +/- 5% and one of those cans is what 3 oz i think or is it 5? Anyways, im just really anal about AC systems and i was always told and i always repeat it, the ONLY things that go into the system are pure whatever, no anything mixed, oil is oil, 134a is 134a, if you have to buy a can of a combo or anything that says leak stopper, your just buying time to sell the car to some smuck or wasting more money!
KLXD never stated anything about 'pull apart' you're attributing things to other people. And the rant I quoted above...it's no wonder that newbie Gli_ryan hasn't posted back since he joined on the 10th.

I was trained for auto AC work at a tech school back in the 80's and for the most part all that I learned still holds true. You'd probably get triggered if I told you that our instructor taught us to charge with liquid vs gas. He was concerned with shop performance and optimizing income for the shop we would ultimately work for. He was a great guy very smart.

For a complete discussion of anything about the B3V conversion I refer you to this thread where everything (I think) was covered pretty well. I probably didn't discuss AC all that much but I'm sure I covered the part about sourcing all the components.

Stop harping at people, especially new members, and before you post make sure what you're posting is coherent.

Steve
 
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