R134a (LG style refrigerator) static pressure = 10" vacuum

[Space]

Couple months ago, our fridge ceased cooling. Called a repair dude, he came in says it's either leaking or plugged, he installed a piercing valve on the low side and topped it off and overcharged for good measure. That lasted 3 weeks. I assume I have a leak. I bought a can of 134a and an adapter hose on Amazon. I attempted to recharge it to 3-5psi, which I did, but got very little cooling out of the freezer and it went warm again. I borrowed a gauge set and decided to check and see where it sits right now, and was going to pressurize and see how fast it leaked out. I hooked it up with it not running, and it sits at 10in vac. If it was leaking, shouldn't it at least show 0psig? It hasn't been ran in a week. I assume the entire system would equalize in pressure and I should at the very least read 0 or slightly positive. I didn't fire it up yet, I was curious as to how I could have a leaky fridge stuck in a vacuum. The piercing valve is not on the high or low lines, but on the extra nub of line on the compressor.

Is the charge (~6 oz) so small that it will not give an accurate static reading?

Is there blockage in the filter drier or capillary tube?

Could it leak out, but not in? ie self sealing when there's no pressure in lines

It's a 5 year old (just out of warranty of course) Kenmore Elite 79571053012

[Hiroshi]

If your refrigerant leaked out that fast, it is a high side leak. "Overcharging" is something that shouldn't be done, and certainly not "for good measure." Overcharged systems will not cool properly either... 

 

[Space]

Well aware of that, just stating the facts of what went down. It's odd because he wouldn't put dye in because he believes only refrigerant and oil should only be in there, but has no problem doing that. I'm starting to lean towards a blockage what with the vacuum reading and all. I cannot confirm nor deny that the high side is leaking as of right now. Someone showed me a braze in filter drier with an access port I might put in, but as far as the capillary tube, any idea how difficult that would be on this unit? Is length a closely engineered spec?

[lvasquez11]

Do you a tech sheet on unit , running pressure is listed on tech sheet.

when charging on process stub with unit running the suction will cause u to over charge. What did u use to scale charge

Start unit up n post pressures.

You also might have a linear compressor with bad valves

Edited July 21, 2016 by lvasquez11

[Space]

I do not have a tech sheet, and I did not measure the charge, I went strictly off of the low side pressure. I will post a pressure with it running perhaps tomorrow or so, I took the gauge off and pushed the fridge back.

 

[Space]

I hooked up the gauge, it was still reading 10" vac. I plugged in the fridge, and nothing changed on the gauge. Could barely tell if the compressor was running, was a slight vibration on the housing. I unplugged the fridge, put 9psi of refrigerant on the gauge and fired it back up. It slowly, but not smoothly, kind of choppy, went back down into a vacuum. I unplugged it and put 36 psi on it and will check to see if it holds. I'm going to have to break the system at this point. Just need to know what Im going to do exactly. I'm going to pick up some braze in ports and see if I can get me a torch. I'm ultimately going to remove the saddle piercing valve and will probably braze in a low and a high side.
Will pressure test with N2 and see what I can find out. Is there any recommendation on location for low side and high side valves? I see there's an excess stub on the filter that could probably serve as a high side location. Is there an alternative to using a full on oxy-acetylene torch setup to braze? I could probably borrow some large tanks and transport them here. I don't have the small bottles, nor know anybody that does.

For full disclosure, I've been using a can of automotive 134a with leak seal. I don't imagine I got too much of the sealant in the system as I havent emptied the can, nor charged in liquid form, but it probably is floating around in the system.

[certified tech group 51]

Space, you are doing a lot of guessing......First you need all of the correct tools....Process  port is attached to the compressor at the "stub" on the compressor, low side..........The High side port is  installed at the filter dryer...A new filter dryer with a port...( could be just a restricted cap tube )...I have installed a process tube adapter at the tubing, just before the filter dryer, to check the P.S.I. out of the compressor........ Evacuate the system down to 30 in. HG. .............This is  to remove all the crap, your hack of a service dude  and you are introducing into the system.....After a few 20 minute cycles.....Add 150 P.S.I. of DRY nitrogen......watch the high side gauge,  Does the P.S.I. stay the same for 24 hours?????....Depending on how fast the pressure drops is relative on the hole size.......The amount of refrigerant is listed on the S/N label in the unit.......There is a difference in the quality of R 135A from automotive and the refrigerator R134A....

[Space]

I'm aware I need the tools, waiting on all that at the moment. Using what I have to check for leaks. The pressure did drop to about 25 psi within an hour. I started spraying big blu everywhere I could. The evaporator, condenser,filter,compressor braze joints, my line and valve. Got nothing at the moment.

[BrewHobbyTech]

On 7/26/2016 at 3:04 PM, certified tech group 51 said:

.......There is a difference in the quality of R 135A from automotive and the refrigerator R134A....

Please inform me of this difference. The reason this caught my eye is because I've never seen R135A, or anything marked as that. If I am ignorant, please inform me.......I seek knowledge......and seek the truth.........

[BrewHobbyTech]

On 7/19/2016 at 0:18 AM, Space said:

Couple months ago, our fridge ceased cooling. Called a repair dude, he came in says it's either leaking or plugged, he installed a piercing valve on the low side and topped it off and overcharged for good measure. That lasted 3 weeks. I assume I have a leak. I bought a can of 134a and an adapter hose on Amazon. I attempted to recharge it to 3-5psi, which I did, but got very little cooling out of the freezer and it went warm again. I borrowed a gauge set and decided to check and see where it sits right now, and was going to pressurize and see how fast it leaked out. I hooked it up with it not running, and it sits at 10in vac. If it was leaking, shouldn't it at least show 0psig? It hasn't been ran in a week. I assume the entire system would equalize in pressure and I should at the very least read 0 or slightly positive. I didn't fire it up yet, I was curious as to how I could have a leaky fridge stuck in a vacuum. The piercing valve is not on the high or low lines, but on the extra nub of line on the compressor.

Is the charge (~6 oz) so small that it will not give an accurate static reading?

Is there blockage in the filter drier or capillary tube?

Could it leak out, but not in? ie self sealing when there's no pressure in lines

It's a 5 year old (just out of warranty of course) Kenmore Elite 79571053012

I only did a quick search on this model, so I could be wrong......but is this a dual evaporator system??  These are a different animal all together, and not many people are willing to work on these units. I do have some experience and will try to help you, but it's late and I really need to get to bed. If I have time I'll try to get back to this thread in the next few days. I may need to ask a few more detailed questions. These fridges are a bitch though........and that's an understatement.......

[certified tech group 51]

No known "as a fact" paper on the difference, but,  as the story goes..............Not filtered as much and if you get a hold of the stuff made in China, it could have impurities /oils  in it...............not regulated as good as the USA stuff..........It would be a difficult story to tell the customer that when you used automotive R134a and the refer quit......The refer could have been on it's way out already but the customer only sees that you killed it, you gotta replace it.....alotta tap dancing going on..... 

[Ressane]

On 7/18/2016 at 10:18 PM, Space said:

Couple months ago, our fridge ceased cooling. Called a repair dude, he came in says it's either leaking or plugged, he installed a piercing valve on the low side and topped it off and overcharged for good measure. That lasted 3 weeks. I assume I have a leak. I bought a can of 134a and an adapter hose on Amazon. I attempted to recharge it to 3-5psi, which I did, but got very little cooling out of the freezer and it went warm again. I borrowed a gauge set and decided to check and see where it sits right now, and was going to pressurize and see how fast it leaked out. I hooked it up with it not running, and it sits at 10in vac. If it was leaking, shouldn't it at least show 0psig? It hasn't been ran in a week. I assume the entire system would equalize in pressure and I should at the very least read 0 or slightly positive. I didn't fire it up yet, I was curious as to how I could have a leaky fridge stuck in a vacuum. The piercing valve is not on the high or low lines, but on the extra nub of line on the compressor.

Is the charge (~6 oz) so small that it will not give an accurate static reading?

Is there blockage in the filter drier or capillary tube?

Could it leak out, but not in? ie self sealing when there's no pressure in lines

It's a 5 year old (just out of warranty of course) Kenmore Elite 79571053012

I have the same exact problem with the same exact fridge. Recharged it ..still no cooling. I'm suspecting bad compressor valves !

[ECtoFix]

On 5/17/2020 at 11:09 AM, Ressane said:

I have the same exact problem with the same exact fridge. Recharged it ..still no cooling. I'm suspecting bad compressor valves !

A couple of points to mention here:

1. Recharging without knowing leak location, repairing it, evacuating the system and weighing in a new charge RARELY yields desired results.  By not knowing the location of the leak and if it so happened to be on the low side of the system, there will probably be non-condensables in there (air) that got drawn in when the low side pulled down below 0psi.  A system with air in it will NEVER work properly.
2. The only sure way to determine whether compressor valves are bad is to connect gauges to BOTH - the low side AND the high side, in order to monitor pressures during system operation. 

[Terry Carmen]

On 7/19/2016 at 12:18 AM, Space said:

Called a repair dude, he came in says it's either leaking or plugged, he installed a piercing valve on the low side and topped it off and overcharged for good measure.

If nothing else, I'd get your money back, since the tech didn't actually diagnose the problem, and the "fix" he performed would not have repaired either of the problems he mentioned, and if he added enough gas, would cause additional damage. Modern compressors don't handle overcharges well..

It's like saying "Your car has a flat tire or a dead battery. I'll just set it on fire for you".

 

Edited May 18, 2020 by Terry Carmen

[vunger1]

On 5/18/2020 at 4:17 PM, Terry Carmen said:

If nothing else, I'd get your money back, since the tech didn't actually diagnose the problem, and the "fix" he performed would not have repaired either of the problems he mentioned, and if he added enough gas, would cause additional damage. Modern compressors don't handle overcharges well..

It's like saying "Your car has a flat tire or a dead battery. I'll just set it on fire for you".

 

Haha this made me laugh, nothing like being extreme to drive home a point.

[g schlag]

Hi guys new member here I have the same problem with a Kitchenaidrefrigerator. My unit has what looks like a txv.so it I am getting the gist of what you are all saying I will have to put a access

port or high side port ( so that we can see the high side pressure ) on the high side line but where. I think it has a dryer so

I will go out and look later if it does I will get a dryer with a port on it.

Are these manufacture specific or can I use a generic one and if so what would you recommend.

I am thinking of replacing the txv is this necessary.

As of right now I have a vacuum on it 30+ inches of Hg.

Been holding for 2 hours so I will let it sit over night and see if it drops.