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Author Topic: LG LFX31945ST French Door low side in vacuum capillary tube issue?  (Read 1687 times)

Offline houptee

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  • Member Since: Jan 2010
  • Posts: 100

Hi I got this 2014 used LG fridge in excellent condition the woman said it needs a compressor.
Found service valves have been brazed onto compressor suction line and high side on the filter dryer stub.
No pressure was in the system and saw dye had been added.
Used black light and saw dye in the condensate drain pan water.
Checked evaporator in fresh food section and saw dye all over the coils and dripping into drain pan.
Looked like the aluminum to copper transition crimp was the leak.
Checked freezer evaporator looked fine no sign of dye.
Ordered brand new evaporator assembly since it comes with the defrost heater and sensors and wire harness all attached so decided to go ahead and replace freezer evaporator at same time as I read the defrost heaters get weak over time and I had it all apart already.

When i removed the black tape sealant that they wrap around the brazes to cut the tubing i noticed what looked like damage to the capillary tube just above the braze it felt like someone pinched it with side cutters but looking closer it looks like a factory made pinch off crimped on the capillary tube so its like a tiny orifice made with some type of tool.

Looked at the freezer capillary tube and has the same tiny crimp mark you can feel it with your fingernail.

I wasn't sure if last person working on this did that or if it was factory made crimp.

I cut and filed and used tiny pick tool made sure cap tube was open (below these tiny crimps).

I used Stay Brite 8 to silver solder in the two new evaporators, pulled vacuum for 1 hr and charged with 134a 5 oz.

System is running low side in 20 in hg vacuum and High side 110 psi left it overnight running and fridge is hot inside.

Pulled power cord pressures do not equalize at all low side stays in vacuum with power off.

Obviously a restriction but does anyone know about these tiny crimps are they supposed to be there in the cap tubes?

Or possibly the drier is clogged maybe the last guy used sealer dye to stop the leak and clogged either the cap tubes or drier with it.

PS this is the LG that uses a reversing valve by the linear compressor to direct the flow to each evaporator.
Compressor sounds good and no flashing error led on main board and no errors on front panel.

Thanks!

Offline houptee

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  • Member Since: Jan 2010
  • Posts: 100
Re: LG LFX31945ST French Door low side in vacuum capillary tube issue?
« Reply #1 on: August 21, 2018, 09:43:20 AM »
I posted this question on another help board and this guy replied to me.

Posted by UmmScott

YES....LG puts that pinch in the cap tubes from the factory.

From what Ive been told, they put that pinch in there so you don't hear the sound of refrigerant flowing/equalizing during the off cycle.
Lg said to remove said pinched area and that should take care of the restriction.

That was me talking to LG tech support a few years ago. Idk how i even made it that far because you're supposed to be factory authorized...etc...blah blah blah...

He said on some units they over-pinched that area and caused too much of a restriction OR something gets stuck at the pinch causing a complete blockage

Offline houptee

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  • Member Since: Jan 2010
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Re: LG LFX31945ST French Door low side in vacuum capillary tube issue?
« Reply #2 on: August 22, 2018, 03:02:18 PM »
https://photos.app.goo.gl/PSzuHP8fRAiD7Z8YA

Photos of the crimp marks on capillary tubes etc.

Offline dewitt8884

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  • Member Since: Apr 2014
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Re: LG LFX31945ST French Door low side in vacuum capillary tube issue?
« Reply #3 on: August 22, 2018, 08:51:04 PM »
Wow, I've not heard about this at any of the factory training. Thanks for sharing.

Offline houptee

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  • Member Since: Jan 2010
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Re: LG LFX31945ST French Door low side in vacuum capillary tube issue?
« Reply #4 on: August 24, 2018, 06:31:53 PM »
I think the problem is the 3 way valve. What would happen if you just pipe these fridges and bypass the 3 way so it cools both evaporators all the time? Or will the main board shut down the unit since it cant control the temps properly and throw codes?

Offline houptee

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  • Member Since: Jan 2010
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Re: LG LFX31945ST French Door low side in vacuum capillary tube issue?
« Reply #5 on: August 25, 2018, 05:45:40 PM »
LG dual evaporator training document and other LG appliances from a 2011 class I believe

https://applianceassistant.com/ServiceManuals/lg_fall2011_ha_trainingmanual.pdf

Offline houptee

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  • Member Since: Jan 2010
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Re: LG LFX31945ST French Door low side in vacuum capillary tube issue?
« Reply #6 on: May 11, 2019, 12:48:32 AM »
LG capillary tube replacement bulletin attached.

Offline houptee

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  • Member Since: Jan 2010
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Re: LG LFX31945ST French Door low side in vacuum capillary tube issue?
« Reply #7 on: May 19, 2019, 11:15:31 AM »
LG Linear Compressor quick troubleshooting guide. Written by a LG appliance technician.

Offline houptee

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  • Member Since: Jan 2010
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Re: LG LFX31945ST French Door low side in vacuum capillary tube issue?
« Reply #8 on: August 11, 2019, 06:22:57 PM »
LG has a new compressor and software update that must be done to the mainboard that supposedly fixes the issues.
Part numbers to order one is LG Compressor TCA38091801 & Software Jig TCA35911910
Compressor has a purple decal and red decal on top warning about the software update.

FLS075LANA is the new compressor model number
It replaces these older LG/Kenmore Elite compressor versions:
FC75LBNA
FLA075LANA
FLB075LANA
FLB075LBNA

Offline RyanAZ

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  • Member Since: May 2020
  • Posts: 2
Re: LG LFX31945ST French Door low side in vacuum capillary tube issue?
« Reply #9 on: May 13, 2020, 05:56:10 PM »
Have you guys had any experience with the new LG Compressor TCA38091801?  Are they curing the chronic failures of the fridges?  or is it a temporary repair to a permanent problem?  I have a Kenmore 795.74022 (2017 model) with the typical linear compressor failure.  I am currently evaluating my repair options.  Any thoughts/opinions would be appreciated.

Offline Pnwdad1981

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  • Member Since: May 2020
  • Posts: 55
  • Country: us
  • Professional appliance tech for over a decade
Re: LG LFX31945ST French Door low side in vacuum capillary tube issue?
« Reply #10 on: May 13, 2020, 08:15:32 PM »
When ordering the new universal compressor you need to check the list of cross compatibility. There's a few that you can't use it as the boards algorithm won't work and then there's the Pcbs that don't require the flash then there's the Pcbs that you have to ohm out the Con201 rewrite port cause it's not marked with the Rx or TX. And yes your right the cap pinch to to deaden inrush and from what I heard sometimes you can use a lighter and heat the restriction to bypass if your lucky.  I think I'm rounding about 150 801 comp repairs. Haven't been back to any yet.... Just dont forget to unplug the fridge before flashing the software and see if the pins position match the 801 which they never do so you have to flip the plug counter clockwise one pin. Good luck
🌲PNW Chris🌲

Offline smdan

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  • Member Since: May 2018
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Re: LG LFX31945ST French Door low side in vacuum capillary tube issue?
« Reply #11 on: May 17, 2020, 12:03:57 PM »
Have seen a lot of the LG fresh food evaps leak, whenever i change one out I cut right above that crimp to prevent any future possible restrictions. Make sure you always put it in test mode 1, wait 15 seconds and unplug fridge before doing any sealed system work so the 3 way valve is open for both evaps.  Because of the ck valve, you gotta cut the 2 cap tubes at the 3 way valve and send nitrogen from the frzr and ff evap side to clear any restriction. To avoid all that i usually run R11 thru the system and clear it with nitro out of the discharge line. I have seen the condensers clog up more often than a restriction in the cap tube though on these.