Low side low, high side high! Help!

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Cusser
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Re: Low side low, high side high! Help!

Post by Cusser »

tbirdtbird wrote: Sat Jun 03, 2023 8:04 am As Tim said, fan shroud will help a lot. If a clutched fan, how old? The viscous coupling wears out (thins out) and will not drive the fan at the correct speed. If new, you are OK. But we have posters here whose only problem is a bad fan clutch.
I swapped out the fan clutches on both my 1998 and 2004 4-cylinder Frontiers in 2022. Seems like they last 6 years in Arizona heat.

tbirdtbird wrote: Sat Jun 03, 2023 8:04 am With a bad fan clutch, the engine will NOT overheat but the AC WILL suffer
Way back in the late 1980s, I had a Toyota truck that ran quite hot in traffic and at idle; it needed just a new fan clutch. I was an "old VW Guy" then, and old VWs ran hotter at highway speeds than in traffic, so I learned that.
Crewcabdart
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Re: Low side low, high side high! Help!

Post by Crewcabdart »

Alright. Made a fan shroud and replaced the fan clutch. Moves a ton of air. Will easily hold a shop towel to the grille. It definitely helped a ton with high side temps, but still can’t charge it enough to keep it from cycling immediately under load.

I also tried letting some Freon out but the situation didn’t change (low side low, high side high)

I’m beginning to think I have some sort of bad TXV/ restriction in the TXV. I can watch the TXV fluctuate by moving the sensing bulb tho. I was banking on that shroud taking care of it.
tbirdtbird
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Re: Low side low, high side high! Help!

Post by tbirdtbird »

"I’m beginning to think I have some sort of bad TXV/ restriction in the TXV. I can watch the TXV fluctuate by moving the sensing bulb tho. I was banking on that shroud taking care of it."

Not sure what you mean by "you can watch the TXV fluctuate"

"I also tried letting some Freon out but the situation didn’t change (low side low, high side high)"

1. Please whenever you respond here with the results of a change we have suggested, or a change you have made, *always* include hi and lo pressures at 1500 RPM, max fan, max cool, recirc, doors open, ambient at least 80F (specify what the ambient is) and specify the vent temp.
This is the only way we can meaningfully help you. We live and breathe by this set of data.

I am convinced it is not properly charged, and suspect you will end up recovering, evacuating, and recharging. We can tell you how to do that properly
When considering your next auto A/C purchase, please consider the site that supports you: www.ACKits.com
Crewcabdart
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Re: Low side low, high side high! Help!

Post by Crewcabdart »

tbirdtbird wrote: Mon Jun 05, 2023 9:14 am "I’m beginning to think I have some sort of bad TXV/ restriction in the TXV. I can watch the TXV fluctuate by moving the sensing bulb tho. I was banking on that shroud taking care of it."

Not sure what you mean by "you can watch the TXV fluctuate"

"I also tried letting some Freon out but the situation didn’t change (low side low, high side high)"

1. Please whenever you respond here with the results of a change we have suggested, or a change you have made, *always* include hi and lo pressures at 1500 RPM, max fan, max cool, recirc, doors open, ambient at least 80F (specify what the ambient is) and specify the vent temp.
This is the only way we can meaningfully help you. We live and breathe by this set of data.

I am convinced it is not properly charged, and suspect you will end up recovering, evacuating, and recharging. We can tell you how to do that properly

My apologies on the lack of numbers. Will get the info you need next time I’m able.

I believe I’m going to evacuate the system, flush to confirm no debris, and replace the TXV and the drier. Unless you have a different suggestion?

If you recommend evacuating, what flush/ flush process would you recommend?
tbirdtbird
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Re: Low side low, high side high! Help!

Post by tbirdtbird »

"I believe I’m going to evacuate the system, flush to confirm no debris, and replace the TXV and the drier. Unless you have a different suggestion?"

Good plan.

Tim the site owner has all manner of parts (comps, dryers, everything) available on his parts site...good quality, good prices
ackits.com

He has an excellent pro flush, I would use nothing less. The gunk you get in the local parts stores leaves a nasty residue...ask me how I know.
Try to blow dry the lines using a bottle of Nitrogen, regular compressed air from a shop compressor is heavily laden with water vapor.
We also paint cars here in this shop and we have all manner of dryers on the line since to shoot auto paint you need really dry air.
Water vapor is your enemy
When considering your next auto A/C purchase, please consider the site that supports you: www.ACKits.com
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