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Low Side 350 PSI & High Side 475 PSI

joshgray01 on Mon June 22, 2009 2:05 PM User is offlineView users profile

Year: 1997
Make: Honda
Model: Accord
Engine Size: 4 Cyl
Refrigerant Type: R-134a
Ambient Temp: 90
Pressure Low: 350
Pressure High: 475
Country of Origin: United States

Okay, I took readings on my friends 1997 Honda Accord, and it was off the charts!!! With the engine on it was 350 PSI (low side) and 475 (high side), and with the engine off about the same. The reason why I was checking out the car was complaints of poor cooling, and after an extended amount of time driving (30 minutes +) the cooling would be intermediate or not at all. However, the A/C compressor clutch would still be active with no cooling. Back to the PSI readings. There was so much pressure on my gauges I thought the hoses were going to break, and I could barley get the high side coupler off of the fitting. Due to so much pressure on the lines. My friend insisted on just adding another can of R134a, but I would not add the can, because I knew it would not help the issue, and the can may blow up in my hand. Anyway, all of the A/C equipment is the original and the car has about 160,000 miles on it. Any ideas?

Thanks,

Josh

joshgray01 on Mon June 22, 2009 2:16 PM User is offlineView users profile

FYI: I should have mention that I asked him if he ever had the system charged/ topped off, and he said no. I asked him twice just to make sure (He still answered no), because he is the type that tinkers with things, then they end up worse off. LOL! Also, he has had the car for over 9 years, with no A/C problems until now. So, if there was not any "topping" off the freon then I am just not sure what the problem can be.

ChevyMan on Mon June 22, 2009 3:50 PM User is offline

I would think that there must be a severe overcharge to make those kind of pressures. I would think that a restriction in the system could cause the high side reading, but the low side should be too low. I just can't imagine any other way to get the low side that high. Is there any way you could have the system evacuated and see how much R134a is in it?

HVargas on Mon June 22, 2009 4:06 PM User is offlineView users profile

Really the only way to get those pressures is to have an extreme overcharge. In most cases if it is blocked like ChevyMan said, you will see the low side start to pull into a vacuum. You need to get all of the freon sucked out to see how much was in the system. Adding a can would be the worst thing you could do.

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When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: Arizona Mobile Air

Chick on Mon June 22, 2009 5:16 PM User is offlineView users profile

Make sure the wheels on the manifold are shut tight when taking pressures, and high side always shut when the ac is on and running..There really isn't any way for the low side to go that high.. unless it's pumping in both directions... hope this helps..

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

ChevyMan on Mon June 22, 2009 5:29 PM User is offline

Was just outside working on my truck. It is very hot here. The static pressure was about 155. The reason I mention this is because on my gauge there is an area at the high end of the scale that goes from 150 to 350 in about 1/2" it is also labeled "RETARD". That means that the gauge is not linear in that area and is not accurate. My high side gauge shows 155 but the low side was where I would have guessed 300 to be. But this was static pressure. Maybe the pressure is not quite as high as you thought.

Anyway, that doesn't really make much difference. Please don't add more refrigerant without finding out how much is in there. Something is very wrong.

joshgray01 on Tue June 23, 2009 9:12 AM User is offlineView users profile

FYI: On the low side it did actually read "Retard" level, while the high side was reading 475 (and climbing). anyway, from the information that I received from ya'll. I will recover the freon, and see how much was really in there. Also, I was thinking it would be a good idea to flush the system, change the receiver/drier, and if needed change the expansion valve. Do you know how to tell if certain condensers, and evaporators can or cannot be flushed, or where to get more detail information on flushing procedures? Also, is there a way to test the expansion valve once it is off the system? Also, does the A/C oil actually leave the system when you recover the freon, or is it for the most part all of the A/C oil still in the system? Thanks in advance!

HVargas on Tue June 23, 2009 12:14 PM User is offlineView users profile

Here is a link to our forum dedicated strictly to flushing Automotive Flushing Forum When you are evacuating the system you do not actually lose any oil. You lose moisture because the vacuum causes the water to boil out of the oil and lines in order to remove it.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: Arizona Mobile Air

Chick on Tue June 23, 2009 5:02 PM User is offlineView users profile

Quote
Originally posted by: joshgray01
FYI: On the low side it did actually read "Retard" level, while the high side was reading 475 (and climbing). anyway, from the information that I received from ya'll. I will recover the freon, and see how much was really in there. Also, I was thinking it would be a good idea to flush the system, change the receiver/drier, and if needed change the expansion valve. Do you know how to tell if certain condensers, and evaporators can or cannot be flushed, or where to get more detail information on flushing procedures? Also, is there a way to test the expansion valve once it is off the system? Also, does the A/C oil actually leave the system when you recover the freon, or is it for the most part all of the A/C oil still in the system? Thanks in advance!

were the wheels on the mainifold closed when reading those pressures? with the compressor running?? had to bleeding over to the low side gauge, can't puump out both ends...

-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

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