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My 97 CH613 AC has had a leak at the Expansion Valve for years so I haven't used the AC in years the last time I tried to charge the system it did blow cold until all refrigerant was out of the system. In my area it’s really hot and now I think it’s time for some AC. I’m asking is it any easy fix to just replace the expansion Valve then charge the system. I have a picture of the expansion Valve that sits on the firewall. What can I use to get the expansion Valve loose I know the bolts will be trouble. Thanks for your help. FF430E8C-0925-4907-94DE-F2188B875BE6.thumb.jpeg.2767cb30bc99cf511845b1306da59fdc.jpeg8EC85C81-D910-4713-B190-F92D5284692C.thumb.jpeg.708c3391740866d51074e50fddeb7b98.jpeg0D01AEAF-D8B8-43B3-AE23-143EE413DAD2.thumb.jpeg.c521b921fda74447f89339f208deba67.jpeg6DDA00BD-29D0-43B1-ACDC-9247A228ADD6.thumb.jpeg.bf2ed0ad84049e96a6b1cf9ebf28e715.jpeg

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Posted (edited)

Unfortunately going to be a can of worms once you start! If you have an impact hammer try massaging the valve at each flare but location and apply a little heat!

Edited by fjh

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6 hours ago, fjh said:

Unfortunately going to be a can of worms once you start! If you have an impact hammer try massaging the valve at each flare but location and apply a little heat!

Is there some type of grease/lubricant I can put on the connections to help with getting it to loosen up? Thanks for your much needed hemp I truly appreciate it. 

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Posted (edited)

you can also try Any type of penetrating oil  again and air hammer on each nut location! You will need to replace the valve of coarse IF you can get it free! Had  luck with this Technic on a Peter built last month! Assembled with neverseaze on the threads !  

Edited by fjh

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39 minutes ago, fjh said:

you can also try Any type of penetrating oil  again and air hammer on each nut location! You will need to replace the valve of coarse IF you can get it free! Had  luck with this Technic on a Peter built last month! Assembled with neverseaze on the threads !  

Great! You have been a great help one more question then I’m on my way to try what you suggested... Will the air hammer damage the lines with all that hammering? And should I place the air hammer between the nuts and the Valve to try and hit the threads? 

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The idea here is to expand the aluminum from around the nut yuo are replacing the valve

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And use a line wrench on the line nuts.

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Okay Hello Guys I did finally get the expansion Valve loose only used line wrenches I have a question before I put it back together the o rings that goes in the expansion Valve is it okay to lubricate with oil it that does not matter? Also sense I don’t have gauges and a big can of R134 can I use the cans you buy from auto zone with the gauges already on the can like AC Pro to charge the system? 

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6 minutes ago, msbulldog601 said:

Okay Hello Guys I did finally get the expansion Valve loose only used line wrenches I have a question before I put it back together the o rings that goes in the expansion Valve is it okay to lubricate with oil it that does not matter? Also sense I don’t have gauges and a big can of R134 can I use the cans you buy from auto zone with the gauges already on the can like AC Pro to charge the system? 

Use PAG, or Ester oil only. Do not use conventional lubricant such as engine oil. Both PAG, and Ester oil are compatible with each other but use the lubricant that is in the system along with the refrigerant. Mineral oil is NOT compatible with R-134A.

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Posted (edited)

You're supposed to put an AC vacuum machine on the system first, and use the same machine to pump freon and oil into the system. Atmosphere humidity has gotten into the system from being apart, it will rust your compressor and in a year or so it will seize, and when your AC kicks on the belt will slip on the compressor pulley and you'll eat belts.

Other people may have done it and been fine but I got one year out of the AC on my dodge 2500 before the above happened. Had to buy a non-AC belt to run the bypass belt route.

Edited by JoeH
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1 hour ago, JoeH said:

You're supposed to put an AC vacuum machine on the system first, and use the same machine to pump freon and oil into the system. Atmosphere humidity has gotten into the system from being apart, it will rust your compressor and in a year or so it will seize, and when your AC kicks on the belt will slip on the compressor pulley and you'll eat belts.

Other people may have done it and been fine but I got one year out of the AC on my dodge 2500 before the above happened. Had to buy a non-AC belt to run the bypass belt route.

My A/C has been out for year due to a leak at the expansion Valve it’s just now that I’m fixing the issue since it’s really hot this year. Does the vacuum still matter since the system has been empty and not used? 

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Yes the vacuum sucks EVERYTHING out. Humidity, freon, oil... It puts a vacuum on the system for a half hour or something. Then the tech switches it over to fill it up.  When I had my car AC fixed 2 years ago the compressor was worn out, wasn't effective at moving the freon, even though it had a full charge.

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21 hours ago, JoeH said:

Yes the vacuum sucks EVERYTHING out. Humidity, freon, oil... It puts a vacuum on the system for a half hour or something. Then the tech switches it over to fill it up.  When I had my car AC fixed 2 years ago the compressor was worn out, wasn't effective at moving the freon, even though it had a full charge.

What #PAG OIL should I use 46 100 or 150? 

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I like 100 as it's a good medium viscosity oil. Yes, put a capsule of dye into the system. Replace all "O" rings you have taken apart and it's wouldn't be a bad idea to renew the seal a the lineset where it attaches to the compressor and receiver/dryer assemblies too. These sealing rings wear/age over time.

If the  system has been setting idle for an extended time I would replace the drier assembly too. That is the black cannister looking thing in the system under the hood. The evaporator core in the dash would be quite easy to remove to physically clean it with the system dumped and this would greatly help your comfort level once the system is back operational.

I would dump two ounces of PAG oil into the receiver/drier's inlet, button the system up, pull a vacuum on the system allowing it to dwell for an hour, (or more) to thoroughly evacuate any moisture present, then pressurize the system to 50psi with nitrogen administered with your service manifold set. Allow this charge to dwell in the system for an hour and check for any leakdown of pressure to ensure no leaks. If good, evacuate the system again with your vacuum pump and charge according to a vapor pressure charge reflecting the ambient temperature and the refrigerant you are using. System temperatures and pressures change with ambient temperature but ensure you have good airflow over the condenser coil in front of the radiator. A box, or tubeaxial fan is what I use and allow that system to operate in excess of 1/2 hour after you think it's good for stabilization. I hate "comebacks" because I got in a hurry.....

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Posted (edited)

After my first debacle doing my own AC I just pay the professionals to do it. Took me 2 days (not full work days, but I had to learn what I was doing) and $400+ in parts to do it myself the first time, then it cost me $700 a year later to have my local shop do it.  AC is something I don't care to get good at bc I don't have the tools.  Not worth a seized AC compressor at 2am in a snow storm when I could be making $85+/hour. Mine seized, clutch and all. So it wasn't like I could pull the relay to disengage the compressor clutch. 

Edited by JoeH

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Posted (edited)

Pulling a vacuum (should be about 25+ inches) and letting it sit for 15 minutes under vacuum will also give a good check for any leaks. If the Vacuum drops go tighten everything again and check with a few drops on oil. Alot easier and cheaper to check under vacuum than a 134 leak.

Edited by 41chevy

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Vacuum should be 29.992" to ensure efficient "boiloff" of any contained refrigerant/moisture within the remaining lubricant in the system. Close enough to 30" which is not attainable on the planet.

 

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Should I just replace the receiver drier? 

On 7/13/2019 at 6:26 PM, Rob said:

I like 100 as it's a good medium viscosity oil. Yes, put a capsule of dye into the system. Replace all "O" rings you have taken apart and it's wouldn't be a bad idea to renew the seal a the lineset where it attaches to the compressor and receiver/dryer assemblies too. These sealing rings wear/age over time.

If the  system has been setting idle for an extended time I would replace the drier assembly too. That is the black cannister looking thing in the system under the hood. The evaporator core in the dash would be quite easy to remove to physically clean it with the system dumped and this would greatly help your comfort level once the system is back operational.

I would dump two ounces of PAG oil into the receiver/drier's inlet, button the system up, pull a vacuum on the system allowing it to dwell for an hour, (or more) to thoroughly evacuate any moisture present, then pressurize the system to 50psi with nitrogen administered with your service manifold set. Allow this charge to dwell in the system for an hour and check for any leakdown of pressure to ensure no leaks. If good, evacuate the system again with your vacuum pump and charge according to a vapor pressure charge reflecting the ambient temperature and the refrigerant you are using. System temperatures and pressures change with ambient temperature but ensure you have good airflow over the condenser coil in front of the radiator. A box, or tubeaxial fan is what I use and allow that system to operate in excess of 1/2 hour after you think it's good for stabilization. I hate "comebacks" because I got in a hurry.....

 

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In my opinion, yes. Most definitely.

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On 7/14/2019 at 9:21 PM, Rob said:

In my opinion, yes. Most definitely.

Rob I put the new expansion Valve on and replaced the receiver drier with a new one. I’m now performing vacuum but the readings I’m getting make me worried please take a look... I purchased manifold gauges and vacuum pump from harbor freight and I put the gauges on turn the pump on I see a mist coming from the pump is that normal? 

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Also when performing a vacuum I open both sides of the gauge correct? 

image.jpg

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Yes; that’s normal, moisture; you just want to make sure you close the high side before filling. You can just pump it down on low side only. I always pump it down an close it off on gauges & check for 30 minutes & then I back off on the connector to the schraider valves. (Might have spelled wrong) because they are bad about leaking also.

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For CH 3LBs or 4 12 Ounce Cans of Freon should be good with 9 fl ounces of PAG 100 Oil should be enough for CH daycare/ dump truck? 

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