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AC won't hold vacuum [message #261849]

Sun, 14 September 2014 12:43

Keith V

Messages: 2337
Registered: March 2008
Location: Mounds View,MN

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So I replaced the high pressure hose from the compressor to the condenser and the accumulator after the hose hit the pulley.

now when I pull a vacuum it pulls down fine but it wont hold. after about 4 hours its lost some vacuum.
the place that redid the hose welded on some new connectors does anyone think the hose could be bad?

Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com

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Re: AC won't hold vacuum [message #261863 is a reply to message #261849]

Sun, 14 September 2014 14:10

roy1

Messages: 2126
Registered: July 2004
Location: Minden nevada

Karma: 6

Senior Member

It is possible the new hose or o rings are leaking it is also possible your gage hoses are leaking can you pressurize it to 30 or 40 lbs with co2 ,nitrogen or refrigerant and use soap bubbles at all the hose and gage set fittings or connections?

Roy Keen Minden,NV 76 X Glenbrook

[Updated on: Sun, 14 September 2014 14:10]

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Re: [GMCnet] AC won't hold vacuum [message #261880 is a reply to message #261849]

Sun, 14 September 2014 16:54

emerystora

Messages: 4442
Registered: January 2004

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Pressurize the system from a nitrogen bottle (or use 50-100 psi of clean air).
Then you can check everything with some soap solution (gas leak detector will work well). When you see bubbles you have found the leak.

Emery Stora
On Sep 14, 2014, at 11:43 AM, Keith V wrote:

> So I replaced the high pressure hose from the compressor to the condenser and the accumulator after the hose hit the pulley.
>
> now when I pull a vacuum it pulls down fine but it wont hold. after about 4 hours its lost some vacuum.
> the place that redid the hose welded on some new connectors does anyone think the hose could be bad?
>
> --
> Keith
> 69 Vette
> 29 Dodge
> 75 Royale GMC
> Mounds View. MN
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> GMCnet mailing list
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Re: [GMCnet] AC won't hold vacuum [message #261883 is a reply to message #261880]

Sun, 14 September 2014 17:55

Keith V

Messages: 2337
Registered: March 2008
Location: Mounds View,MN

Karma: 0

Senior Member

emerystora wrote on Sun, 14 September 2014 16:54

Pressurize the system from a nitrogen bottle (or use 50-100 psi of clean air).
Then you can check everything with some soap solution (gas leak detector will work well). When you see bubbles you have found the leak.

Emery Stora
On Sep 14, 2014, at 11:43 AM, Keith V wrote:

I'll give it a try, it lost about 5 in hg in 2 hours, so it's not a huge leak.
Frustrating though

Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com

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Re: [GMCnet] AC won't hold vacuum [message #261896 is a reply to message #261883]

Sun, 14 September 2014 19:50

Bullitthead

Messages: 1411
Registered: November 2013

Karma: 5

Senior Member

It may be the new shaft seal on the pump. I've had those leak vacuum until they get worn in. Rotate the pump by hand when you have vacuum on the system and see if leaks up quickly when you rotate it slowly.

Terry Kelpien ASE Master Technician 73 Glacier 260 Smithfield, Va.

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Re: [GMCnet] AC won't hold vacuum [message #261901 is a reply to message #261896]

Sun, 14 September 2014 20:42

Keith V

Messages: 2337
Registered: March 2008
Location: Mounds View,MN

Karma: 0

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Bullitthead wrote on Sun, 14 September 2014 19:50

It may be the new shaft seal on the pump. I've had those leak vacuum until they get worn in. Rotate the pump by hand when you have vacuum on the system and see if leaks up quickly when you rotate it slowly.

I should have mentioned it held vacuum till I replaced the hose.
It really seems like a bad hose.
The other thing is I didn't replace the orings onthe compressor to the hose.. maybe thats it

Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com

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Re: [GMCnet] AC won't hold vacuum [message #261902 is a reply to message #261896]

Sun, 14 September 2014 20:48

Keith V

Messages: 2337
Registered: March 2008
Location: Mounds View,MN

Karma: 0

Senior Member

Bullitthead wrote on Sun, 14 September 2014 19:50

It may be the new shaft seal on the pump. I've had those leak vacuum until they get worn in. Rotate the pump by hand when you have vacuum on the system and see if leaks up quickly when you rotate it slowly.

Oh and I didn't notice it leak faster when I rotated it

Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com

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Re: [GMCnet] AC won't hold vacuum [message #261916 is a reply to message #261902]

Sun, 14 September 2014 22:09

Bullitthead

Messages: 1411
Registered: November 2013

Karma: 5

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10-4 on the o-rings, that has gotten me before when the used ones were only used once and looked just fine. On the other hand, the o-rings on the FUEL connection right behind the intake on the C2500 I'm rescuing were all cut up and trashed out but they weren't leaking!
I replaced them anyway. Output o-rings on the Sanden compressor do not like to be used more than once for some reason.

Terry Kelpien ASE Master Technician 73 Glacier 260 Smithfield, Va.

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Re: [GMCnet] AC won't hold vacuum [message #262307 is a reply to message #261916]

Fri, 19 September 2014 09:02

Keith V

Messages: 2337
Registered: March 2008
Location: Mounds View,MN

Karma: 0

Senior Member

Bullitthead wrote on Sun, 14 September 2014 22:09

10-4 on the o-rings, that has gotten me before when the used ones were only used once and looked just fine. On the other hand, the o-rings on the FUEL connection right behind the intake on the C2500 I'm rescuing were all cut up and trashed out but they weren't leaking!
I replaced them anyway. Output o-rings on the Sanden compressor do not like to be used more than once for some reason.

I think I found my leak.
in our last episode we saw the vacuum would leak down over night, all the way to zero.

Last night after the coach had been sitting since saturday, I connected my gauges.. still at 10" of vacuum!
This is after letting it leak on sat for quite a while disconnecting and re connecting the gauges. So I think it's the low side gauge connector.

To test this I used compressed air to pressurize the system and I could HEAR air leaking from the low side gauge connector!
Soap testing showed no leaks at 150 psi.
I think it's time to charge the bad boy just in time for winter Razz

QUESTION.
Where does a guy get the huge O-Rings for the back of the compressor? NO ONE carries them
I assume an AC shop or Jim KI ( of course )

Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com

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Re: [GMCnet] AC won't hold vacuum [message #262314 is a reply to message #262307]

Fri, 19 September 2014 10:55

roy1

Messages: 2126
Registered: July 2004
Location: Minden nevada

Karma: 6

Senior Member

Keith V wrote on Fri, 19 September 2014 07:02

Bullitthead wrote on Sun, 14 September 2014 22:09
10-4 on the o-rings, that has gotten me before when the used ones were only used once and looked just fine. On the other hand, the o-rings on the FUEL connection right behind the intake on the C2500 I'm rescuing were all cut up and trashed out but they weren't leaking!
I replaced them anyway. Output o-rings on the Sanden compressor do not like to be used more than once for some reason.

I think I found my leak.
in our last episode we saw the vacuum would leak down over night, all the way to zero.

Last night after the coach had been sitting since saturday, I connected my gauges.. still at 10" of vacuum!
This is after letting it leak on sat for quite a while disconnecting and re connecting the gauges. So I think it's the low side gauge connector.

To test this I used compressed air to pressurize the system and I could HEAR air leaking from the low side gauge connector!
Soap testing showed no leaks at 150 psi.
I think it's time to charge the bad boy just in time for winter

QUESTION.
Where does a guy get the huge O-Rings for the back of the compressor? NO ONE carries them
I assume an AC shop or Jim KI ( of course

That is a common leak my 4 sets of gauges leak at some point mostly the rubber o rings in the hoses. Did you check a hydrolic hose shop for the o ring?

Roy Keen Minden,NV 76 X Glenbrook

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Re: [GMCnet] AC won't hold vacuum [message #262315 is a reply to message #262307]

Fri, 19 September 2014 11:09

roy1

Messages: 2126
Registered: July 2004
Location: Minden nevada

Karma: 6

Senior Member

If you pressurized the system with shop air rather then co2 or nitrogen you might want to keep the vacuum pump on it for a bit moisture in the system is not your friend.

Roy Keen Minden,NV 76 X Glenbrook

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Re: [GMCnet] AC won't hold vacuum [message #262318 is a reply to message #262315]

Fri, 19 September 2014 12:38

Keith V

Messages: 2337
Registered: March 2008
Location: Mounds View,MN

Karma: 0

Senior Member

roy1 wrote on Fri, 19 September 2014 11:09

If you pressurized the system with shop air rather then co2 or nitrogen you might want to keep the vacuum pump on it for a bit moisture in the system is not your friend.

Oh yes, I'll rum the pump for quite a bit even though I did have a desiccant on the line

Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com

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