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2001 eldorado,2008 DTS,2005 XLR, '96 eldo,'95 eldo,' 89 eldo,'78 eldo,'11CTS-V
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Discussion Starter #1
Have an interesting A/C problem on my '99 STS
Checking pressures, engine off, I get about 60#; suction side.
Start engine, and the low side starts dropping like normal, but after maybe 5 seconds the pressure starts climbing to 130#, and the high side is now over 300#. The clutch is now starting to smoke and I shut things down.
Any ideas?
 

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2001 eldorado,2008 DTS,2005 XLR, '96 eldo,'95 eldo,' 89 eldo,'78 eldo,'11CTS-V
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Discussion Starter #3
System worked fine last season; hasn't been touched since.
 

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White Diamond '03 DHS (with DTS floor shift)
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The only thing I can think of that would make the clutch smoke is the electromagnetic coil or the clutch plate slipping. The latter seems more likely if the compressor is beginning to seize, which might explain the high pressures.
 

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2001 eldorado,2008 DTS,2005 XLR, '96 eldo,'95 eldo,' 89 eldo,'78 eldo,'11CTS-V
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Discussion Starter #5
A smoking clutch would indicate a heavy load on the compressor, but a seizing of said compressor would not create such high pressures.
 

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White Diamond '03 DHS (with DTS floor shift)
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Maybe a bad clutch bearing? That could explain the smoking clutch, but not the high pressures. Maybe the two are unrelated.
 

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2001 eldorado,2008 DTS,2005 XLR, '96 eldo,'95 eldo,' 89 eldo,'78 eldo,'11CTS-V
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Discussion Starter #7
Another clue that I forgot was the condenser was so hot, it burned your hands. This is only after running for a couple of minutes.
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
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that IS a weird one Harry -
Checking pressures, engine off, I get about 60#; suction side
that is obviously the static pressure - and high side and low side should be the same -

after maybe 5 seconds the pressure starts climbing to 130#, and the high side is now over 300#.
..............the condenser was so hot, it burned your hands

my thought is WAY overcharged - AND it sounds like the compressor clutch was hot-wired to constantly run -
thus bypassing ALL the safety measures - freon temperature switch - high pressure switch - etc -

any AC related codes?
 

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2001 eldorado,2008 DTS,2005 XLR, '96 eldo,'95 eldo,' 89 eldo,'78 eldo,'11CTS-V
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Discussion Starter #9
Yes, the relay was bypassed. Overcharged is hard to explain or justify, but for shits and giggles, I'll bleed off some gas into a empty jug.
 

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99 Seville STS
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I had similar symptoms on my 73 Buick after having the system recharged and the guy who helped me had put in PAG oil by mistake which is a real bad combo with the mineral oil already in there.

It would cool for a while and then the belt started screaming as the compressor jammed.

Totally different cars and the Seville probably had PAG from the beginning I know, but it sounds like your system might be clogged up inside and that the compressor is struggling doings its job.
 

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2001 eldorado,2008 DTS,2005 XLR, '96 eldo,'95 eldo,' 89 eldo,'78 eldo,'11CTS-V
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Discussion Starter #11
Does the 30# drums of Freon have a one way valve in them?
I'm attempting to bleed off some Freon back into an empty drum, but it won't go. We're talking over 300# on the high side.
 

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92 Fleetwood 2dr cpe - FWD, 96 Seville SLS, 02 Seville
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Bleeding into a empty container will only drop the static pressure a bit as the system is only equalizing.

High on both sides is normally caused by overcharge. But a static pressure of 60# is normal for temps around 60-70.

Another common cause is the condensor is blocked and the Freon is unable to pickup heat from the interior.
 

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Discussion Starter #13
I wasn't clear on what I was doing.
I'm trying to dump some freon from a running system high side (350#) into a 30# fairly empty jug.
The condensor is so hot, you can't touch it.
I agree this sounds like an overcharged system, but it ran fine last year, and hasn't been touched since.
 

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99 Seville STS
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.Another common cause is the condensor is blocked and the Freon is unable to pickup heat from the interior.
The condensor is so hot, you can't touch it.
It sounds as you may have a clogged condenser, if you empty the system on cooling media and then disconnect the condensor at both ends and use compressed air to see if its blocked, if it is you have the answer there, then its either flush the old one or invest in a new.
This would explain why the problem came without the system being touched, as its then old dirt that has pilled up in there, they say new condensors are so impenetrable they can't be flushed and have to be replaced, not sure how new that applies to.
I'm not an AC expert, just sharing my thoughts about how I would move forward with it :)
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
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It sounds as you may have a clogged condenser, if you empty the system on cooling media and then disconnect the condensor at both ends and use compressed air to see if its blocked, if it is you have the answer there, then its either flush the old one or invest in a new.
This would explain why the problem came without the system being touched, as its then old dirt that has pilled up in there, they say new condensors are so impenetrable they can't be flushed and have to be replaced, not sure how new that applies to.
I'm not an AC expert, just sharing my thoughts about how I would move forward with it :)
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I thought about that too -
a clogged condenser could explain the high pressure between the compressor and condenser -
but - then I would expect an extremely LOW pressure on the suction side -
HOWEVER - the LOW side pressure is also extremely high -
 

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99 Seville STS
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=======================
I thought about that too -
a clogged condenser could explain the high pressure between the compressor and condenser -
but - then I would expect an extremely LOW pressure on the suction side -
HOWEVER - the LOW side pressure is also extremely high -
Totally agree,
The fact it was high on both sides got lost in translation by me…
 
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