changing ac compressor

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pina4greg
E Class
Posts: 52
Joined: Tue 09 May, 2017 11:53 pm
Model you own: w140
Region: Western Australia
Location: Eglinton

changing ac compressor

Post by pina4greg » Wed 27 Dec, 2017 5:35 pm

I am going to attempt to change my ac compressor on my 1992 w140 300se.
Can I just undo the connections or is it pressurized and need special tools? also the compressor I am getting from the States comes with no oil. Do I need to fill it before install or can I install and then get it filled and gassed later as long as I don't turn it on. In other words can I just connect it and then drive it to get it gassed etc???

New tried this sort before so sorry if its a dumb question.....

Cheers

Greg
1992 W140 300se

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Tony From West Oz
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Posts: 3206
Joined: Mon 20 Jun, 2005 9:04 pm
Model you own: w202
Location: Bedfordale WA

Re: changing ac compressor

Post by Tony From West Oz » Wed 27 Dec, 2017 6:41 pm

When I changed mine I didn't turn the A/C on until it was gassed up.
If it is not filled with oil, then don't run it until lubed and gassed.
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (SOLD)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

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Ivanerrol
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Posts: 5792
Joined: Sat 12 May, 2007 2:21 pm
Model you own: w204
Location: Melbourne

Re: changing ac compressor

Post by Ivanerrol » Wed 27 Dec, 2017 7:44 pm

There will be a schrader valve on the high side piping.
Just give the little pin in the valve a gentle push - if there's any gas in there you will know.

If there is gas in there, go down to your local AC fill-up place and have all the current gas vacuumed out. They'll vaccum out the ester oil as well.
When it comes to fill up they will add oil and a trace colour (colour to detect leaks).
When you have the system apart, get all the old seals and take them to your AC guy. get new seals of him - he may charge you nothing for these as you will go back to get the gas reinstalled. There will be two seals on the compressor and one each on the high and low pressure lines.
You should be renewing the drier - the new one should comes with seals.

I remove the high pressure hose pipe first when the car is sitting on the ground. In your case the drier hoses as well.
Remove the serpentine belt. This may require removing the fan shroud which in turn may require removal of the fan blades.
Then lift the car and remove the engine cover.
Your compressor should be a four bolt model - maybe a three bolt. There may not be enough room to remove the bolts from the compressor. undo the bolts and let them loose.
The compressor should come out. The compressor on my W202 came out from the bottom. The compressor on the W210 came out the top.
Reinstall is reversal of the process.

When installing the seals make sure you lube them with a little bit of ester oil.
W211 - E240
W204 - C280
Departed
W202 - C200, C180, C180
W126 - 380SE , 380SE (Ex SA Import), 560SEL
W124 - 300e, 260e (ex Japan)
W111 220s (Indonesia) 4 speed manual column shift
W123 230
W116 450SEL
W140 420SEL
W210 E240, E240
W209 CLK 240
W201 190e 2.6 (ex U.K.)

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pina4greg
E Class
Posts: 52
Joined: Tue 09 May, 2017 11:53 pm
Model you own: w140
Region: Western Australia
Location: Eglinton

Re: changing ac compressor

Post by pina4greg » Wed 27 Dec, 2017 8:07 pm

Thanks guys, I did supply my vin to Pelican Parts to make sure I got the correct compressor so "should" fit...
Will follow the advice. So the car is safe to drive with the new compressor installed without oil or refrigerant in it as long as I dont turn the ac on?
1992 W140 300se

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Ivanerrol
Mercedes Demigod
Posts: 5792
Joined: Sat 12 May, 2007 2:21 pm
Model you own: w204
Location: Melbourne

Re: changing ac compressor

Post by Ivanerrol » Wed 27 Dec, 2017 9:51 pm

The drier has a little pressure switch on the top. (you will need to relocate this switch to your new drier).
If there is no gas in the system or too little gas the detector switch on the drier wont let the electric clutch on the compressor to activate.
You can push the EC button or AC button on the controller until the cows come home - but the compressor will not start.

Plenty of cars running around with no gas in the AC system.
W211 - E240
W204 - C280
Departed
W202 - C200, C180, C180
W126 - 380SE , 380SE (Ex SA Import), 560SEL
W124 - 300e, 260e (ex Japan)
W111 220s (Indonesia) 4 speed manual column shift
W123 230
W116 450SEL
W140 420SEL
W210 E240, E240
W209 CLK 240
W201 190e 2.6 (ex U.K.)

User avatar
pina4greg
E Class
Posts: 52
Joined: Tue 09 May, 2017 11:53 pm
Model you own: w140
Region: Western Australia
Location: Eglinton

Re: changing ac compressor

Post by pina4greg » Fri 29 Dec, 2017 6:34 pm

I will need to jack up the front of the car to access the compressor and will need jack stands.

Where is the best place to place them under the car?

Obviously will be using the jack position on the car to lift it.

Cheers

Greg
1992 W140 300se

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Tony From West Oz
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Posts: 3206
Joined: Mon 20 Jun, 2005 9:04 pm
Model you own: w202
Location: Bedfordale WA

Re: changing ac compressor

Post by Tony From West Oz » Sat 30 Dec, 2017 9:39 pm

Use the supplied jack to lift the car using the jacking holes in the rocker panels. Add car stands under the body just inboard of the jacking points. Usually there will be a rubber block on the rail at that point.
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (SOLD)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

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