AC compressor

[Ivanerrol]

My W202 AC compressor was leaking from the front seal and one of the pipe connections on the rear.
Had another compressor so I decided to change it out myself.
Rather than screw around I took it to a AC specialist to suck the old remaining gas out and vacuum out the system. After I changed the compressor I would take to back to the specialist to regas the system. Ended up getting the specialist to do the whole job.
Here's some info.

My 1996 W202 has the older style engine and injection setup with the dreaded wiring issue however has a bunch of '97 update parts in it. One of them being the AC heating system. I bought a compressor for the older style i.e. a 4 bolt compressor - it didn't fit. My car has the later 3 bolt compressor. I had to chase up the later model compressor. The first one I obtained had a seized compressor spindle. Take care when buying used compressors make sure the belt pulley spins with out any noises and the compressor clutch spins.

AC specialist told me that there was too much green marker die in the system. Doesn't do the system any good.

A friend of mine - Parts dealer - has just come back from buying up parts in the middle east. Anecdotal reports from Dubai are that Hy Chill is causing premature compressor failure. This is anecdotal and not substantiated.

The clutch mechanism and fan pulley on the compressor is a replacement item easily obtained. You can do this replacement while the compressor is still gassed and in the car. The front seal on the compressor change is not a hard job but requires the evacuation of the gas.

[Giles]

Good news in the end.

My AC wasn't blowing cold in my W140 and the compressor wouldn't activate. If you know anything of the W140 the first items of many issues they have is the leaking evaporator.

Interestingly enough it would hold pressure once regassed at my local stealership and did all weekend. The other odds jobs were completed on the Monday, fortunately the head mechanic had returned from holidays and knew that the car had to be diagnosed and told that it had be regassed. Apparently the compressor shuts down with low gas and doesn't kick in until told it' be regassed.

Makes me wonder how many non-MB AC shops would know this.

Two weeks later the AC works like a treat, especially in the hot spell we are having in WA at the moment.

Giles

[Ivanerrol]

Hi Giles,

Have you determined how the gas was low in the first place?

My compressor would only leak gas when it was in operation. i.e. when the switch settings on the console were set to a temperature it would actually engage the clutch.

[Giles]

Hi Giles,

Have you determined how the gas was low in the first place?

My compressor would only leak gas when it was in operation. i.e. when the switch settings on the console were set to a temperature it would actually engage the clutch.

No idea of how low the gas was. We extracted what was left and refilled. I couldn't get the compressor to engage even with pulling the fuse. I thought about applying 12V direct but the problem was solved prior.

I found a PDF on AC faults, but didn't need to go through them. Just as well, it's a long list for a W140.

It performed so well today, third day of high 30C.

Giles

[Ivanerrol]

Stripped down compressor.
Have a look

Compressor-01.jpg

Compressor-03.jpg

Compressor-02.jpg

Compressor is cactus.
Bearing obviously gone wonky, compressor pistons spinning out of line and hitting side of compressor top casting, casting fractured = leak

[Giles]

Was the damage on the lower side of the casting?

I'm just wondering if the bearing had too much force applied by a belt that was too tight.

Giles

[Ivanerrol]

I pulled the front shaft seals and bearings out - the seals were shot.
The bearings don't look flash and the shaft is scored.
The pistons - some were good and loose in their chambers others were tight and probably on the verge of seizure.
I'd guess that the play in the shaft and bearings contributed to some of the pistons hitting the side of the compressor case.

Or I may have it arse backwards and the case had a casting defect and cracked and that this contributed to the distortion, the pistons hitting the case and causing the wear on the shaft.

Someone previously has changed the clutch and pulley. The pulley bearing is noiseless.

As an aside. The Garage Queen W210's AC gas has now leaked out. The marker die indicates it's leaking out of the seal on the high pressure connection on the compressor
Probably a case of not using the car much and not using the AC - seals dried out from lack of use and circulation of the lubricating oil. :boohoo:

[atomdude]

Hi

i just found out the may compressor is leaking on my W202 from the ac specialist. i don't where exactly, so
* how can i identify where the leak exactly
* how to repair it

Thanks

[Ivanerrol]

Hi
i just found out the may compressor is leaking on my W202 from the ac specialist. i don't where exactly, so
* how can i identify where the leak exactly
* how to repair it
Thanks

Does your specialist not know where the leak is?

If the leak is from the rear top seals then it's a rather simple replacement.
If the shaft seals are gone then the compressor must be removed from the car and the front and rear bearings and seals replaced - in fact if you actually do this you may as well have the compressor completely rebuilt.
Completely rebuilding the compressor by a specialist is not economical viable so you are left with sourcing a reconditioned unit from the states or buying a new one.
There are new replacements Denso compressors on fleabay at the moment ranging from $366.00 to $900.00

Buying a second hand unit from a wrecker is risky business.

[billybumps123]

Try hontoys Smithfield now

[pina4greg]

Is there a reliable mechanic for Mercedes in Perth?

[Tony From West Oz]

Try looking here: viewtopic.php?f=25&t=24355#p175082

[pina4greg]

Have been buying the odd part from Pelican parts in the USA. Seem to be pretty well priced. With the engine running on my W140 when you turn on the ac the engine stalls...... been told its probably a seized compressor. Does this sound correct. Part from Pelican parts is about $350

[dunky]

Also check out RockAuto also in Amercia. Have parts for most cars.

[Tony From West Oz]

Have been buying the odd part from Pelican parts in the USA. Seem to be pretty well priced. With the engine running on my W140 when you turn on the ac the engine stalls...... been told its probably a seized compressor. Does this sound correct. Part from Pelican parts is about $350

Does that price include freight and import duty / GST?
You can buy a brand new compressor for around $400 in Australia with local warranty.
I just replaced the compressor and dryer in my C250 (now sold) for $450 (I did the installation) and gassed up for $100 by an Auto Air Cond man I know.

[Ivanerrol]

If you want top buy one from overseas then do it Direct. Stealbay is now charging sellers GST on the selling price plus the fee. - (Gov't requirement).
There's Pelican. FCP, eeurparts, Autohauz Arizona etc.
Get their inclusive prices and compare.

You will need a new drier plus seals for the compressor plus the piping seals and potentially a new condenser.

Now here's the bad news.

W140's suffer from bad evaporators. They are a 20 hour replacement job for experienced mechanistic to change. Probably a week for the average DIYer

Buying a W140 with a non working AC is a real deal killer.
The evaporator and self closing door pumps on the W140 mar an excellent vehicle.

[pina4greg]

Look1ng at about $600 au for a new Denso compressor including shipping. priced one from a Denso distributor and was shocked to hear $1300. The even suggested going through a trade to get a bit of wholesale discount.

So Tony, if I get a compressor then need all the other stuff too? may be a long hot summer.....

[pina4greg]

Have been buying the odd part from Pelican parts in the USA. Seem to be pretty well priced. With the engine running on my W140 when you turn on the ac the engine stalls...... been told its probably a seized compressor. Does this sound correct. Part from Pelican parts is about $350

Does that price include freight and import duty / GST?
You can buy a brand new compressor for around $400 in Australia with local warranty.
I just replaced the compressor and dryer in my C250 (now sold) for $450 (I did the installation) and gassed up for $100 by an Auto Air Cond man I know.

Where did you source your purchase from.???

[Tony From West Oz]

Travel Supercool, 5 Harold St Dianella WA 92729778. I went there and there were a couple of possible Compressors for my C250. We found the one with the correct pipe connections. I went home and tried to put it on but found the pulley did not align with the belt. A quick phone call later and he was on his way to me to pick it up (3/4 hour each way). He took both compressors and swapped the old pulley onto the new compressor, after cleaning the inside of the pulley where the clutch works. Brought it back 4 hours later. He drove about 120km and took about 4 hours out of his day to keep his customer (me) happy.
I call that good service.

[pina4greg]

Sounds like a pretty good recommendation .....Mighht get them to look the system over?. Thanks for the info..

Greg

[Tony From West Oz]

Just be aware that they are a parts supplier, not a repair outfit.