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  #1  
Old   
randallbrink@mac.com
 
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Default Another Insult - 09-18-2009 , 09:31 PM






No sooner have I retrieved my 300D from the engine shop with
completely new everything, EXCEPT, I did not replace the A/C
Compressor, but did have it switched to the new R134A refrigerant.

Well, today, I was motoring down the freeway, when smoke began to
plume from behind, and POOF. A/C compressor seized!. The engine quit,
of course, and I had the car towed to the shop.

We'll see how much this will cost, for a new compressor and the labor
to install, etc.

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  #2  
Old   
trader4@optonline.net
 
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Default Re: Another Insult - 09-19-2009 , 07:35 AM






On Sep 18, 9:31*pm, "randallbr... (AT) mac (DOT) com" <randallbr... (AT) gmail (DOT) com>
wrote:
Quote:
No sooner have I retrieved my 300D from the engine shop with
completely new everything, EXCEPT, I did not replace the A/C
Compressor, but did have it switched to the new R134A refrigerant.

Well, today, I was motoring down the freeway, when smoke began to
plume from behind, and POOF. *A/C compressor seized!. The engine quit,
of course, and I had the car towed to the shop.

We'll see how much this will cost, for a new compressor and the labor
to install, etc.
I hope you had it towed to a shop other than the one that keeps
screwing everything up, ie all the problems you had after the engine
rebuild and how long it took them to figure it out. It's
suspicious the compressor failed right after the conversion.

I would have taken it someplace else where you could have gotten an
independent evaluation and might have found out they screwed that up
too by doing something like not putting oil in it, or not evacuating
and correctly refilling it, etc. If you took it back to the screw
ups, all they are gonna tell you is you need a new compressor because
it just went kaput on it's own and you're gonna pay for the whole
thing anyway.

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  #3  
Old   
randallbrink
 
Posts: n/a

Default Re: Another Insult - 09-19-2009 , 08:10 AM



On Sep 19, 4:35*am, trad... (AT) optonline (DOT) net wrote:
Quote:
On Sep 18, 9:31*pm, "randallbr... (AT) mac (DOT) com" <randallbr... (AT) gmail (DOT) com
wrote:

No sooner have I retrieved my 300D from the engine shop with
completely new everything, EXCEPT, I did not replace the A/C
Compressor, but did have it switched to the new R134A refrigerant.

Well, today, I was motoring down the freeway, when smoke began to
plume from behind, and POOF. *A/C compressor seized!. The engine quit,
of course, and I had the car towed to the shop.

We'll see how much this will cost, for a new compressor and the labor
to install, etc.

I hope you had it towed to a shop other than the one that keeps
screwing everything up, ie all the problems you had after the engine
rebuild and how long it took them to figure it out. * * It's
suspicious the compressor failed right after the conversion.

I would have taken it someplace else where you could have gotten an
independent evaluation and might have found out they screwed that up
too by doing something like not putting oil in it, or not evacuating
and correctly refilling it, etc. * *If you took it back to the screw
ups, all they are gonna tell you is you need a new compressor because
it just went kaput on it's own and you're gonna pay for the whole
thing anyway.
Your points are well taken, and bring up a question: What exactly does
cause a compressor to fail? You mentioned not properly evacuating it,
and oil.

I do know that the shop had to recharge the system several times, and
never seemed to get it to work properly after converting from R12 to
R134 refrigerant. Last week, when I picked the car up from the shop,
the mechanic said the air conditioning worked. It "worked" only to
the extent that the fan activated and blew air, but the air output was
the temperature of dog's breath. It has never "worked" like you would
expect an air conditioner to work, i.e., blowing cold air.

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  #4  
Old   
Wan-ning Tan
 
Posts: n/a

Default Re: Another Insult - 09-19-2009 , 10:01 AM



Definitely time to change the shop. AC is not that difficult to work on
if the mechanic has the proper tools.

Possible causes of compressor seizure:
1. not enough oil
2. incorrect type of oil
3. debris

R12 uses mineral oil while R134a uses ester or PAG. R134a has different
characteristic and cannot circulate mineral oil. Without adequate
lubrication, the compressor will grind to a halt quickly. Sometimes the
failing compressor creates debris and kills itself. Debris can also be
introduced by opening the system without proper capping (for example,
during the engine replacement).

AC does not need to be opened (even for a conversion) unless a component
in its system is replaced. Now it needs to be opened to replace the
compressor. The receiver/drier should be replaced every time the system
is open. Existing oil should be drained as much as possible, especially
there was mineral oil in the past. The mineral oil itself will not hurt
the new system but it takes up volume while does not do any cooling.
Flush the system as much as possible. Connect all components then
evacuate with a vacuum pump for at least 30 minutes. Finally charge it
with correct amount of R134a and lubricant. The optimum R134a is about
85% of the volume of R12.

Remember that your AC system was designed for R12. R134a needs slightly
larger system to perform as good. Therefore, the cooling will never be
the same as new. However, my two conversions (84 190D and 87 300SDL)
work pretty well for me (in mid-Atlantic area, not the Arizona desert :-).


randallbrink wrote:
Quote:
On Sep 19, 4:35 am, trad... (AT) optonline (DOT) net wrote:

On Sep 18, 9:31 pm, "randallbr... (AT) mac (DOT) com" <randallbr... (AT) gmail (DOT) com
wrote:


No sooner have I retrieved my 300D from the engine shop with
completely new everything, EXCEPT, I did not replace the A/C
Compressor, but did have it switched to the new R134A refrigerant.

Well, today, I was motoring down the freeway, when smoke began to
plume from behind, and POOF. A/C compressor seized!. The engine quit,
of course, and I had the car towed to the shop.

We'll see how much this will cost, for a new compressor and the labor
to install, etc.

I hope you had it towed to a shop other than the one that keeps
screwing everything up, ie all the problems you had after the engine
rebuild and how long it took them to figure it out. It's
suspicious the compressor failed right after the conversion.

I would have taken it someplace else where you could have gotten an
independent evaluation and might have found out they screwed that up
too by doing something like not putting oil in it, or not evacuating
and correctly refilling it, etc. If you took it back to the screw
ups, all they are gonna tell you is you need a new compressor because
it just went kaput on it's own and you're gonna pay for the whole
thing anyway.


Your points are well taken, and bring up a question: What exactly does
cause a compressor to fail? You mentioned not properly evacuating it,
and oil.

I do know that the shop had to recharge the system several times, and
never seemed to get it to work properly after converting from R12 to
R134 refrigerant. Last week, when I picked the car up from the shop,
the mechanic said the air conditioning worked. It "worked" only to
the extent that the fan activated and blew air, but the air output was
the temperature of dog's breath. It has never "worked" like you would
expect an air conditioner to work, i.e., blowing cold air.

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  #5  
Old   
Tiger
 
Posts: n/a

Default Re: Another Insult - 09-19-2009 , 12:22 PM



Siezed AC compressor is almost always lack of oil... when you vacuum out the
refrigerant, you also take out the oil... With a fairly new machine, you
would know exactly how much oil you took out and reinject the same amount.

So whoever last worked on it, didn't make sure you have neough oil. Get
cheap compressor on ebay and have someone put it in... Don't let the shop
take you for a ride on the compressor... On youe car, it is probably about
$100 for a rebuilt compressor on ebay. I buy ebay compressor all the time...
zero problem.

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  #6  
Old   
Tiger
 
Posts: n/a

Default Re: Another Insult - 09-22-2009 , 02:26 PM



http://cgi.ebay.com/ebaymotors/1977-1985-Mercedes-300D-300SD-300TD-280-A-C-COMPRESSOR_W0QQcmdZViewItemQQ_trksidZp3286Q2ec0Q2e m14QQhashZitem48374ca439QQitemZ310165414969QQptZMo torsQ5fCarQ5fTruckQ5fPartsQ5fAccessories


I have bought two MB compressors from him.with optional drier... cheap too.

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  #7  
Old   
randallbrink
 
Posts: n/a

Default Re: Another Insult - 09-22-2009 , 03:31 PM



On Sep 19, 7:01*am, Wan-ning Tan <sun... (AT) erols (DOT) com> wrote:
Quote:
Definitely time to change the shop. *AC is not that difficult to work on
if the mechanic has the proper tools.

Possible causes of compressor seizure:
1. not enough oil
2. incorrect type of oil
3. debris

R12 uses mineral oil while R134a uses ester or PAG. *R134a has different
characteristic and cannot circulate mineral oil. *Without adequate
lubrication, the compressor will grind to a halt quickly. *Sometimes the
failing compressor creates debris and kills itself. *Debris can also be
introduced by opening the system without proper capping (for example,
during the engine replacement).

AC does not need to be opened (even for a conversion) unless a component
in its system is replaced. *Now it needs to be opened to replace the
compressor. *The receiver/drier should be replaced every time the system
is open. *Existing oil should be drained as much as possible, especially
there was mineral oil in the past. *The mineral oil itself will not hurt
the new system but it takes up volume while does not do any cooling.
Flush the system as much as possible. *Connect all components then
evacuate with a vacuum pump for at least 30 minutes. *Finally charge it
with correct amount of R134a and lubricant. *The optimum R134a is about
* 85% of the volume of R12.

Remember that your AC system was designed for R12. *R134a needs slightly
larger system to perform as good. *Therefore, the cooling will never be
the same as new. *However, my two conversions (84 190D and 87 300SDL)
work pretty well for me (in mid-Atlantic area, not the Arizona desert :-)..



randallbrink wrote:
On Sep 19, 4:35 am, trad... (AT) optonline (DOT) net wrote:

On Sep 18, 9:31 pm, "randallbr... (AT) mac (DOT) com" <randallbr... (AT) gmail (DOT) com
wrote:

No sooner have I retrieved my 300D from the engine shop with
completely new everything, EXCEPT, I did not replace the A/C
Compressor, but did have it switched to the new R134A refrigerant.

Well, today, I was motoring down the freeway, when smoke began to
plume from behind, and POOF. *A/C compressor seized!. The engine quit,
of course, and I had the car towed to the shop.

We'll see how much this will cost, for a new compressor and the labor
to install, etc.

I hope you had it towed to a shop other than the one that keeps
screwing everything up, ie all the problems you had after the engine
rebuild and how long it took them to figure it out. * * It's
suspicious the compressor failed right after the conversion.

I would have taken it someplace else where you could have gotten an
independent evaluation and might have found out they screwed that up
too by doing something like not putting oil in it, or not evacuating
and correctly refilling it, etc. * *If you took it back to the screw
ups, all they are gonna tell you is you need a new compressor because
it just went kaput on it's own and you're gonna pay for the whole
thing anyway.

Your points are well taken, and bring up a question: What exactly does
cause a compressor to fail? *You mentioned not properly evacuating it,
and oil.

I do know that the shop had to recharge the system several times, and
never seemed to get it to work properly after converting from R12 to
R134 refrigerant. Last week, when I picked the car up from the shop,
the mechanic said the air conditioning worked. *It "worked" only to
the extent that the fan activated and blew air, but the air output was
the temperature of dog's breath. *It has never "worked" like you would
expect an air conditioner to work, i.e., blowing cold air.
Thanks very much for this information and for th thorough description
of the system works. I am planning now to restore the system to R12,
given that the compressor and components will need replacement anyway.

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  #8  
Old   
randallbrink
 
Posts: n/a

Default Re: Another Insult - 09-22-2009 , 03:31 PM



On Sep 22, 11:26*am, "Tiger" <tiger0... (AT) hotmail (DOT) com> wrote:
Quote:
http://cgi.ebay.com/ebaymotors/1977-1985-Mercedes-300D-300SD-300TD-28...

I have bought two MB compressors from him.with optional drier... cheap too.
Tiger, Thanks. I'll pursue this, as I am now going to restore the
system to R12. I shold never have let the mechanic talk me into
converting to 134 in the first place.

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