Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 08-22-2008, 10:18 AM
JCSC2's Avatar
Registered User
 
Join Date: Jul 2006
Location: Nashville, TN
Posts: 209
Testing a/c for amount of R134

I have previously reported in threads about my a/c not working well in my 300SD. But today my employee/buddy has brought in an a/c gauge. It has levels indicated on it for the low and high side. How do I go about checking the amount of R134 in the system? Also how much does it hold? I apologize I did not search hard and it's probably be spoke of dozens of time. We are at work now. Thank-you.
Also for a recap my a/c sucks! It puts out on only moderately cold a/c if car is moving along at a good pace and not stopping. If you stop at a light or in stop and go traffic, the a/c puts out hot air. Also it makes a bad whistling noise when you stop or shut off a/c. Like it is releasing a lot of pressure. Also it sounds like the compressor(or something) is "ticking" while running. Stops when it is shut off. Any suggestions and ideas are greatly appreciated. The car was converted to R134 some years ago. When my Mom owned the car(been in family since 91) she had R134 added from time to time.

__________________
1985 Mercedes Benz 300SD, TMU
2015 Chrysler 200S
Reply With Quote
  #2  
Old 08-22-2008, 02:17 PM
dannym's Avatar
I'm not here
 
Join Date: Oct 2004
Location: Deltona, Florida
Posts: 2,360
Quote:
Originally Posted by JCSC2 View Post
I have previously reported in threads about my a/c not working well in my 300SD. But today my employee/buddy has brought in an a/c gauge. It has levels indicated on it for the low and high side. How do I go about checking the amount of R134 in the system? Also how much does it hold? I apologize I did not search hard and it's probably be spoke of dozens of time. We are at work now. Thank-you.
Also for a recap my a/c sucks! It puts out on only moderately cold a/c if car is moving along at a good pace and not stopping. If you stop at a light or in stop and go traffic, the a/c puts out hot air. Also it makes a bad whistling noise when you stop or shut off a/c. Like it is releasing a lot of pressure. Also it sounds like the compressor(or something) is "ticking" while running. Stops when it is shut off. Any suggestions and ideas are greatly appreciated. The car was converted to R134 some years ago. When my Mom owned the car(been in family since 91) she had R134 added from time to time.
The gauges don't have "level" indicators on it. It has pressure & temperature, which you left out of your message. We need to know the high side pressure, the low side pressure and the outside air temperature.

That said there is really no way to know exactly how much refrigerant is in there. There are 2 ways to find out.
1-Recover the refrigerant into a recycle container and weight it.
2-Flush out the system and replace with the proper amount of refrigerant & oil.

That last comment in bold scares me. When refrigerant leaks out, oil leaks out with it. Not only do you not know how much refrigerant is in there you don't know how much oil is in there either.
Get too low on the oil and your compressor WILL seize up.

Danny
__________________
1984 300SD Turbo Diesel 150,000 miles

OBK member #23

(\__/)
(='.'=) This is Bunny. Copy and paste bunny into your
(")_(") signature to help him gain world domination
Reply With Quote
  #3  
Old 08-22-2008, 02:21 PM
rrgrassi's Avatar
mmmmmm Diesel...
 
Join Date: Jun 2006
Location: Royse City Tx
Posts: 5,177
Yep, what danny said. Also lack of oil can mean black death (metal shavings) pumped through the system before the compressor seizes.
__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K
Reply With Quote
  #4  
Old 08-22-2008, 02:52 PM
JCSC2's Avatar
Registered User
 
Join Date: Jul 2006
Location: Nashville, TN
Posts: 209
Quote:
Originally Posted by dannym View Post
The gauges don't have "level" indicators on it. It has pressure & temperature, which you left out of your message. We need to know the high side pressure, the low side pressure and the outside air temperature.

That said there is really no way to know exactly how much refrigerant is in there. There are 2 ways to find out.
1-Recover the refrigerant into a recycle container and weight it.
2-Flush out the system and replace with the proper amount of refrigerant & oil.

That last comment in bold scares me. When refrigerant leaks out, oil leaks out with it. Not only do you not know how much refrigerant is in there you don't know how much oil is in there either.
Get too low on the oil and your compressor WILL seize up.

Danny
Hmmm, thanks for the heads up. I don't wanna make things worse, thats for sure. I didn't look at the level closely when I posted earlier. But it does say low, full, alert on it, along with numbers which I assume is the pressure. It's an odd looking gauge. Kinda like an old style tire pressure gauge. Never the less, I think it may be best to remove all the old
R134 out and put in new. I'm not the best informed when it comes to a/c. But I thought the oil was mixed up in the can with the R134? Please pardon my ignorance. What is the proper amount of oil and refrigerent for an 85 300SD? Actually since this is a newer style compressor it may be listed on it somewhere?

__________________
1985 Mercedes Benz 300SD, TMU
2015 Chrysler 200S
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 08:40 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page