A/C used to but doesn't keep cold anymore - Mercedes-Benz Forum

LinkBack Thread Tools Display Modes
post #1 of 3 (permalink) Old 03-11-2010, 02:19 PM Thread Starter
BenzWorld Junior Member
sierra1194's Avatar
Date registered: Mar 2004
Vehicle: 1981 300D, 1967 VW BUG
Location: SoCal
Posts: 24
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
A/C used to but doesn't keep cold anymore

I live in So Caliifornia and need my A/C. It used to be really cold but nada. I was advised and had it converted from the old system? to R134A, replacing a receiver/drier, pressure switch and it was charged up with new refrigerant.

1) Air blows, but it isn't cold at all as if the refrigerant leaked away. My current mechanic charged up the refrigerant for me and it was fine when I drove away. Come summer, nada, no cold air at all. Is a compressor leaking or needs to be replaced? Loose lines somewhere? Other possibilities?

How should I go about checking this out.

2) No air comes out of the center vents either.

sierra1194 is offline  
Sponsored Links
post #2 of 3 (permalink) Old 03-11-2010, 03:08 PM
BenzWorld Junior Member
Date registered: Sep 2009
Location: Santa Barbara, Ca
Posts: 6
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
If you don't have pressure gauges then you'll need to take it back to the mechanic that converted it. Or if you don't like him anyone that can work on A/C.

You'd need the gauges to diagnose the system, the center vents not blowing air is another, separate, problem.

Good luck!
MechSB is offline  
post #3 of 3 (permalink) Old 03-11-2010, 07:44 PM
BenzWorld Member
Date registered: Apr 2008
Posts: 86
Mentioned: 1 Post(s)
Quoted: 2 Post(s)
You're probably going to continue to have problems with this setup. I've tried the conversion from R12 to R134 on another vehicle (non MB) and ended up having to replace everything. First the R134 requires a significantly higher pressure to cool properly, and if you have an old tired York compressor, it may not cut the mustard. If you don't want to spring for R12 there are several replacements available for this freon. I used Freeze 12 and it works more like R12, but still not quite as cold. Let us know what comes of this. I know you need real cooling down there. On my Benz I also put in all electric fans, as with the A/C on I used to heat up in traffic before. I am using a 16 in. in front of the radiator (replacing the stock one) and use a thermostatically controlled 14 in. in place of the stock water pump driven clutch fan. I've had this setup for almost a year now and so far it seems to be working quite well. I've also got them set up so all fans are running anytime the A/C is on, in addition to having the front one come on with the 100 C switch on the engine.
mbbuff is offline  
Sponsored Links

  Mercedes-Benz Forum > General Mercedes-Benz Forums > Vintage Mercedes-Benz

Quick Reply

Register Now

In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


  • Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
    Thread Tools
    Show Printable Version Show Printable Version
    Email this Page Email this Page
    Display Modes
    Linear Mode Linear Mode

    Similar Threads
    Topic Author Forum Replies Last Post
    Cold, COLD starts. Emergency cold start tips? n23ova W123 E,CE,D,CD,TD,TE Class 24 11-09-2011 05:27 PM
    frozen toes, lower vent blows cold cold air when heat is on?? mbnz230 W202 C-Class 3 05-31-2011 02:17 PM
    Justice is a dish sometimes served up cold or at least with a side of cold metal tool Jakarta Expat Off-Topic 6 01-15-2008 10:54 AM
    AC will not blow cold air anymore moose300d W163 M-Class 5 05-14-2006 08:07 PM
    I just cant take it anymore!! 300Diesel W123 E,CE,D,CD,TD,TE Class 3 10-18-2005 06:31 PM

    Posting Rules  
    You may post new threads
    You may 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 Off
    Trackbacks are On
    Pingbacks are On
    Refbacks are On


    Title goes here

    video goes here
    description goes here. Read Full Story
    For the best viewing experience please update your browser to Google Chrome