AC heat questions 300SD 1979

Mercedes Benz Forum Mercedes Classifieds Photo Gallery Member List Search Mercedes History Sponsors Contact
Mercedes Benz News Calendars Forum FAQ Mercedes Recalls TSBs Timeslips Register Login

AC heat questions 300SD 1979

Printable Version

Mercedes Forums >> Mercedes Benz Models >> Diesel Discussions >> AC heat questions 300SD 1979

Page: [1]

Message

<< Older Topic Newer Topic >>

AC heat questions 300SD 1979 - 5/27/2008 4:13:10 PM

Dieseladdict

Posts: 12
Joined: 5/20/2008
Status: offline

Thanks again for all the great responses to my WVO question.
Its getting pretty hot here in Mississippi and I'm thinking about spending some tax return money to get the old AC going in my '79 300SD. I heard there was an aftermarket replacement for the servo but can't seem to locate in with the search function. Can anyone help me out here?

Post #: 1

RE: AC heat questions 300SD 1979 - 5/28/2008 5:46:47 AM

ForcedInduction

Posts: 864
Joined: 5/20/2006
From: Federal Heights, Colorado
Status: offline

$639 to replace the EVIL servo.
http://www.performanceproducts4benz.com/productpage.aspx?pid=109850&cid=3&sid=383

Don't settle for an R134a conversion. Locate some R12 (eBay), fix every possible leak and stick with R12. R134a dos not cool as well as R12 and the stock A/C condenser does not have enough extra surface area to make up for that.

< Message edited by ForcedInduction -- 5/28/2008 5:47:45 AM >

_____________________________

1980 240D 3.0VNT 222K Miles. OM617.95, GT2256V VNT turbo, 4-speed manual, 3.46 diff, 15mm rear swaybar, ALDA removed, no EGR and Amsoil by-pass oil filter. Currently 107HP and 195lb/ft of torque at the wheels.

www.youtube.com/Turbo617

(in reply to Dieseladdict)

Post #: 2

RE: AC heat questions 300SD 1979 - 5/29/2008 7:32:49 AM

Dieseladdict

Posts: 12
Joined: 5/20/2008
Status: offline

thanks. thats what I was looking for.
Will installing that make the dash control work again? At the moment only the blower functions when one pushes the top button.

< Message edited by Dieseladdict -- 5/29/2008 7:35:16 AM >

(in reply to ForcedInduction)

Post #: 3

RE: AC heat questions 300SD 1979 - 5/29/2008 11:26:36 AM

Drrty240D

Posts: 154
Joined: 7/30/2006
Status: online

I wholeheartedly agree! R134a is bad news for A/C systems designed around R12. Whatever you do *do not* buy one of those Interdynamics retrofit systems and convert your A/C to R134a. Big mistake.

There are some very good R12 compatible refrigerants that do not require you to retrofit (or even change the existing oil in) your R12 system. A company called EnviroSafe makes a good R12 compatible refrigerant and if memory serves there is another good one called Autofrost. These are not R134a refrigerants and may be used alone or in conjunction with R12 freon.

Unless you are a licensed mechanic it is illegal for you to handle R12 freon, so buying from eBay will put you at risk of breaking the law.

< Message edited by Drrty240D -- 5/29/2008 11:29:13 AM >

(in reply to Dieseladdict)

Post #: 4

RE: AC heat questions 300SD 1979 - 5/29/2008 11:32:26 AM

Drrty240D

Posts: 154
Joined: 7/30/2006
Status: online

Yes. If your system is leak free and is working properly your dash controls should work again once the system is pressurized. There is a pressure cut-off that won't allow the compressor to run when the system is not charged with refrigerant.

(in reply to Dieseladdict)

Post #: 5

RE: AC heat questions 300SD 1979 - 5/29/2008 2:13:43 PM

ForcedInduction

Posts: 864
Joined: 5/20/2006
From: Federal Heights, Colorado
Status: offline

quote:

ORIGINAL: Drrty240D

Unless you are a licensed mechanic it is illegal for you to handle R12 freon, so buying from eBay will put you at risk of breaking the law.

All you have to do is be certified. It costs $15 and its an open book test that is stupidly simple to pass with common sence.
http://www.ase.com/Content/NavigationMenu/ASE_Resource_Center1/About_ASE1/Refrigerant_Recovery_and_Recycling_Online_Quiz/Refrigerant_Recovery_and_Recycling_Online_Quiz.htm

_____________________________

1980 240D 3.0VNT 222K Miles. OM617.95, GT2256V VNT turbo, 4-speed manual, 3.46 diff, 15mm rear swaybar, ALDA removed, no EGR and Amsoil by-pass oil filter. Currently 107HP and 195lb/ft of torque at the wheels.

www.youtube.com/Turbo617

(in reply to Drrty240D)

Post #: 6

RE: AC heat questions 300SD 1979 - 5/29/2008 2:13:48 PM

Dieseladdict

Posts: 12
Joined: 5/20/2008
Status: offline

thanks for the helpful tip. When you say leaks, are you referring to vacumn leaks? Should I just go through and replace all old vacumn hoses and fittings?

(in reply to Drrty240D)

Post #: 7

RE: AC heat questions 300SD 1979 - 5/29/2008 5:36:31 PM

Drrty240D

Posts: 154
Joined: 7/30/2006
Status: online

I'm referring to refrigerant line leaks. You have one, ostensibly, or the refrigerant level would be 100% and the A/C system would be working. You may wish to consult a professional mechanic if you are not sure about what to do. You can cost yourself a lot of money in this area by making mistakes.

Doesn't sound like you should be taking the freon recovery & recycling test for $15 -- put that toward the mechanic's bill and get your car fixed by a good, reliable mechanic who knows M-B.

(in reply to Dieseladdict)

Post #: 8