The other commonly unknown fact is that the a/c fittings on the USA W123/126 vintage cars are SAE, not metric.

Thanks that is good to know. I would have gone at it with metric.

How do you put the Bordon tube back on the evaporator. It must be in contact with it to keep from freezing up??

Thanks
Robert
84 300SD

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84 300SD 84 300CD 85 300SD 85 300CD 98.5 Dodge 2500 Cummins 99 Dodge 2500 Cummins 90 Jeep for the sand Wilmington, NC

http://www.funnyyouasked.com/Mercedes/W126/ExpValve/removal_and_replacement_of_expan.htm


this is a pretty good write up.

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Eugene

10 E63 AMG
93 300te 4matic
07 BMW X3
14 Ford F-150 Fx2

i don't know what that tube is you refer to.
the expansion valve on mine is just above the throttle petal, yes a pain to work up there but not impossible. i used a 22mm on the big nuts and a 19 on the others i think. used a cresent to hold the valve and slightly position it when needed.
i removed it to do the proper flush of the evaporator. lots of gunk came out.
i don't have everything back together yet, but just work a little everyday.
i can see up there that if you take the instrument cluster out you could reach the valve but, yeah, the air tube would be in the way.
good luck, i hope you get it cooling soon.
r

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1985 300SD
1998 Jetta TDI
Previous: lots of diesel VW's, MB's, KW's, Pete, Freightliner


Walking isn't a lost art: one must, by some means, get to the garage.

http://www.brighthub.com/engineering/mechanical/articles/41946.aspx

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

I was under the impression that there was a Bordon tube going over to the evaporator. I am familiar with older systems like add on units for Ford and Gm before POA and VIR days. the expansion valves that I know of only have one inlet and one outlet with a controlled needle valve inside of it. I know about CCOT systems that are used today but the Mercedes is just a little different. It will be easier to deal with without the Bordon tube style of expansion valve.

Thanks a lot for all that helped.
Robert

Attached Thumbnails

 

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84 300SD 84 300CD 85 300SD 85 300CD 98.5 Dodge 2500 Cummins 99 Dodge 2500 Cummins 90 Jeep for the sand Wilmington, NC

unit, thus the tube monitors the outlet temp right there on the unit itself, thus no need to mount the tube.

This is a really good thing, because on those old units it was not uncommon for the bourdon tube to not be mounted correctly on the outlet in which case the valve would not regulate properly.
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Yes if the Bordon tube was not mounted correctly the AC would blow cold for a while and freeze up solid and then no more AC.

Thanks for your explanation.
One last question === Should I flush the evap??? If so which line do I use as in and can all the flush be blown out?? I do plan to flush the condenser and lines.
Thanks
Robert

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84 300SD 84 300CD 85 300SD 85 300CD 98.5 Dodge 2500 Cummins 99 Dodge 2500 Cummins 90 Jeep for the sand Wilmington, NC

Huh? Which is SAE? The threads or the head of the fitting? I removed the expansion valve from my 83 240D and the wrenches used were definitely metric and they fit perfectly.

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85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked