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 ShopForum > Technical Information and Support > Tech Help

LinkBack Thread Tools Display Modes
Old 03-22-2002, 06:16 PM
Registered User
Join Date: Mar 2002
Posts: 14
Expansion valve change on a 420 SEL

Good evening out there in Benzville! Has anyone changed an expansion valve on a 1990 420SEL? I'm leery of having to pull the two airbags if thats needed to complete the job. Can you access the valve from under the drivers side dash without having to pull the steering wheel? I assume if the evaporator is bad the whole dash has to be removed. I'm not picking up any refrigerant coming from the evap. drain but I am around the accel pedal area. If I get in there and it looks like the evap. is bad too, will I need special tools to remove it? I'm hoping it's just the expansion valve. I know the drier needs to be changed too, but should I replace the pressure switch also? Thank you, in advance, for taking the time to answer my questions!!
Reply With Quote
Old 03-22-2002, 07:52 PM
Registered User
Join Date: Dec 2000
Posts: 368
Yes, you can replace expansion by just removing bottom dash cover. It's tight, but it can be done. I am not too sure about this, but you might have to remove one of the supports as well. I think it gets in the way and you can't quite slip in the necessary tools. Hope that your expansion is the only problem otherwise you need to remove the whole dash. The 126 is one of the most involved, there are just too many screws.

Reply With Quote
Old 03-22-2002, 08:34 PM
Posts: n/a
Expansion valve on your 420SEL is likely in same place as on my 91 350SDL(126) - directly above driver's right foot when on the accelerator. Driver may be able to kick it with right toe. Local, best-in-town, AC guy replaced mine about 3 yrs ago. We removed only the panel at driver's knees for access to the valve.
Reply With Quote
Old 03-22-2002, 09:51 PM
Registered User
Join Date: Mar 2002
Posts: 14
O.K. guy's...thank you VERY much for the info... I was hoping someone would tell me that. I enjoy working on my own cars but I was a little intimidated by the thoughts of having to remove an airbag! Thanks again!
Reply With Quote
Old 03-22-2002, 11:05 PM
jbaj007's Avatar
Registered User
Join Date: Jun 2001
Location: Santa Monica, CA
Posts: 2,053
The expansion valve is relatively easy to access, but there is one caveat. The bottom pipe retaining nuts (two) aren't too bad, but don't "horse" the upper ones or you'll flex the pipes and have an evaporator leak that you didn't have before where the pipes join the evaporator (weld).
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)
Reply With Quote
Old 03-22-2002, 11:31 PM
Senior Member
Join Date: Apr 1999
Location: Walnut,CA,USA
Posts: 554
You don't have remove any air bags,just remove driver side under panel,side panel and you must have the right tools to do this job I'll leave this job to a pro "trust me" you don't wanna damage your evaporator it evry costly.
MB STARS Master Guild Technician,17 years MB tech
14 years independent shop owner
Reply With Quote


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

Similar Threads
Thread Thread Starter Forum Replies Last Post
84 500 SEL frequency valve question pmckechnie Tech Help 1 03-04-2003 08:25 PM
Expansion valve, need advice J.HIDALGO Tech Help 11 07-04-2001 05:21 AM
Leak around expansion valve wjm Tech Help 5 06-28-2001 05:13 PM
M103 Valve guides edbardzik Tech Help 3 06-01-2000 07:37 AM
88' 420 SEL trans. fluid change Jim Collins Tech Help 2 09-12-1999 09:18 PM

All times are GMT -4. The time now is 01:42 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page