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 > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 07-01-2016, 02:20 PM
Registered User
 
Join Date: Jun 2016
Posts: 2
W126 Expansion Valve Tutorial?

Working on a friend's 1984 280SE (Euro spec) with the M110 six. Replaced the bad clutch on the (York/R12) compressor and topped the system off with Freeze 12.
Pressures seem good (170H, 40L) but very little cooling from the vents. Leads me to believe defective expansion valve.

Apparently could be the aluminum block expansion valve or the old style brass/copper bulb type.

Is there a tutorial for replacing the expansion valve?

Or am I barking up the wrong tree?

Reply With Quote
  #2  
Old 07-01-2016, 06:41 PM
Registered User
 
Join Date: Jan 2012
Posts: 7,534
Any history on this car?

If the expansion valve was not opening enough, the high side would be going very high and low side very low / suction.

Is the large hose leading from the evaporator to the compressor cold maybe frost covered? If so , the expansion valve is working.

You might have a stuck open heater valve / blend door staying in the hot position. Feel both heater hoses, are they of equally hot temperature? If so the heaver valve is open.
Reply With Quote
  #3  
Old 07-02-2016, 01:13 PM
Registered User
 
Join Date: Jun 2016
Posts: 2
Quote:
Originally Posted by 97 SL320 View Post
Any history on this car?

If the expansion valve was not opening enough, the high side would be going very high and low side very low / suction.

Is the large hose leading from the evaporator to the compressor cold maybe frost covered? If so , the expansion valve is working.

You might have a stuck open heater valve / blend door staying in the hot position. Feel both heater hoses, are they of equally hot temperature? If so the heaver valve is open.
The high side line is noticeably warmer than the suction line but the suction line isn't cold.
No history on the car, came to me with a bad compressor clutch but free compressor and some refrigerant still in the system.
Replaced the clutch and topped off the system.
Reply With Quote
  #4  
Old 07-05-2016, 05:10 PM
Hit Man X's Avatar
I LOVE BRUNETTES
 
Join Date: Sep 2004
Location: FUNKYTOWN
Posts: 9,087
Thumbs up

Freeze 12 never worked well in my experience, I seem to recall it being a mix of R134A and other crap. Was this in the system before the top off? If you have no idea, it could be full of ambient air for all you know. BTDT with unknown vehicles.

You do not have a TXV problem.

You have an inefficient condenser with tiny aux fan, this is the major issue. Go back to R12 or try R152A.

Were your pressures checked at high idle? Aux fan working? How about that fan clutch?

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.
[/IMG]
Reply With Quote
Reply

Bookmarks


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 11:39 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, 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