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 > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #166  
Old 07-16-2018, 01:45 PM
Registered User
 
Join Date: Feb 2016
Location: North New Jersey
Posts: 380
I tested my pressures yesterday, it was fairly hot (high 80s) and after about an hour of driving with AC on and off. (I'm running r134a currently and at 80% of the weight of the r12 that is specified for my car.)

In my driveway will all windows/doors open and AC on max the pressures read at about these values - slowly going up and down within these ranges:

LOW: 37-40
HIGH: 280-295

With High side peaking once at 300 before dropping down into that range listed above.
I'll see if I can pull and test my evap temp sensor.

I feel like my compressor has a bit of a very slight grumble/grind in the moaning noise - but I know it has somewhere around 7 ounces of ester oil and that nothing has leaked since I installed.
__________________
Andrew
Montclair, NJ
--------------
1982 300D Turbo
117k
Petrol Blue/Green
Reply With Quote
  #167  
Old 07-16-2018, 03:17 PM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Location: Texas Hill Country
Posts: 3,736
Pressures are roughly where they should be if running the stock system. High side will be elevated due to reduced efficiency compared to the small-tube condenser or a parallel flow condenser. I'd be looking squarely at that ETS if you froze up. It's been said before, but I'll say it again. CLEAN THE EVAPORATOR COIL. You don't need to pull the dash to do it. And yes, it's worth your time to do.
__________________
'11 Honda Accord EX - "The Daily" 64K
'83 500SL Euro - "The Money Pit" 116K
'86 300SDL - "The Diseasel" 185K
The Diseasel Thread - Everything You Didn't Know You Wanted To Know
>>>Teflon W126 Window Regulator Slides<<<
Reply With Quote
  #168  
Old 07-16-2018, 03:39 PM
Registered User
 
Join Date: Feb 2016
Location: North New Jersey
Posts: 380
Iím going to do this Diseasel - consider your advice heeded!

Replace (test first) that switch and clean. Do I need to remove the expansion valve to get to evap?
Reply With Quote
  #169  
Old 07-16-2018, 06:18 PM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Location: Texas Hill Country
Posts: 3,736
Need to remove the blower and go in through its opening. There are writeups on this forum and elsewhere on the Internet on what and how to do it.
__________________
'11 Honda Accord EX - "The Daily" 64K
'83 500SL Euro - "The Money Pit" 116K
'86 300SDL - "The Diseasel" 185K
The Diseasel Thread - Everything You Didn't Know You Wanted To Know
>>>Teflon W126 Window Regulator Slides<<<
Reply With Quote
  #170  
Old 07-16-2018, 10:12 PM
vwnate1's Avatar
Diesel Dandy
 
Join Date: Nov 2005
Location: Sunny So. Cal. !
Posts: 3,052
I'm confused now ~ earlier you said low side should be around 25#.......
__________________
-Nate
1982 240D creampuff 370,000 miles
1978 300CD back from the dead&1980 300CD 90K Miles ICE COLD AC ~ SOLD
1984 300CD KEEPER ! 426,XXX miles
1984 Euro 300TD Fully optioned SWMBO's
1974 350SLC 4 speed stickshift SOLD & missed
Krazy Kommie Ural Motos (3)
BMW Motos /5's SOLD
1959 VW #113 Deuxe Beetle, 36hp engine, stock
Junk, Rust
Arthritis, Crushed Spine,Broken Neck&Back
Memories &
Peace Of Mind
Reply With Quote
  #171  
Old 07-16-2018, 10:22 PM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Location: Texas Hill Country
Posts: 3,736
Quote:
Originally Posted by vwnate1 View Post
I'm confused now ~ earlier you said low side should be around 25#.......
His original posting in another thread said he was running 25PSI suction with similar head pressures to what he has today. 25PSI is low. Normal suction pressure is 35-45PSI depending on ambient temperature and load on the system. Low side pressure by itself is useless, it has to be factored with head pressure, ambient temperature, and load on the system to be a valuable number.
__________________
'11 Honda Accord EX - "The Daily" 64K
'83 500SL Euro - "The Money Pit" 116K
'86 300SDL - "The Diseasel" 185K
The Diseasel Thread - Everything You Didn't Know You Wanted To Know
>>>Teflon W126 Window Regulator Slides<<<
Reply With Quote
  #172  
Old 07-16-2018, 10:29 PM
vwnate1's Avatar
Diesel Dandy
 
Join Date: Nov 2005
Location: Sunny So. Cal. !
Posts: 3,052
Thanx, I *think* .

Agreed, clean the evaporator, it's dead easy : remove the blower motor and use a garden hose......

Mine was nowhere as dirty as the ones I see here but I cleaned it anyway to be safe .
__________________
-Nate
1982 240D creampuff 370,000 miles
1978 300CD back from the dead&1980 300CD 90K Miles ICE COLD AC ~ SOLD
1984 300CD KEEPER ! 426,XXX miles
1984 Euro 300TD Fully optioned SWMBO's
1974 350SLC 4 speed stickshift SOLD & missed
Krazy Kommie Ural Motos (3)
BMW Motos /5's SOLD
1959 VW #113 Deuxe Beetle, 36hp engine, stock
Junk, Rust
Arthritis, Crushed Spine,Broken Neck&Back
Memories &
Peace Of Mind
Reply With Quote
  #173  
Old 07-17-2018, 08:36 AM
Registered User
 
Join Date: Feb 2016
Location: North New Jersey
Posts: 380
Cool. Looking at the forums threads. Should I pick up some condenser cleaner foam like that have at Home Depot? And then blow it out with water and air? Iím assuming this liquid wouodnthen make its way out down the trans tunnel drain tube.
Reply With Quote
  #174  
Old 07-17-2018, 12:38 PM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Location: Texas Hill Country
Posts: 3,736
The foaming stuff works well if you can get it on the coil. I used the concentrated Nu-Brite for evaporators (green bottle) in a pump up sprayer on my SDL because I couldn't get the can of foam in there, the 123 may be more accessible. Consider using a toothbrush on a stick to clean all the muck off of there. Rinse well. Don't be surprised if it's a horror show in there, 30+ years of leaves, dirt, mold, mildew and other nasties don't make for pleasant viewing. Anything you wash off should come out of the evaporator drains under the car. Don't go crazy with the water or you may be cleaning up more than you were bargaining for.

Your reward for a disgusting job? Stronger airflow and improved cooling, not to mention allergies that aren't freaking out from breathing 30+ year old mold!
__________________
'11 Honda Accord EX - "The Daily" 64K
'83 500SL Euro - "The Money Pit" 116K
'86 300SDL - "The Diseasel" 185K
The Diseasel Thread - Everything You Didn't Know You Wanted To Know
>>>Teflon W126 Window Regulator Slides<<<
Reply With Quote
  #175  
Old 07-17-2018, 09:31 PM
vwnate1's Avatar
Diesel Dandy
 
Join Date: Nov 2005
Location: Sunny So. Cal. !
Posts: 3,052
Post Routine AC Service

I cheated and bought a remote viewer at Harbor Freight, it is incredibly cheaply made but works just fine, it's designed to crap out or loose a part & stop working the *instant* you're not uber delicate with it but for looking in there it's fantastic .

I waited for a cool day and sprayed some foamy cleaner in there and let it soak a bit, flushed with the garden hose (use a nozzle or suffer the consequence !) and never a dribble on the carpets ~ every bit of crud went right out the drain tube everyone touches then complains when it crumbles .

As the evaporator is light alloy you want to try to find proper AC evaporator cleaning stuff so you don't cause corrosion .
__________________
-Nate
1982 240D creampuff 370,000 miles
1978 300CD back from the dead&1980 300CD 90K Miles ICE COLD AC ~ SOLD
1984 300CD KEEPER ! 426,XXX miles
1984 Euro 300TD Fully optioned SWMBO's
1974 350SLC 4 speed stickshift SOLD & missed
Krazy Kommie Ural Motos (3)
BMW Motos /5's SOLD
1959 VW #113 Deuxe Beetle, 36hp engine, stock
Junk, Rust
Arthritis, Crushed Spine,Broken Neck&Back
Memories &
Peace Of Mind
Reply With Quote
Reply

Bookmarks

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




All times are GMT -4. The time now is 08:11 PM.


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