Repairing the hydraulic hose for SLS hydropneumatic suspension on the 1985 300TD Turbo Wagon (W123) Mercedes

Everyone with a wagon will eventually face the necessity of replacing the rubber high pressure hydraulic hose which runs from the pump on the head to the metal fitting on the passenger inner fender under the air cleaner. I just did mine. It's simple and inexpensive. All you need is a comparable length of high pressure hydraulic hose. I used Gates 6G2 3/8 9.5mm. It cost $14. The hose fittings are easily reusable (despite what two hydraulic hose repair shops told me).
Remove the air cleaner. Remove the hose at the banjo fitting at the pump and at the metal line at the fender. Note that that the fittings on the hose are made up of a large round outer portion which goes over the hose and an inner portion threaded into othe outer portion. Hold on to the outer portion with a vice or vice grip and unbolt the inner portion. Once the inner portion is removed, unthread the outer portion off the rubber hose. IT IS LEFT HAND THREADED..
Be careful at this point. The OE hose has about 30 small plastic inserts inside the hose. Carefully let them drop out onto a clean surface, noting the orientation of the insert. You will need to insert them back into the new hose.
Put the outer portion of the fitting onto the new hose. (REMEMBER IT IS LEFT HAND THREADED AND SCREWS ON TO THE RUBBER.). The hose will stop at a shoulder inside the outer fitting. Screw the inner portion into the outer portion. It is tapered and fine threaded. You will need to push down on it with moderate force to get it far enough in the hose for the threads to bite. Before doing the other end, reinsert the numerous plastic fittings. Put the fitting on the other end and reinstall the hose on the car.
With these instructions, the job should take about an hour and half. It could be done on the road if you have a second person to hold the vice grip when disassembling the fittings.
My hose sprang a leak on a road trip. No new hose was available so a mechanic took off the old one, cut off the leaking end and reinstalled the fitting. He cursed and swore for quite a while trying to get it back together. This was because he never figured out that the outer portion IS LEFT HAND THREADED. I only discovered it by accident after trying to thread it on for about 10 minutes right handed, and then when trying to remove it to figure out why it wouldn't go it, presto, it threaded right on as I unscrewed it.

By the way, the fittings on the power steering hoses look to be the same so I bet replacing them is just as simple and inexpensive.

Glove Box Door Latch Repair on the 1980 W123 300D & 240D Mercedes

As my 2nd formal “Wikka” I am again dealing with making a simple, repair to something plastic on our vintage W123 chassis Mercedes but this project involves working with “ABS” plastics which present a whole new challenge in chemistry… and also holds great promise in helping to learn how to make repairs to hard plastic interior trim pieces commonly used in these vintage W123 MBZ(s).

In any event I sought out the expertise of my local plastics specialty shop here in California [ browse http://www.TapPlastics.Com ] where they correctly identified my interior trim piece as mostly being made of “ABS” plastic and also suggested I do a small test on a piece before jumping into my project… and gave me other hnts. Where you can, it is best to use thin pieces of sheet “ABS” reinforce the back side of cracked and broken pieces. These thin pieces can be literally “fused” onto the piece being repaired. Common black drain pipe cement [ actually a solvent ] is a good choice, especially where the repair will not show through objectionably onto a finished surface of the repaired piece. There are also clear, more expensive, bonding/fusing “ABS” cement products available.

For this project I used smaller pieces cut from a small $1.00 remnant of “ABS” sheeting [1/32”] purchased at Tap Plastics and ordinary black “ABS” cement from the local hardware store.

This project was on a 1980 300D [W123] and from my “Indy” MBZ friend I understand that the failure mode of our glove box door latch was clearly the most common type of failure in this W123 chassis series. The latch just dose not engage and hold the door closed. So yes it’s best that you remove the entire door and then the plastic back panel and do your own failure diagnosis and then IF your panel is broken or worn such that the “U-shaped” latch spring will not stay in place… then you can decide whether you want to replace the panel or make this fairly simple repair and gain valuable “ABS” plastic repair experience. Reading the remainder of this Wikka might help you do your diagnosis.

Yes this inner panel has the MBZ part number embossed on it [P/N – “ 1236890583 ”] however my local MBZ dealer’s parts counter indicated that I would have to purchase other latch parts as well in order to get the panel [~$60]. These metal latch pieces are usually not broken. But armed with this P/N you should be able to find this panel [ aka “Inner Glove Box Door ” ] for ~$25+s&h.

So let me move on with my easy repair to this most common door latch failure that was on our 1980 300D… namely one or two of the small plastic posts [ in nautical lingo “dogs” ] on the panel… these “dogs” either break off or become worn down and “dog-eared” such that the “U-shaped” flat door latch spring will no longer stay in position. Photo #1 below shows what a new panel’s “dogs” look like:

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Photo #1


Moving on to what I think is a better view [Photo #2 below] that shows our actual panel during repair and the text and arrows in this photo help to explain what was done. Once you see and understand how the latch mechanism works and how the “U-shaped” spring must be held in position, the repair I made will make more and more sense. It’s just a matter of cutting/fitting and then fusing plastic strips onto the back of the panel to replace the function of the one or both “dogs” that might have failed. I chose to fuse two 1/32-inch “T(s)” on top of one another as shown for extra strength. This was probably overkill! Keep in mind that this is all on the back side of the inner panel and so appearances are of little consequence here as the repair will be hidden when you put the door back together… function is what matters here !

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Photo #2

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IF some of you DO seriously think this Wikka needs more in the way of text explanations and/or photos, let me know via the comment link below or personal mail [PM] on the FORUM and I’ll see if I can incorporate your ideas in a future revision/update to this Wikka!
Regards,

Mercedes 240D Fuel Tank Removal and Cleaning

My daughters 240D sat for a while and developed a algae problem. I cleaned the tank screen, quite a mess, and installed new inline fuel lines and main fuel filters. I added an algaecide and about 5 gallons of diesel to allow the algaecide to kill the algae. When that happens and algae settles to the bottom of the tank and looks like a layer of old wrinkly vinyl paint. It is not a solid sheet and will be picked up if disturbed. So I decided to take the fuel tank out and clean it with my pressure washer. If that did not clean it enough I would have it steam cleaned.
Of course getting the fuel out will always result in diesel spilling on you no matter what you do. I also had to replace the fuel screen rubber line. Below are the pictures of the job. the hardware and the tank in and out.

  1. Remove the first aid kit and box from hat tray in rear seats. 2 philips head screws. Pull the plastic first aid kit front up and towards the front. disconnect the sender wire and place out of the way.
  2. Drain the fuel tank and plan on getting diesel on yourself.
  3. Remove rubber hose from screen. The screen does not have to be removed at this time. Tape over the screen opening to prevent diesel from dripping in the trunk ( hymm how do I know)
  4. Unbolt the 2 vent lines under the tank on the drivers side of the car, get more diesel on yourself.
  5. Remove the trunk floor carpet and the wheel well plastic inserts
  6. Protect the trunk floor with plastic, Diesel will drip out of the tank. Not alot
  7. Unbolt the forward trunk wall. 4 bolts 2 on the rear seat hat tray and 2 on the floor.
  8. Remove the vacuum reservior. 1 push pin assembly at the rear on the rear seat hat tray. Disconnect the vacuum line and move to the side.
  9. Unbolt the 4 fuel tank mounting nuts, remember the large washers are on the top.
  10. Remove the tank by moving the driverside towards the rear first and sliding the filler neck out of the body opening. spill more diesel on yourself or the trunk.
  11. Remove the fuel screen and sending unit.
  12. Clean with a high pressure washer or take it to a radiator shop to clean it.
  13. I attached my shopvac hose to the filler neck and duct taped it tight. then I turned it on blow and allowed the tank to dry this way for 4 hours. Make sure the vent lines are empty of water. This may require rotating and moving the tank to get the lines to drain. I used a flashlight to see into the tank and it looked quite clean.
  14. Before reinstalling the tank, blow out the supply and return line and change the filters.
  15. Use an algaecide every 6 months.
  16. OK you had an algae problem and had to do all this work. Since your there consider the following. Clean the screeen completely, I used brake cleaner in a can. Replace all the rubber lines you had to disconnect. You may have to reglue the bottom rubber cushions on the tank back on, use 3m weatherstrip adhesive. Open and clean the sending unit. If the tank had a algae problem so does your sending unit. Again brake cleaner spray. New screen and sender Orings. New filler rubber bushing if your is worn. Check your vaccum reservior, If cracked or leaking repair with epoxy. Check the vacuum line to reservior connector. Seal or replace if its bad. Your under the rear of the car so check everything. I treat the axel boots with 303 preservative while I'm under there, be careful not to break the boots if they are old. Again if you are doing this consider using an algaecide every 6 months or so.

The first picture shows the mounting bolts for the trunk wall panel ( this shows the lower one).
There are 4 bolts total... 2 under the hat tray of the rear seat (accessed from the trunk side), and 2 on the floor of the trunk.
Access for all 4 bolts is in the trunk.

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Passenger side upper trunk wall bolt and vacuum tank
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Passenger side tank area. Filler neck and vacuum tank
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Left side
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Left side, tank removed
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Right side, tank removed
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This is is what the water looked like that was drained out of the tank while high pressure washing the tank.
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Have a nice day!
And if anyone knows how to get the diesel smell out of my shop clothes, without a match, let me know.
3 washings and they still smell.

Door Lock Repair on the 1979 240D (W123 Chassis) Mercedes

This procedure was performed on a 1979 240D door lock. Other Mercedes locks may be similar.

Remove the door panel.

Remove the outer handle. There are three screws, two under a rubber grommet and one on the inside of the door at the front of the handle

Remove the pin that holds the tumbler assembly to the handle. I used a small nail with the tip ground off held in vice grips. Be careful, there is a small spring in the assembly. Don’t let the spring shoot off into a bush (ask me how I know).

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My leaves seemed to be gummed up causing the lock to not work. Soak the tumbler assembly in carburetor cleaner and scrub with a toothbrush. You can also use a piece of wire to dislodge the large chunks.
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Carefully remove and number the leaves and their springs as they become loose. It helps to use a pin to gently pry out the springs. Be careful not to stretch them, if they won’t come out gently soak the whole tumbler more. After soaking for awhile the leaves that are still stuck can be freed by rocking them back and forth with your thumb nail. Keep soaking and scrubbing until all of the leaves are free.
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Scrub all of the muck out of the handle where the tumbler slides into the handle with a toothbrush.
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Once everything is all clean carefully re assemble the tumbler. This is what it will look like when it is all free and re-assembled.
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Insert your key into the tumbler All of the leaves should line up flush with the tumbler when the key is inserted.
My tumblers would not align because of worn leaves and a worn key so I took it to a Locksmith to have a new key made and the leaves repaired.
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If you didn’t look carefully at the whole assembly before you took it apart don’t worry, I did the same thing and puzzled through how to put it back together for you. Once the tumbler is in the handle place the spring over the end of it, then use needle nose pliers to hook the ends of the springs on either side of the catch.
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The rod that pins to the end of the tumbler should be oriented as shown in the picture.
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Press the pin back through the rod and tumbler, then reinstall the handle and door panel.
Enjoy your working lock!

Replacing the A/C Evaporator on the 1983 240D & 1982 300TD (W123) Mercedes

Photo step by step post showing a W123 evaporator removal (1983 240D and 1982 300TD) (LARGE FILES)

These pictures are from replacing the evaporators in my Daughters 1983 240D and my 1982 300TD. Not every little step is included. As you progress you will figure things out. This is not a terribly difficult job. Just time consuming. AC knowledge is required for this job and a 609 license is worth while. Not mandatory but preparing for the test teaches you a tremendous amount about the AC system.
Notice some pictures are labeled 300TD, 240D and 300TD/240D. I am trying to show pictures that are specific to the model listed. IF I have not listed a car then it applies to both. What is specified for the 300TD will apply to the 300D and 300CD usually. This is for a “Automatic Climate Control III” for the 300TD as specified in the Mercedes Service Manual. And the “Heating/Ventilation and Air Conditioning I” as specified the Mercedes Service Manual for the 240D. The only difference in the 240D system is the car has the R-4 compressor not the York unit shown in the Service Manual.
Of course disconnect the battery, drain the radiator and you will have to recover any freon in the AC system.

Note, when looking at the pictures if the car is maroon in color it is the 240D. Signal red ( stop sign red) it is the 300TD

Any recommendations for this post will be appreciated.

Dave


001 Remove Mercedes symbol, this is not really necessary.
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002 Peel the horn cover off
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003 Pull the center of the cover off hub
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004 After removing bolt, Mark the shaft wheel relationship with a punch.
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005 Remove ashtray
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006 Remove center console carpet and remove screw
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007 Remove ashtray bracket mounting screws
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008 Lift front of wood trim above shifter and slide to the rear to remove
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009 Disconnect wires
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010 Slide towards rear to protect the pin, disconnect switch wires
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011 Pull radio
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012 Label radio wires
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013 Pull off AC control knobs
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014 Use socket to remove AC control nuts
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015 Pull AC panel and disconnect light units
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016 Pull switch out from the rear
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017 Pull all switches and remove the wire harness
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018 Using your fingers in the outside holes, push the wood trim out from behind
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019 Wood trim lifts at bottom first then out
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020 Disconnect the temp dial wires using your fingers. 2 harnesses
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021 Push in the top tab and remove the dial by pushing the unit into the console
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022 300TD/240D. Remove the outboard switches to remove the screws
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023 Remove both front seat inboard slide bolts in rear tunnel
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024 Remove drivers seat back panel. Unscrew it then slide the panel down. Or remove the entire driver seat.
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025 Remove the bolt holding the drivers seat armrest
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026 Remove screw covers on both under dash panels
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027 Remove screws
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028 Remove under panel side screws
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029 Remove under dash panels
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030 Drivers side under dash panel, side screw
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031 Remove center console carpet screws
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032 Lift center console from the rear. Watch top center of console and dash clearance.
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033 Guide center console carpets while lifting.
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034 Guide center of console over shifter.
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035 If you can’t remove the center console. Disconnect the tabs holding the carpet, 4 total ( Note: The manual does call for the driver seat to be removed. For the removal of the center console, the side carpets are the reason)
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036 Center console removed. The AC control panel is broken on this car.( I glued the unit together, A new unit has to come from Germany)
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037 Remove the floor heat duct under the drivers feet
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038 Removing the floor duct, drivers side , continued.
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039 Remove the cable harness on the drivers side of the floor duct
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040 More center console pictures
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041 Removing AC control bracket, (this will not normally be removed, it is pop rivited to the evap box. Switches must be removed from the panel)
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042 ID wire harness to switch connectors
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043 ID wire harness to switch connectors, continued
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044 Remove bulb spider for center console lights
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045 Clips that hold the Bowden cables to the side controls
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046 Plastic panel on Bowden cable mechanism. Positioning picture for repositioning after unbolting mechanism
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047 Wire harness to control
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048 Remove oil line and loosen speedometer cable in engine compartment so you can pull out instrument cluster far enough to remove speedometer cable. Remove wires
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049 Pull off light switch
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050 240D idle knob. Pull knob off straight back ( it’s hard) and unscrew chrome ring
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051 Unhook parking brake cable chain.
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052 Unscrew speaker grill screws on both speakers and remove grills
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053 Remove push clips center pins then base. 3 on bottom and 4 on top
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054 Remove glove box light and disconnect wires
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055 Remove glove box. Pry the top below the striker plate. Then remove the light wires
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056 Pry the A pillar molding off the A pillar Use a wide metal or plastic tool. Pry at the bottom then the top
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057 Pry at the top then move the bottom of the trim towards the center of the car. Watch out for the speakers.
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058 Remove the speaker mount bolts and speakers
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059 240D Disconnect the center vent cable from the vent mechanism.
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060 Remove the drivers side lower dash mount bracket completely. Note the screw washer combination and orientation of bracket
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061 Remove the passenger side lower mount bracket. Note the same info as above
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062 Disconnect both speaker wires from the dash.
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063 Remove the center support bracket completely so it does not hit the evap box
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Remove the dash from the passengers side first and move it out the passengers door. You will have to lift the dash off the defroster tubes on the evap box. Once lifted off them, it will come out. Watch the turn signal stick. Don’t break it. Don't twist the dash as this may cause cracking.
One word about reinstalling the dash. As you install the dash, the lip of vinyl at the front of the dash next to the windshield will curl up and make it difficult to get under the windshiled rubber. Using the same flat tool used to remove the A pillar moldings works well. Hold the dash in position and slie the lip under the weather strip.

064 300TD Replace the foam tube under the dash, I used a plastic unit
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065 300TD Move the amp wire harness
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066 300TD Remove the amp setup to allow the evap box to clear
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067 300TD Center console area.
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068 300TD Center console area upper section
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069 300TD Holding the center area wire harnesses
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070 300TD the center console area switches going though the wire locking strap
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071 300TD Right side wire harness holder
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072 300TD Remove the center connection under the vacuum switchs
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073 300TD Picture for identifying plastic tubes color codes
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074 300TD Picture for more plastic tube color ID
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075 300TD Vacuum tubes to center vent element
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076 300TD Disconnect plastic tubes to center vent element
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077 300TD/240D Uncouple the wire harness at the driver side floor vent
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078 300TD/240D Uncouple the wire harness at the drivers side of evap box
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079 300TD Remove the ETR sensor
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080 300TD Unclip the connector base on the drivers side case
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081 300TD/240D Unbolt and pull out both left and right support straps
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082 300TD/240D Unbolt the top bolt of the support straps, note the order
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083 300TD/240D Remove the heater core hose form the drivers side and passenger side (shown, see below for drivers side on the 240D))
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084 300TD/240D Note the positions of the clamp screws for reinstallation
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085 300TD/240D Tape over the heater core tubes to prevent water from dripping while removing
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086 300TD Remove the interior passenger side tube
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087 240D Disconnect the drivers side heater hose
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088 240D Remove the 2 passenger side heater hoses
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089 240D Move the heater hoses up above the vent area to prevent drips
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090 Evacuate the Ac system of all freon. Disconnect the Ac hoses at the expansion valve
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091 Unscrew the wire ground on the drivers side of the evap box
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092 Unzip the wire bundle lock on the drivers side of the evap box
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093 240D Either disconnect the Bowden cables or route all wires out of the bowden cables way for removal ( Again this panel was broken. You would normall disconnect the bowden cables)
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094 240D Pull fiber optic spider from AC control bracket
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095 Unbolt the switchover valve from the mount
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096 Disconnect the vacuum hose from the fresh air element
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097 Pull the flex hose from the drivers side and passengers side
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098 Detach the wire harness socket from the evap box
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099 Passenger side disconnect the fan wire harness
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100 Unbolt both mounting strap bolts at transmission tunnel. Do not unhook at the top. They are difficult to reinstall. Just place aside
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101 Unbolt passenger side top mount nut
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102 Unbolt middle section top mount nut
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103 Unbolt drivers side top mount nut
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104 Unbolt lower mount bolt
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105 It is best to completely remove the lower mount bracket so you don’t hit the evap box
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106 Remove the passenger side of the box first and pull towards the passenger door. Just like the dash. Watch for water leaking out of the heater core tubes
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107 Separating the heater box from the evap box. How to push the tabs
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108 Remove the tabs to separate the heater box. This tab and the opposite one on the box
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109 Remove the 2 tabs I’m pointing at to separate the heater/evap box
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110 Remove the left side heater box bolt. Save all parts
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111 Remove the right side heater box nut. Save all parts. Now separate the heater and evaporator box sections
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112 Separating the fresh air section from the evap section. Remove these 4 clips.
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113 Separating the fresh air section. Remove these 2 clips (6 total)
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114 Separating the fresh air section. Remove these 2 clips (Now 8 total)
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115 Separating the fresh air section. Remove these 4 clips (Now 10 total)
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116 Separating the fresh air section. Disconnect the element shaft from the door
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117 240D Separating the fresh air section. Either unhook the cable or unclip the cable housing from the mount. This cable operates the "main air flap"
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118 240D Separating the fresh air section. Remove the clip that holds the cable
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119 Separating the fresh air section. Unplug the fan wire harness
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120 Separating the fresh air section. Remove the wire harness from the base mount
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121 Separating the fresh air section. Unhook the wire harness form the box
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122 240D Separating the fresh air section. Remove the blower motor resistor unit from the evap box
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123 Remove and replace the fresh air element while you’re here
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124 Separating the evap section. Remove these 3 clips
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125 Separating the evap section. Remove these 2 clips (5 total)
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126 Separating the evap section . Remove the foam and these 3 clips (8 total)
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127 Separating the evap section. Slide the upper case off the evaporator
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128 Note clearance of expansion valve to evap box. Critical when reassembling unit. You may have to bend the copper tubes of the evap to install the new unit
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129 Note the position of the sheetmetal piece and foam. Foam also on the bottom
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130 Remove the black tar sealant from around the expansion valve. Note rubber sealing wall. Remove the rubber wall with the evaporator
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131 Note how much dirt is in the fins of the evaporator.
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132 300TD "Recirculation air flap" element
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133 300TD Heater core tubing
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134 300TD Close up. "Recirculation air flap" element
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135 300TD Close up. "Main air flap" element
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136 300TD "Center nozzle flap" section and element
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137 300TD "Defrost nozzle flap" element, located on the drivers side of the evap/heater box.
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138 300TD Center section of evap box
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139 300TD The upper element is the "Defrost nozzle flap" element. The lower element is the "legroom flap"
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140 300TD The expansion valve area.
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Some thoughts on this job.

The first car done, the 300TD, took a while to do. I did a lot and was a little lazy doing the job. The second car, the 240D took 3 days to do. We took lots of pictures and check everything over. I also spent a couple of hours re-gluing the AC control panel unit. I had ordered one and I eventually got it, but my Daughter needed to get back to school. I have it and will probably never install it I probably could have gotten the job done in one long day, but I don't like to work that way.



While your there. Consider replacing the following

All vacuum elements.
All vacuum connections
Of course the evaporator
Possibly the heater core ( this could be fixed with leak stop, I would not do this job JUST for a leaking heater core.)
All light bulbs
Check all the plastic vacuum tubes for damage.
Check the condition of the evaporator box and epoxy any weak areas.
Air temp foam tube, consider replacing it with a hard plastic tube
Evaporator box drain tube. I used a garbage disposal to sink drain adapter tube. ( make sure you install your tube before installing the evap box in the car )
Rebuild the instrument cluster, its out
Check all the vents in the dash for broken tabs where they mount. They use 4 tabs integrated in the vent to hold it in position, these break
Time to really clean up the mess under dash and center console

Here is the post I did that is just a word description of the evaporator installation. It has some lengthly considerations posted. This post along with the pictures here should be adequate for anyone doing this job.

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