1985 300TD Project - PeachParts Mercedes-Benz Forum

cek1 · #1 04-14-2014, 08:24 AM

Well, its been a while since I've been behind the wheel of an MB. I last had a '90 300SE 7 years ago. Before that I had an '84 300D from '02-'06. I've checked in here from time to time to see what was happening over the past 7 years. After a 2 month search I happened upon a '85 Light Ivory 300TD that was sitting around a farm up in Bucks County, PA. 233k, needs some maintenance to bring it up to date but I'm looking forward to investing some time (money!) into it. With 2 kids now I need a weekend car that has some room to haul kids/stuff around in and make some trips. This won't be a DD, I have an '01 TDI Golf (250k) to get me to work 60 miles each way.

Anyway, here are the initial picks in the driveway:

toomany MBZ · #2 04-14-2014, 08:52 AM

Looks good, keep us posted.

cek1 · #3 04-14-2014, 09:57 AM

Thanks for the comment. Just to shed some light on where I'm at with it. I test drove it a few weeks ago after looking at a 240D the PO also had for sale. They had the TD sitting across the driveway, not yet for sale. After a test drive and a peek around and under, I was set on it. Made an offer and after a few weeks picked it up. Drove it home Saturday morning.

Few things on the list to get sorted:

1. PO says it sometimes fails to turn over
2. Brake Pedal stiff and has some pulsation
3. Clunking on hard right turn from the rear
4. Vacuum issues everywhere(stiff brake pedal, wont shut off, locks......)
5. Fluids/Filters
6. Throttle linkage adjustment
7. New driver door (hard to see in pics but the PO hit a post on a tight driveway turn)

My searching says:

1. Ignition tumbler or electrical switch (picked up both)
2. Vacuum and new rotors/pads
3. Rear Sway bar link or Half shaft
4. Bought a hand pump with gauge for testing and some new connections
5. Just do it
6. Need to find a good adjustment how to
7. Want ads/junkyard

cek1 · #4 04-14-2014, 10:25 AM

I started in yesterday learning about vacuum and how to test. I had full and consistent vacuum from the pump. Then I went to the yellow door lock check valve. Wasn't even hooked up. Hooked up.... still no shut down. Plugged it off and now it shuts down but a little slow.

I put my pump on the fuel shut off valve. Shut off instantly on the first pump. So that checked out good. Replaced a few various rubber vacuum connectors (some shorter connectors, the big 4 way connector, another big 3 way connector). Where can I get that 4 way connector that's in the above picture? I haven't seen it online. It feeds the doors (2 yellow lines), the ACC (green/yellow), and the ignition (brown). It looks different then the big 4 way that I received in a kit and used in another spot. All of the lines going in feel a little loose.

Now that it was shutting down I was happy but the fact that it shuts down a little slowly means there is still more work to do. I put the pump on the on the brown line (headed to ignition) and then the green line (ACC). Pumped it up and neither holds vacuum. I'm pretty sure the climate control should hold vacuum right? Not sure if the ignition brown line should or not.

As far as the clunking I took the driver side wheel off and the sway bar link is loose and I'm hoping replacements will cure that clunk. The axle boots are slightly cracking but not leaking and couldn't find any tears.

toomany MBZ · #5 04-14-2014, 11:40 AM

1. Could be a funky neutral start switch. More common failure that an ignition switch.
2. Vacuum, definitely for a stiff pedal. Pulsation, warped rotor/s. You've got that covered.
3. Right. If the boot doesn't leak, you're good.
4. Good.
5. Right.
6. The link to the online service manual is not currently working, but there is an explanation in there. Too large a file to send here.
7. Right.

You probably have a leaking door lock actuator.

I think your shut off actuator and ignition switch are fine, I would not replace those. If you use a different tumbler, you have to use the key for that.

You should be able to find a four way connector here on the site, click on the Mercedes Benz button at the top of the page.
The one in the pic looks different because after 30 years of being bent, it, well, looks like that. The new ones are a + looking affair.

cek1 · #6 04-15-2014, 09:10 AM

Just ordered my big parts lists. Putting that Pelican to work. So I hope to have the parts here Friday when I have some time to continue diagnosing and start replacing known issues. I went ahead and got the + 4 way connector here and some of the smaller Y 3 ways. My first order of business will be to get the new sway bar connectors on the rear. Then a good test drive to make sure the clunk is from the loose driver rear one.

Did replace all of the fuses with new copper ones because its cheap and I felt like I did something.

cek1 · #7 04-19-2014, 08:41 PM

Some parts came in. First job was to get rid of the clunk in the rear end. Does this look bad to you?

Replaced both sides with new lemforder links.

Test drive revealed the clunk is gone.

Next project, rattling air cleaner. Removing air cleaner revealed broken mount. Had another one in the garage so I replaced. No more engine rattle and knock. Bottom bolt on the mount took me quite a while. No pictures, hands where to greasy. The old mount broke at the bolt where it mounts close to the valve cover.

Now I need to investigate vacuum. I've been searching a bit reading everything I can. I may start a separate post for some help there

Mölyapina · #8 04-19-2014, 09:08 PM

Quote:

Originally Posted by cek1

1. Ignition tumbler or electrical switch (picked up both)

Could also be this, but I agree that the NSS would be more likely.
Stranded in parking lot, had to do the hammer trick

cek1 · #9 04-20-2014, 09:25 PM

Ive started the car 50 times at least in this past week testing vacuum. Not once has it failed to start. I'm sure it will be a poor time when it does. So the starting issue is on the back burner.

Today I replaced a few more vacuum connections. Last few on the vacuum transducer. It shuts off quick, just as I remember on my old 84. Brake feel is still not right. Going to test booster vacuum, do new rotors, pads on front, then flush the fluid.

Where can I get this?

uberwasser · #10 04-20-2014, 10:16 PM

Most any parts site, including this one.

Link to parts on PeachParts

Part # 1170780045

You may also need some three way vacuum connections.

Part # 1170780145

Diesel911 · #11 04-21-2014, 12:48 AM

You might need this later.

Neutral Safety Switch Troubleshooting 84 300D
Neutral Safety Switch Troubleshooting 84 300D

Neutral Safety Switch Bypass and Wire Junction/Terminal Block to attache Jumper Wires so you can Crank the Starter bypassing the Neutral Safety Switch on W123 with a Turbo Charger.
84 300D turbo diesel has power but will not start or crank!? - PeachParts Mercedes ShopForum

ROLLGUY · #12 04-21-2014, 06:59 PM

Oh drat, it's a Federal emissions car so I can't sell you a trap-ox bypass pipe

....Rich

zakatekaluka · #13 04-22-2014, 09:12 AM

Just got one of these, too, cek1, and I spent my weekend doing the PITA vacuum diagnosis, so I feel your pain.

Something to try... On the main vacuum line from the pump to the booster, those two offshoots that feed vacuum to everything else can get clogged. I've had two 85s now that had one of those two ports clogged completely (on my TD the one leading to the door lock system was so gunked up it didn't even look like there was any hole there at all, and on the "new" wagon, the first one, to the transmission, was just as bad). Might be worth having a test with a vac tester right at each of those ports, but be carefully as they can snap off easily. In each, I just put a pin in there and wiggled it around, pulling out the crud. I did end up replacing the lines, because they are only around $30 and if that port is clogged, how does the rest inside look, hm? But the pin trick worked like a charm while waiting for the parts to get here.

Also, please take note...your ride looks like it was well maintained. I buy $800 Save 'Em Specials, so it might not be an issue at all for you!

cek1 · #14 04-23-2014, 09:20 PM

Don't worry, I went to see if the brake booster would hold vacuum and broke both nipples off. New line in place today. Booster holds vacuum. I'm going to do front rotors, pads, soft lines so I'll flush the system and see how the pedal feels. I need to put a few miles on it and see how it's driving and shifting now that the vacuum problem is isolated to the doors and hvac.

Did fix the saggy bumper strip on the rear. Palmolive and bending it back on itself as you push did the trick. I just followed some posts on here after a search. A few blows with a rubber mallet helped get the last bit in.

I may spend a little time cleaning the interior tomorrow until the next batch of parts come in. Run a diesel purge to. I have off all week but my wife doesn't so my little guy and 5 yr old are keeping me busy. I would spend all day outside if I could!

cek1 · #15 04-27-2014, 08:59 PM

Did some maintenance this weekend.

#1 New hatch struts
#2 Diesel purge
#3 primary and secondary filter
#4 new return hose
#5 oil filter and oil
#6 Sls fluid flush and filter
#7 power steering fluid and filter

Was some getting to know you time with the new car. Took it to the car wash for a good power wash and hit the gas station for some fresh fuel (gauge was at a quarter wasn't sure how accurate but appears true). Took a nice 10 mile drive and the TD runs great. Not smokey in the slightest. Shifts firm no flares. I like it! I need to take more pics while I'm working. I'm usually chasing around a 17month old while im working though. I'll make sure I have the camera out more often.