Hey Cleeves, very impressive progress !
Can you share some details for the archive's sake, of the installation of the vac pump diaphram. I recall the internal mechanism had to be either in or outward in stroke before setting the diaphram.
Great work!

Also good work on the odometer etc.

re: AC, check the fuse first. Other than that I do not recall any AC/blower stuff behind the gauge cluster.

"My $230 inspection from a local mechanic was a waste of money, this is something they should have easily caught. 2 bad check valves and multiple leaky old hose connectors, it seemed every branch of the system had zero vacuum except the brake booster. How this got past multiple mechanics I don't know."

yes this is sad. Painful to hear about this. Dreaded !
Where were the bad check valves? Anyway, hope you get it along.

Might as well make sure the short hose to the shut off valve is sound and no oil on the end of it. Oil indicates pending failure of the shut off valve located at the back of the injector pump.
I don't mean to raise another issue but worth monitoring.

Cheers !

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

Vacuum pumps do not usually make squealing noises. Belts do.

With your new used pump, listen to it with a stethoscope to hear what it sounds like, make a recording of it as a histogram using a head set mic on your phone as a contact mic so you have it for future comparison.

I've never had a vacuum pump failure but when they do, they could drop shrapnel into the engine and possibly destroy it. So you want to keep an eye/ ear on it.

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Hi unkl300D,

Thanks for the kind note! It's not my first time working on old German cars - I've done much worse jobs in the past on a BMW E24 I had. Like when I hit a pot hole and busted the oil pan and had to lift the engine to replace it. Good thing this 300D came with a stock suspension system.

The existing diaphragm held vacuum just fine, so I left it alone. I did pop the valves, clean them with De-oxit D5, and replaced the seals on both ends. The bearings appeared to be in good condition from my inspection, so I left them alone. I would think that you'd want to install the diaphragm in whatever position is at the extreme (axially) during a normal cycle, so the rubber isn't over stressed. If I had to do it again, I'd just compress it with a c-clamp and measure with a micrometers to find the correct one.

The dead check valves were the ones on the driver's side of the engine bay near the firewall. When I say dead, I mean dead as in zero vacuum from the pump side.

When I had the gauge cluster out I pulled the shutoff valve hose off of the ignition switch and tested with a mitivac - no oil and 27 in of Mercury. The other end was on really tight so I didn't want to pull it.

Make sure to note that my heater blower is also inoperative now as well as the A/C, which could be a valuable piece of information to someone who knows the idiosyncrasies of a W115 very well.

Funola,

After writing that post, I had the same thought but didn't get around to expressing it. The A/C belt was nearly shredded and I think that the noise just somehow coincided with the vacuum pump failure and led to that assumption. Consider my initial diagnosis from the viewpoint of a general practitioner poking in the ER to make a quick fix rather than a cardiologist at the 4th checkup.

I'll make sure I wear a white coat using the stethoscope.

Henry C.

Thank you for the update and clarification. Posts like these help out many folks.

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

Personally, I think that 125 for an oil change is high.
I do mine myself, but the local indie uses Mobil 1 and a Mann filter+gaskets+crush washer and he charges $75. That's pretty good given that the oil is 30.00 and the filter 15.


But it's easy to do this change quickly.


Consider doing it yourself, no special tools required, I think, just 10mm and 13mm wrenches preferably box wrenches or sockets.

__________________
Strelnik
Invest in America: Buy a Congressman!

1950 170SD
1951 Citroen 11BN
1953 Citroen 11BNF limo
1953 220a project
1959 180D
1960 190D
1960 Borgward Isabella TS 2dr
1983 240D daily driver
1983 380SL
1990 350SDL daily driver alt
3 x Citroen DS21M, down from 5
3 x Citroen 2CV, down from 6

Hi strelnik, thank you for the tips!


In other queries, I found out that one of my tail light gaskets is a bit leaky when I opened the trunk after a hard rainstorm today. My trunk is rust-free and I want to keep it that way!

Does any one know if this is the right gasket?
Mercedes W114 W115 /8 Rückleuchte Dichtung Dichtrahmen 1148260158 TOP | eBay

Is there a gasket difference between the '68 - '73 and '74 - '76 ? If so, does anyone know the part number for the latter? Having difficulty finding this part on the webs.

Thank you!
Henry C.

Also, any one have a Mahogany driver's seat plastic piece for the right side of the seat? Mine is cracked and I'd like to find a new one. I may end up posting a new thread about this to get more views from people with boxes of parts sitting around.

Warmth,
Henry C.

You could probably buy the entire used lens,gasket and lamp holder for that much ! go to reinventhewheel and ask the guy.
otherwise just use black RTV silicone sealer to help seal around the old gasket.

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

mahogany?

ask reinventthewheel.
also another guy on this forum, hogweed is a decent chap. he parts oldies.

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

Yeah, I thought about that, but I'd really like to get a new genuine MB gasket set for this. They are getting quite old and I may sell at some point - I want to have a long list of parts and have everything very minty.

I'll ask on reinventthewheel, but I don't see the part listed there.

Warmth,

-H

Another simple thing to check is whether the water is wicking its way into the trunk along the studs going through the gasket from the lens. I was tracking down a mystery leak in my 1976 240D (w115.117) for years before I finally figured it out from the trails. I just wrapped the stud in teflon tape and it has been dry for several years now. Replacing the gasket hadn't helped any (although probably still good I had replaced it anyway, long term). The lower corner stud was my leak source, which makes sense when you look at how water flows over and around the lens.


If you PM me (or post) your VIN, I can plug it into my (actual, not Russian) EPC and look up the part number for yours. I've had excellent success with that for my 240D so far.

Cheers,
-Bruce

__________________
1976 240D [W115.117/616.916] (acq 11Jun76)
1990 MB 300D 2.5 Turbo [W124.128/602.962] (acq 4Sep15)
1991 SL250d (ex-300SL-24) [R129.061/OM602.962/722.6, was M104.981] (acq 25May12, converted to diesel)
1993 Jeep Cherokee [XJ] (acq 12Apr14)
1999 SLK23 AMG Sport [R170.447] (acq 12May21 **FOR SALE**)
2008 E320 CDI [W211.022/642.920] (acq 27Jan24)

-- Deceased...
1993 300D 2.5 Turbo [W124.128/602.962] (totaled by Dominos driver 28Mar12)
2007 E320 CDI [W211.022/642.920] (totaled 18Dec23)

Hi Bruce,

I went out to check again late last night and found that the tail light enclosure was filled with water from a rainstorm that happened 6 hours prior. It dumped water all over the ground when I undid the screws. Does this help you to confirm this diagnosis or does it perhaps lead to a different one?

Also, I want to replace my subframe bushings and sway bar links just for the sake of it because they are at least 20 years old. I know at least one of the subframe bushings is bad. Do I have to use the MB ones, or will a cheaper brand be sufficient? I do not want something that will be deteriorated in 5 years, but 20+ is OK.

I will get you the VIN number later today.

Thank you!

Henry C.

Will do. Thanks!!

Henry C.

... sorry, late getting to the thread.

that jewel needs some polishing for sure, but YOU can do it.

I wouldn't take it to any garage.

if you have a classic repair center nearby, I MIGHT take it there... but I'd need to be $$$

everything the car needs can be fixed yourself... but it takes time and patience.

for the oil change... get a topsider oil change pump, and suck it out the dipstick tube, and then swap the filter elements. oil is around 15/gallon *(you need two) and the filter should be around 15 as well... so... 125.00 is a bit pricey.

PLEASE DON"T TAKE THIS CAR TO NEW YORK IN THE WINTER!!!

it is a frail chassis, rust will destroy it in short order.

Belated Welcome to the forum! get your signature line, and UserCP info updated so everybody knows where you are and what you have!

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

I didn't even know topsider pumps existed for this purpose. Shows you my bank of knowledge when I purchased this. So this car take 8 quarts of oil? Seems like a lot!

Thank you for the welcome ! I will only take it to New York if I can afford a garage. To be cheaper, I could get a garage on the outskirts of town and just use it for road trips to New England in the summer. Well, it will be in Atlanta for at least 3 years given the length of my academic program. May sell it before then if I get it 100% and it seems like it rolled off the showroom floor. I think this car has that kind of potential. I prefer working on cars that are cherry and making everything 100% over than spending time keeping a $1k rustbucket on the road.

Also, just found that a MB OEM transmission mount piece is over $300 from peachparts. That is ludicrous!

Henry C.