Does anybody know the part # for this line? From the oil filter housing to the oil pressure guage? 1980 300SD. Mine is starting to drip a little from where the plastic line meets the metal. Not where it threads onto the gauage, but right where the plastic line ends. That end fitting rotates freely on the plastic line.

Anybody ever fix that? I wonder if I can just cut it off and press it into the line again. Maybe with a little heat?

Otherwise maybe a plumbing compression fitting might work. Does anybody know what the thread dimensions are for the gauge?

It definately had a big leak prior to my owning it because I spent about 6 hours scrubbing carpet with dish soap to get all the oil out last summer. Do not want to repeat that! haha

I did this on my 1984 300D. For it, the part number was 1235420644. I bought an OEM part.

From my research I have found nobody seems to have "fixed" this with the existing part. I did hear some hokey ideas like putting plumbing gasket inside the mating connection although I don't know what you would do if any of it were to break off and make it's way inside the engine which seems plausible. What I didn't find is that the oil pressure line also has a tiny gasket which may also leak. In most cases, it is not simple to tell which one is leaking so it's probably best to do both. IIRC, the gasket cost a few dollars from a MB dealer. You need to let it drip for about an hour once removing the old gasket otherwise you're taking a chance the new one won't mate properly.

Dkr.

Mine has the same part number as post #2.

The line is sold as a complete assembly. Run the part number given thourh the Pelican site.

When I removed My Oil Pressure line when I removed the Oil Filter Housing to change the Block to Oil Filter gasket I found that the Line Fitting was rusted and filled with gunk to the Line and the other Fitting.

Meaning that the whole line turned in stead of just the Fitting with the Nut on it.

__________________
84 300D, 82 Volvo 244Gl Diesel

Thanks for the part number! So Diesel911, the nut down at the filter caused the whole line to turn because it was seized up? My leak is at the gauge inside the dash. I think I'm going to try reinserting the metal barbed end after making a new cut in the line. How tight should that end fitting be (at the gauge side)? Right now it does rotate with some slight resistance. Should it be so tight it cannot rotate? How does one thread it on the gauge then? Or do you have to loosen the nut at the oil filter for the line to turn?

The barbed banjo bolt fittings on the fuel lines do not turn, so I'm thinking this one should not rotate either.

That part number above led me to this diagram where they have 5 different part numbers listed for this line. All with different prices. Are you sure this number is correct for a 300SD?
This fellow found a line but said it was for a 123 (as is the part# given above) and too short: 300SD oil pressure line solution?

SPEED SENSOR,SPEEDOMETER FLEXIBLE SHAFT AND OIL PRESSURE GAUGE LINE. Fits: Mercedes | Mercedes-Benz of South Atlanta

Thanks for your help guys! Winter is now and I need to get it fixed soon.

Ok I got it fixed! I didn't realize the fitting at the gauge was a two piece design. A nut that spins freely over an inner tube that presses into a bore inside the large nut on the gauge. I'll attach a photo.

So, I'm not sure now if my leak was coming from the plastic tube, or from under the nut. It was likely under the nut but I assumed it was already tight. I did just have it hanging all kinds of ways while I was removing my steering lock though, so maybe it did come loose somehow. Anyway, while I was examining it, the plastic tube snapped close to the nut. It's rather delicate tubing. So, I was able to pull the broken end off the barbed ended with some vice grips while the nut was in a bench vice. It was super tight. I doubt it would have been leaking.

I cut a fresh slice off the end of the tubing with a plumbing pipe cutter. The kind you spin around the pipe and it cuts through nicely. After that I heated the tube up with a lighter until it was smoking, I just passed it around the flame back and forth heating it slowly. Eventually when it was quite hot I quickly pressed in the barbed end. I had to press pretty hard. It's super tight fitting. I had to put the end of it against the dash and push down hard on the tubing to the point where it could have cracked the tubing again. But it slid on thankfully. Put it all back together, and no leaks! For now...

Attached Thumbnails

 

If that line snapped off, that should be telling you something.
That is old, and what will keep it from maybe snapping or cracking again?

Your fix might work, but with the high oil pressure coming into the line, I would be nervous about a bad leak again.

If the line is still available, I would just order one.


Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

I agree.
Assuming it cracks in the same place againg at least he will have some warning when it drips inside.

Only time will tell.

__________________
84 300D, 82 Volvo 244Gl Diesel

Well it's hard plastic. Do you think you could take a new line and bend it without it snapping? I bought a new hard fuel line and it seems just as stiff as the old one it replaced.

Besides, it only snapped because I had twisted it and the loop of it had gotten stuck inside the dash. I just wasn't paying attention.

45psi is where the needle pegs. It probably goes to at least 80 when the car is at redline. Even so, that's pounds per square inch. The inside of the line has a tiny circumference. Like 0.37 inches. So each 1/8" of line has about 0.05 square inches of surface area. Therefore that 1/8 inch of line is only holding about 3.7 pounds of force spread along the entire circumference. Each tenth of the circumference only being 0.37 pounds of force. It's really not much.

I was pulling and tugging on the line with all the force I could - to try and get the end off the barbed connector. That plastic would not crack or rip at all. Yet it did snap when I bent it in the dash. Maybe because my garage was cold near 0 Celsius? Maybe a new line would be slightly softer and more forgiving. But I'm not scared of it just suddenly bursting. There isn't enough pressure inside that tiny line to cause that to happen. And the line experiences no forces on it while it's inside the dash.

I'm more worried about my axle boots! Now those are looking like they're on the edge of bursting open!

If your boots are cracked badly, now is the time to replace them! BEFORE the fail, and you damage the joint!

__________________
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 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

The highest possible Oil Pressure you can have is 110 psi which is what the Oil Pump Relief Valve opens at.

On mine I can get 95-97 max psi even if I reeve up a hot Engine.

Only Merceds know why they made the Gauge the way they did.

__________________
84 300D, 82 Volvo 244Gl Diesel

It' a "Representation" of what an oil Gauge MIGHT look like in action.

__________________
'84 300SD sold
124.128

As for the oil line, an update here says it is part number: 116-542-12-44
300SD oil pressure line solution?

Just to confirm this line part number: 116-542-12-44 does fit the w116 and is the right size.
It's about 52 inches long, and comes with the grommet. Once in the cluster can be pulled out almost a foot and the line coils up and the fitting at the end has a nice 90 degree bend in it to keep it from hitting the air duct. I'm not sure what car mine was from but it never had the bend and the grommet was MIA.

The new line is quite flexible. The old line is very hard. It snapped in half just trying to get it out of the car. It cost $70 here in Canada at the dealer.

Attached Thumbnails