Went to do the needle paint DIY on my 85 300 Turbo Diesel W123 today and found oil ALL over the inside of my instrument cluster. Now, it's not coming from the oil pressure gauge, but from the speedometer cable. Even looks like someone put sealant in the cable coming from behind the dash and into the mounting point on the back of the gauge. Why would there be oil in there and how can I stop it from going back into the gauges once I clean them?

burden tube is leaking or you didnt tighten it enough to the instrument cluster

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1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

^^^ Burden tube?



You might be leaking oil from the vacuum vent line (is that the same as a burden tube?). If so, that means your shut off valve or your vacuum pump is leaking .

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1983 123.133 California
- GreaseCar Veg System

there is a plastic tube (black) that is run from a fitting on the oil filter housing, thru the firewall, and up to the back of the oil/water/fuel gauge cluster. sometimes these tubes break, leak or are not tightened, I've even seen where someone disconnected it to look at the cluster and forgot to re-attach it. a little bit of oil residue inside the cluster housing is fairly normal. Especially for a diesel. to have puddles of oil inside is a sign of a problem.
My **bourbon** tube has a small pinhole in it and it seeps. I just have to remove it and sweat a little solder on it to repair. (if you can find the hole).

this tube (fed by the black tube) is a coil shaped copper tube that when pressurized it expands and levers and whatnot attached to it move the needle that you read oil pressure at.

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RIP: 80 300SD
RIP: 79 450SEL
2002 E430 4matic (212,000km)
2002 ML500 'sport'

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FACEBOOK: PANZER450

Hi guys,
This is what I was trying to explain above and I understand the confusion. My oil leak is NOT from the oil pressure line. It is from the speedometer cable.

Oh duh! :p the speedometer at one time had stuck, and someone put oil in there to lube it, and what happens, is as the cable rotates it acts like and auger moving the oil up the cable and thus it appears in the gauge housing, and the sealant is someone's attempt to do exactly what you want to do. I'd just wipe up what's there and then maybe check it again in a couple months.

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RIP: 80 300SD
RIP: 79 450SEL
2002 E430 4matic (212,000km)
2002 ML500 'sport'

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FACEBOOK: PANZER450

The only problem is its all over the inside of the housing between the clear plexi glass and the black backing that holds the instruments and the tabs on the bottom where the idiot lights are. It's in there to where I can't get to it. So how do I get it out? It looks like the clear plexi is permanently attached to the black housing.... Anyone got any ideas?

the gauge clusters can be completely disassembled. I've done it a few times, as long as you remember where everything it, and don't move any needles with your fingers, they may just get thrown out of whack. I used alcohol to clean the oil film from my gauges because it evaporates completely and is safe for the internals.

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RIP: 80 300SD
RIP: 79 450SEL
2002 E430 4matic (212,000km)
2002 ML500 'sport'

____________________________
FACEBOOK: PANZER450

I got everything apart except for the clear plexi glass which to me looks permanently attached to the black housing. Is there any way to seperate those two?