oil pressure guage leak - PeachParts Mercedes-Benz Forum

mattc · #1 08-10-2014, 03:26 PM

82 300D - oil pressure gauge is leaking. From what I've read in the archives: it needs to be replaced, and the best method is to either replace the entire cluster, or, at least the section with the oil press. gauge/temp. gauge/fuel gauge. I am thinking the best would be simply replace the part of the gauge I need - in order to avoid any possible speedometer issues. I understand (correct or not?) that the replacement would have to be from an 82-83-84 or 85. With the exception the 85 speedometer wouldn't work correctly, if I decided to use the entire cluster. I checked the inventory at the local parts yard, and it appears the only likely candidate is and 83 SD. So, my question is: will the SD cluster (or at least the part of it I really need) be compatible with the D that I have?
Any other ideas/suggestions, regarding this matter, would be welcome and appreciated.
And YES, I am aware that 2 wrenches (10mm & 13mm) are the prescribed way to loosen/tighten the oil line, to reduce the chance of leaks.
THANKS IN ADVANCE Matt

ROLLGUY · #2 08-10-2014, 03:43 PM

Quote:

Originally Posted by mattc

82 300D - oil pressure gauge is leaking. From what I've read in the archives: it needs to be replaced, and the best method is to either replace the entire cluster, or, at least the section with the oil press. gauge/temp. gauge/fuel gauge. I am thinking the best would be simply replace the part of the gauge I need - in order to avoid any possible speedometer issues. I understand (correct or not?) that the replacement would have to be from an 82-83-84 or 85. With the exception the 85 speedometer wouldn't work correctly, if I decided to use the entire cluster. I checked the inventory at the local parts yard, and it appears the only likely candidate is and 83 SD. So, my question is: will the SD cluster (or at least the part of it I really need) be compatible with the D that I have?
Any other ideas/suggestions, regarding this matter, would be welcome and appreciated.
And YES, I am aware that 2 wrenches (10mm & 13mm) are the prescribed way to loosen/tighten the oil line, to reduce the chance of leaks.
THANKS IN ADVANCE Matt

I have not tried it, but I assume that you will need a 123 gauge, and the 126 will not work. It is best just to replace the section that is bad, especially if everything else works (speedometer/odometer, clock, tach etc.). It is impossible just to replace the oil pressure gauge only on the circuit board, you will have to swap the entire board with a known good one. While you have all 3 out, a good idea is to paint the needles (fluorescent orange) and the inside of the instrument light wells (white).......Rich

toomany MBZ · #3 08-10-2014, 03:50 PM

R…G… is correct, a 126 oil pressure gauge will not work with a 123, in this case anyway.

The top cluster is from a 123, red circle, the bottom is a 126, green circle.

The 123 used a mechanical OP gauge, the 126 is electric.

tangofox007 · #4 08-10-2014, 03:56 PM

If you want to send me the fuel/temp/oil pressure gauge portion of your cluster, I will install a good, used oil gauge for you. PM me if you are interested.

mattc · #5 08-10-2014, 03:57 PM

Thanks for the speedy replies. The yard with the SD is a bit of a drive, was trying to save myself a useless trip. I guess I would have found out the news you gave me when I got there - but, thanks to you both, I will look elsewhere. As far as possible candidates: am I correct (do you know?) that I will be looking for an 82 -85 D only for that part? Thanks Again, Matt

ROLLGUY · #6 08-10-2014, 04:22 PM

Quote:

Originally Posted by mattc

Thanks for the speedy replies. The yard with the SD is a bit of a drive, was trying to save myself a useless trip. I guess I would have found out the news you gave me when I got there - but, thanks to you both, I will look elsewhere. As far as possible candidates: am I correct (do you know?) that I will be looking for an 82 -85 D only for that part? Thanks Again, Matt

I could be wrong (please correct me if that is the case), but any diesel 123 gauge section should work as long as it has the same configuration. I think the exception might be a 240, as something I remember is different. You could maybe even go back to 1978? The best way that I know of to tell the difference is where the round wiring connection is. If the replacement is in the same spot on the board, it should work.....Rich

llensart · #7 08-10-2014, 06:53 PM

Quote:

Originally Posted by ROLLGUY

I could be wrong (please correct me if that is the case), but any diesel 123 gauge section should work as long as it has the same configuration. I think the exception might be a 240, as something I remember is different. You could maybe even go back to 1978? The best way that I know of to tell the difference is where the round wiring connection is. If the replacement is in the same spot on the board, it should work.....Rich

I changed the Oil Temp Fuel cluster from a 82 300d to my 81 240 D works just fine

mattc · #8 08-10-2014, 08:08 PM

I guess, from what I'm reading, that I have more vehicle choices from which to pull this part from than I thought. Thanks all for the information. I'll look around for what I need locally... ...if no luck, I might be putting in a 'parts request' here. I've got a few options locally; even saw one on E-BAY for $45.00 But I think I'll hold off on that one for now. Hope to pick up the part around here on Monday, and be rolling by Monday evening.
Thanks for the help. Matt

toomany MBZ · #9 08-10-2014, 10:02 PM

Yeah, any 123 oil pressure gauge should work, turbo or not. Four cylinder or five.

tangofox007 · #10 08-10-2014, 10:33 PM

Quote:

Originally Posted by toomany MBZ

Yeah, any 123 oil pressure gauge should work, turbo or not. Four cylinder or five.

The pressure mechanism itself will work. Even W115 units can be used with a little modification to the mounting aspect. The cluster segment, however, is not the same across all W123 models.

Replacing the pressure mechanism is not difficult, provided that you have the means to remove the needle and calibrate same when installing.

ROLLGUY · #11 08-11-2014, 11:09 AM

Quote:

Originally Posted by tangofox007

The pressure mechanism itself will work. Even W115 units can be used with a little modification to the mounting aspect. The cluster segment, however, is not the same across all W123 models.

Replacing the pressure mechanism is not difficult, provided that you have the means to remove the needle and calibrate same when installing.

Therein lies the problem for most of us. I believe there is also some rivets involved. It is much easier to replace the entire unit.

charmalu · #12 08-11-2014, 11:15 AM

Quote:

Originally Posted by llensart

I changed the Oil Temp Fuel cluster from a 82 300d to my 81 240 D works just fine

I installed a fuel/oil/temp gauge from a 79 or older W123 into our 85 300D. Did it because I wanted the "F" Temp and PSI for the Oil pressure.
Works just fine. Also installed one into our 80 240D, think it was the first year for the "C" temp and Bar for the oil.

The price for one from PNP is around $16 + for the gauge. the whole cluster maybe $45. A gauge from a Gasser like a 280E/CE will work, but then it has the Vacuum gauge in it at the bottom.

Charlie

mattc · #13 08-11-2014, 12:45 PM

Picked up the part I needed from a local guy this morning; and will install it this afternoon. Not sure what year it came off of, because it was in a cluster, on the shelf. The guy took off what I needed, charged me $25.00, and I was on my way. We talked old benzs for a good while (he had a bunch of them) and then a fellow pulled up who had a 70 chevy C 10 pickup truck, like I was driving - so the 3 of us stood around for another 40 minutes talking old chevys. Made 2 new friends, got my part, and have a new parts source. Good day!!! Thanks to all for the help. Matt

toomany MBZ · #14 08-11-2014, 03:29 PM

Cool deal.