About six months ago, I purchased a 91 300TE 4-matic wagon. Recently, the 4-matic light came on. Information as to what might cause this light to illuminate seems to be sparse. My owner's manual mostly says to "see your dealer" ... which, as best I can tell translates as "Open your wallet".

I found the hydraulic fluid reservoir, and I believe it is low, but I don't see any graduations to indicate how full it should be.

Any information is appreciated.

Thanks in advance,

LeonH

There should be a dipstick in the top of the reservoir....keep it high, there's no reason not to.

If this is the cause of the fault, (low hyd. oil) you have to take a battery lead off for a few minutes to clear the fault code.

How many miles are on your 4matic? This series vehicle, 1990-1993 anyway, had a problem with the transfer case failing almost like clockwork around the 130,000 mile mark. The 4matic light came on and stayed on in my '92 300TE 4matic at 133,000 and this was the cause. But, because of my love/hate relationship with this car, (love it when it works, hate it when it needs a frequent repair) I paid an independent mechanic $2,500 to replace it. It turned out the left front ABS wheel sensor was also bad, which might also be the cause of the light being on, but likely then it's be your ABS light. But now, with the new transfer case, the wagon once again goes like a tank through snow, slush and ice, especially with the 4 Nokian NRW's, (now called WR's). Better than any SUV for sure!

As for the 4matic fluid, Ottobun is riight, there is a dipstick on the lid. It is vital that the level be full. If it drops, this is a symptom of a bad transfer case and could also be the cause of the light. Oh, and be sure to use only the MB 4matic fluid. Like MB anti-freeze coolant, it's more expensive, but a small price to pay to keep the repair gremlins away. Good luck.

1962 MB 220SEb Sedan
1992 300TE4Matic Wagon
1995 Subaru AWD Wagon

Sometimes, I'm told, even as the oil level in the reservoir goes down slowly, it's not completely awful ($$$) news: there's two hydraulic lines from the reservoir (one in / one out) to the transfer case and it could be a small external leak in one of those or their union at the TC, fairly simple repair.

Also, even if the leak is internal, it's not necessarily death for the system: change the ATF fluid part in the late fall which will purge any hyd. oil contaminating it, use it in the snowy months, and then turn off the system when the winter weather is past (flip the test lever up). Unless the system's internal seals are totally shot, the inter-chamber leakage can be so slight that the thing works well...remember the TC is engaged only about 1% (or less) of the time, even in winter.

I've done this for 5 years and have no problems with system, and now that the roads are crappy, I'm pretty happy to have it in good order.

Actually, (pardon my correction Ottobun), but the 4matic system is always engaged from a stop to about ten miles per hour. It is designed this way. If no wheel slippage is detected, the sytem automatically disengages. If you do a search here on "4matic", about a year ago there was a posting with a link to a very thorough explaiation of the system which is very helpful in understanding not only how it works, but why it works so well. Second, though Ottobun disengages his 4matic with no adverse affects, it is my understanding that when you do this, it also disengages the self leveling suspension pump, which will affect the vehicle's handling. However, as he said, unless the leak is major, you can drive for many miles before a TC replacement is required.