Hope everyone doesn't mind if I resurrect an old thread. Has anybody figured out a viable way to do this on the Mercedes canister-type filters? I also have a 300SD that I would like to add a bypass filter to. I do realize that the canister filter elements have minimal bypass filtration capability but I don't feel that it is doing as well as a separate bypass filter. I plan to use a single bypass element that ties into the pressurized side of the oil supply.
I have done this on other diesels and, I must say, the difference is amazing. I can change the oil on my Ford Superduty truck after 4,000 miles or so and the oil is still translucent. This wasn't the case before I put the filter on. Oil analysis also supports the better filtration. I use the Baldwin B164 bypass filter element on it and they are available easily for about $8 each. I usually replace both the bypass and the full-flow filter elements each time I change the oil but I have kept the bypass filter on through up to two oil changes. For the price, I really have no problem changing both filters every oil change and plan to do the same with the Mercedes.
Anyway, the Mercedes diesel is proving to be a bit of a challenge and I haven't heard of many people adding an aftermarket bypass system on it. The few that I have heard of seem to drill and tap the aluminum filter housing. I've considered that and may still do it. I'm also considering teeing off of the hose going into the oil cooler. One concern I have with doing that is that I don't know whether the oil going into the cooler is thermostatically controlled. I'm guessing that it is. Anyone know? If it is, then the bypass filter would only be working when the oil temp was high enough to open the thermostat valve going to the cooler. I would prefer that it have a constant source of pressurized oil. Does anyone else have info on an easily accessible, constant pressurized oil source on the early 80's era Mercedes diesels? I would appreciate any help I could get.