Bypass filter help please
 

I am interested in purchasing and installing a bypass filter on my 1999 E300D.

Where would the best place be to tap into the oil supply? Are there and capped and accessible oil galleries or perhaps a T into a oil pressure switch?

I figure that I will return the oil down the dipstick tube or through the oil filler cap.

I don`t know what your 99 E300D engine looks like or how the oil filter is mounted.
On the 617 engines I have seen some where the return line was tapped into the valve Cover, and the clean oil dumped onto the chain area.

Tapping into the oil cooler lines is one possibility, but there is only oil flow when the oil thermostat opens up.

I think I have seen where the oil filter lid was drilled and tapped to get the oil supply.

Charlie

On a 617.952 I drilled and tapped my Oil Filter Top/Lid 2 times. On for the Bypass Oil Filter Oil Supply and another for the Low Oil Pressure Alarm.
The only trick to it is you need to drill from the inside out in order to avoid any metal casting webs.
It drills and tapes easily with a 1/8" Pipe Tap and the correct drill.

For the return line you could drill and tap out the Plug on the Fuel Injection Pump that the Fuel Injection Pump Timing/Locking Tool, A&B Light goes into.
Just remove it; put it in a Vice and Drill and Tap it.

If your bypass system does not come with a restricted fitting you will need to make one. If you are making one I would use the Return Line fitting for that because Filter Oil will pass through it so it will not get plugged up.

Rough up the inside bore of the Brass Fitting, degrease it with Brake Cleaner and when dry fill it with JB Weld (used because it can take the temp).
Then consult your Filters Specs as to what size Drill you need. 1/16" or smaller has been suggested.

One of the pics shows the top of my Oil Filter and the other shows where the Plug is located on the Fuel Injection Pump Governor.