Did a search and could not find any info on the topic. I am in the process of removing the oil filter housing on my 87 300SDL and while fiddling around with removing the bolts for that, I noticed the connection between the fuel warmer and the head seeps a little coolant when I wiggle it. Since the fuel thermostat was removed long ago for my veggie conversion, I want to eliminate that connection completely and just put a simple fitting on the head to connect the heater hose to. So, does anybody know what the thread size is for the head connection there? If I remember right from last night, it seemed like there was a bushing screwed into the head, and then another fitting screwed into that bushing. That fitting was where the fuel heat exchanger connected to. Thread size of either the head, or that bushing would be of great interest to me.

On a side note, in case I don't end up totally removing the heat exchanger, any ideas as to the type of connection this is. I assume it is just sort of a plug-in type connection with an o-ring but if anybody is more familiar with it I would love to hear what I am going to find when I take it apart so I can have the proper repair parts ready. Sorry for the long post and thanks in advance for any help.

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ASE Master Mechanic
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Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
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1985 300SD
1983 300D
1984 190D
2003 Volvo V70
2002 Honda Civic

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