MasterTech

Sounds like a possible data link issue. Is the fault light (lightening bolt) on?

Here's some info on the Kingpins, hopefully it will help.

Kingpin.pdf

This is not a bad job, The cotter pins need to be removed then the bottom cap screw out. Rear trunions can be a bear to get off. Got ahead and cut the u-bolts off the the hot wrench. you'll need to torque the new ones to about 1600 ft. pounds. Maybe it will have a 2-piece cap, there a lot easier to get off. Good luck!

here's the specs, hope it helps

AIR.pdf

Prob. be the fastest and easiest way to remove them, one that old isn't gonna give up to easy. I always use the hot wrench to remove the one piece units.

It is a oil drain rail it's used to supply oil to the bearings, it's very important.

you need to check the blink code with the cruise switch it will give ya a blink code #'s for the active fault(s)

The first place I would look if there's no external leaks is the egr cooler, we have had a lot of issues with them on the MP series engines. Take the exhaust outlet hose loose (on the pass.side near the front of the egr cooler) and check for coolant inside.