C15 Severe Coolant Loss

Ok. I will take it out tomorrow. Just replace it, or should I be looking at it's condition?

 

Sulerhauler. I checked fuel pressure today. 75# @ idle. 75# @1800.
I will replace the pressure regulator valve and see what that does. I saw your reply to a fuel pressure issue back in 2013, where you mentioned an upgrade for the transfer pump. Would the upgrade be applicable here?
I have not capped off the output of the transfer pump and checked what the pump maximum pressure is yet.

 

Today's update. I replaced the check valve in the secondary filter base. Much better starting! I replaced the old spring in the fuel transfer pump. Pressure went from 75# to over 100#! I put a clear line it the return line from the back of the head. Nothing but fuel, no bubbles. I also changed the primary filter.
The engine seems to like the attention. It has better throttle response and pulls smoother.
Maximum boost pressure is still a bit on the low side, at 31#. When I drop the hammer, it zips right up to 31 and no more. The high pressure turbo still sounds like it has asthma. Not spooling up.
During the rebuild, I removed both stacks. I have just the one small muffler right now. There is not as much noise as I expected coming out. Does that one muffler work that well, or do I have an issue with the inards collapsing and causing restricted exhaust flow?
I could take the flex pipe off between the muffler and the turbo charger and see if that is the problem. That way the neighbors could let me know how the trucks sounds !

 

I will check the wastegate tomorrow. I know it moves, because I made sure is was freed up up when I did the rebuild.
I hadn't thought about putting air to it to watch it move. Great idea!

 

I got the injectors trim codes taken care of today at K&S Injectors in Wausau. They asked about what the issues that I had. The owner and his Caterpillar mechanic found a tear in one of the hump hoses, under one of the rings. I put air to the waste gate hose and it works very freely.
Boost still only goes to 31#, but the high pressure turbo spools up much better. I am going to remove the flex pipe and see if the muffler has any blockage.
I may have to drive it around for about a week and see if the neighbors can notice that it's running better!

 

I bought two 3 1/2" pvc caps. I drilled a 1/2" hole in the end of one and screwed in a male quick disconnect fitting for an air tool. I hose clamped one into the hump hose that goes into the head. The other plugged the hump hose just before the CAC. I set the pressure regulator on the compressor to 50 psi and pressurized the system. I left it sit for a while and the only leaks I could detect we're where I clamped the PVC plugs. I will get the soapy water spray bottle out and squirt connections with the idle turned up. Maybe I will find a couple more leaks. It sure would be nice to have a shop I could get out of the weather. We got a bit of snow today, just to remind us that winter is just around the corner