400D Part 2: More questions

Got the 400D home and in the shop! Still working on it to get it to run on diesel. Still starts easy on gas.

I"ve pulled the filter system apart and couldn"t find any obvious blockage but some parts were plenty dirty. Going to clean out the whole thing and replace both filters.

Also pulled the lift pump off and I don"t see anything obviously wrong or bad looking. Checked from above and the rack seems to move freely back and forth.

The oil in the pump seemed to have a some fuel contamination. I assume there"s some leakage from the lift pump. Looking at the lift pump it seems like it would be straightforward enough to change the seal. Any tricks or surprises in there? Anyone know the part number for the seal? I tried looking on the CIH website but with no luck for pump parts.

The oil in the pump was also fairly black, like crankcase oil. Any chance oil is leaking into the pump from the crankcase? I know that will involve pulling the pump to change. Part number for that seal?

Lastly, is there a way to make sure the plunger is not stuck without dismantling the entire pump?

I"m working from a blue ribbon service manual that covers the MD and an I&T manual that covers the same. Not exactly the same pump but will probably keep me out of trouble. I"m planning to order the right ones for the 400 soon.

The pump should have engine oil in it--no Diesel fuel. Most of them as time & leaky seals took their toll, ended up with Diesel leaking into the "crankcase" of the pump. Our 450D does this when shut down, so we just shut off the fuel at the tank when not in use. Have to get it worked on some time.

Yeah, this one has oil but it does have some dilution so I assume the seal is leaking. I have it all apart so might as well fix it.

The lift pump seals are easy and cheap. No reason no to do them.

you dont have to disassemble the whole pump to remove the plunger, but i would check a few things first. plunger is only stuck if the tractor is not getting fuel to the injectors and you have normal operation pressure on the gauge that is on the injector pump. if this gauge has no or little pressure it is a problem in the lines, filters, or transfer pump. If you still think the plunger is stuck it can be removed by removing the injector lines and the top cover on the pump then the internal high pressure line and plunger to follow. there is a special tooth to the rack gear so you cant install it wrong ad at this point you shouldnt be able to change any adjustments but the plunger can be worked to free from being stuck using something like carb cleaner. I did this last fall on our wd 9 and all is well now. I found the parts mostly copper seal washers and gaskets that I need from a pump shop as all the numbers were no longer available from Case IH.