Hello all. Went to check the oil level in the housing and upon unscrewing the cap oil gushed out the filler. Smelled the oil and it has the smell of diesel. I guess the seal on the pump is bad allowing diesel in the oil. Question ... can I drain the oil/ diesel out and refill with fresh oil to finish doing a fire trail. Will be used for about 5-6 hours. I don’t want to blow the pump up. Thanks for any advice. 👍👍👍

I would look carefully at the drain lines that are fastened at the left front corner of the engine block. There are usually two there and one will have a drain line from the injection pump housing teed into it. Most likely that line is crushed or crimped somewhere along its path to the bottom of the block.

I don’t think it’s very likely that you have gotten much diesel into the engine oil but that is the big concern. You may very well just be experiencing normal leakage rates from the injection pumps that has accumulated because the drain was blocked. In that case draining and refilling the injection pump housing and governor and refilling with fresh oil Might get you by in good shape. But fixing the blocked drain should fix it up correctly/permanently.

The usual leakage route that severely dilutes the engine oil is an o-ring between the injection pump housing and the filter tower it is bolted to. I’ve never heard that that seal leaking has caused the diesel to accumulate in the injection pump housing but keep a close check on the engine oil level and condition because if that gets diluted, the failure is frequently catastrophic $$$$!