Caterpillar D4D 78A 7128

[Hollyrock]

Good morning,

Looking for some advice, i recently purchased a Caterpillar D4D 78A that had been sitting for about 7 years. Got it home put 2 battery's in it a shot of ether and she fired right up, was quite amazed. It now seems that i have fuel in the engine oil as the dipstick is way high, any advice on this?

Bryan

 

[Mcrafty1]

The oil is to be checked with the engine running at low idle, I believe....at least most of the older Cat engines are that way. If you are checking it with the engine off it'll be a ways above full mark.

 

[Hollyrock]

Hi Mcrafdty, i have at Cat 3304 the dipstick says to check the engine oil while idling. The cat d330 engine dipstick says nothing, maybe it was changed to a blank one.

Bryan

 

[Mcrafty1]

Hi Mcrafdty, i have at Cat 3304 the dipstick says to check the engine oil while idling. The cat d330 engine dipstick says nothing, maybe it was changed to a blank one.

Bryan

Not sure, I have a D333a in my D6C and that say check with engine at low idle. many other Cats I've owned or been around all we check when idling. Some of those in the know here will be along and confirm or deny.

 

[Dave Neubert]

check when idling most dip sticks have 2 sides one safeto start and check when idling

 

[Hollyrock]

Yep all good advice but i have confirmed there is diesel fuel in the engine oil.

 

[Old Magnet]

Not many places for fuel to get into the crankcase. Possible leakage through
transfer pump seals but the tell tale drain line between seals would have to be plugged for that to happen. Other candidate would be past the injection pumps which isn't very common. A failed injector can also over fuel a cylinder with fuel winding up in the crankcase.

 

[Hollyrock]

Hello all again,
yep you were right Old Magnet, the weep hole on the fuel transfer pump was plugged. We had it apart to see that. We rebuilt the pump with a new shaft and seals/gasket. The shaft was wore down, looked like it was subject to water at times as it was corroded. Now there is no diesel fuel in the engine oil. And, yes for sure need to check the engine oil with running, even though the dipstick says nothing.

Thanks all!!

Bryan