D-3 Caterpillar engine oil leak

Projacktech · Jun 19, 2014

I have a D-3 Cat Dozer with an oil leak just under the Injection pump. I can't see exactly where it's coming from but it's a pretty bad leak(almost a steady stream). I don't have any manuals and this is my first Caterpillar machine. I read a reply post not long ago by BOB in Ontario ( I think that's his name)
He was telling someone to watch for a cracked Injection pump gear housing on the 3204 engine (79U). My machine is a 1974, best I can tell. Is there a specific problem area to look for on this? I am afraid to remove the pump before I know exactly where the leak is coming from. There is some kind of small steel line with an elbow just underneath the pump, coming from the block. It looks like it may be an oil line coming from or going to the Injection pump and the leak looks like its comings from this area. Any idea's would be appreciated, thanks

Anonymous-0 · Jun 20, 2014

If you have an early machine with the old scroll fuel pump they had the rear support come loose and then the load on the pump mounting would crack it. Wash off the drive housing and look for a crack on the under side. It's not a big job but you should have a timing fixture to assemble it. If you can't borrow one you could wing it. Remove the pump and set the engine at #1 TDC and observe the orientation of the of the off set drive tang. I think you will find it's vertical and off set to the outside but might be wrong.
Later Bob

Projacktech · Jun 20, 2014

Thanks Bob,
I assume the housing needs replacing which means tearing down the front of engine? Also, are the housings hard to find used?

Anonymous-0 · Jun 21, 2014

There is a cover to get the gear off of the shaft. Gear is mounted on a taper. If you buy used look it over real good for cracks in same area. Pump support is not strong enough and comes loose then housing breaks.
Later Bob

Dr. Walt · Jun 28, 2014

FIRST, before assuming that you have a cracked injection pump housing; take some Brake-Kleen or any other spray solvent and thoroughly clean the area under the pump, especially the area where that Elbow-fitting & steel line are. Check to make sure the fitting on the steel line where it connects to the elbow-fitting is tight. Make sure the elbow-fitting is tight in the pump housing; and inspect for hairline fractures in the steel line - especially where it goes into the connector to the elbow. - THEN, if everything appears to be good, have someone else start the machine while YOU WATCH under the pump, this should tell you where your leak is.

Doc

D-3 Caterpillar engine oil leak

Projacktech

New User

Anonymous-0

Well-known Member

Projacktech

New User

Anonymous-0

Well-known Member

Dr. Walt

Well-known Member

Similar threads