D7E Hyd Tank Cap

7H1447 is the correct hydraulic tank cap.

http://cgi.ebay.com/Caterpillar-Equipment-Hydraulic-Oil-Tank-Cap-7H1447_W0QQitemZ160387334582

That cap is still current Ryan. Now just make sure you get everything. The cap should have a ball bearing inside, then a metal disc and then a rubber washer to seal it plus hold disc and ball in place.
Later Bob

Thanks guys. I've bought a fair bit of parts off of Tornado heavy equipment before. Great bunch of guys. Always gone above and beyond to make me happy. That's where I got the shafts to rebuild my hyd steering clutch controll. I thought they were new but ended up being slightly used so they gave me half my money back.

I just wanted to make sure that was the correct one. Should have a chain or something on it so it doesn't go missing.

Does that ball act as a relief valve for the pressure in the tank?? My cap never did vent properly at all. When you screwed the cap off there was always pressure in the tank.

This kind of leads me to another question. How much oil should actually be in the tank?? Dip stick is long gone and no sight glass. I had it appart and tried to figure out where the suction line was and then filled it to where i though it was just past. Right now I've got it so it's just level with the bottom of the strainer. Sound right??

Thanks guys


Ryan

The hydraulic tank on your cat is a non vented system. It requires that the pressure build up to work properly. I just learned that recently.

There should be a stand pipe down into the tank so you can't overfill it. Try to top it up when the oil is hot or it wil blow out everytime you take the cap off.
Later Bob

The last time I put oil on it was basically at the bottom of the strainer. Thought I'd put another couple gallons in just to be on the safe side. Got about half a gallon in and it was running out the cap. When I changed the oil and filter I never bled off any air or anything like that. Just filled it to the screen and put it to work. Hasn't been any problems except for when it's cold outside. The pump or something in the tank howls when you lift the blade. I checked the rubber connector on the suction line and put new heavy duty bolt type clamps on but still does it. Once the oil is warmed up then it's all nice and quiet. You can feel it all the way back threw the tank.

Thanks ubucat, I wasn't aware of that. Do you know why it is??

Thanks

Ryan

Pressure in the tank helps the pump pick up oil and keep dirt out of the system. Let it idle untill oil warms up, the noise is likely pump cavitating with cold oil.
Later Bob

Thanks bob, it is 15/40 oil in the hyd. system and it does tend to get pretty thick in the winter. I've been leaving it in the float position and it seems to be better when i come back to the cat.

Would 10wt oil sufice for summer use in the hyd system?? Or would a good hyd oil be better??

Thanks

Ryan

Bob, when I was working yet #10 straight oil was all that was recommended by Cat in their hyd. systems the year round so is that the case yet today?