"jfredn7" wrote:

I have a similar problem. I have a D6 which I think is about 1954/ I have the serial number somewhere, but not at hand.

My problem is that the pump does not seem to be pumping. To get the blade to lift, I have to hold the control in the UP position for a long time and it inches up slowly. I do not have any user manual or drawing or picture of the hydraulic system, which makes it hard to know what to do on it.

I assumed that the tank in front was the hydraulic reservoir, and I checked it and it is full of oil, so I assume it is not a lack of hydraulic oil that is keeping it from lifting the blade. It worked fine before.

So, I assume that for some reason that the pump is not pumping like it should be. So, what is my next step? Should I remove the pump and reservoir as was done above. If so, what do I do then? Can the pump be rebuilt? Are used replacements available? I would appreciate any help on this. Otherwise the tractor runs great.

jim nicholson

Does the blade stay in position when you let go of the lever.? Just want to make sure that you do not have a cylinder bypassing before you tear the pump apart.

Having a similar problem. There are 2 bolts on the bottom ears on each side. is that all I need to undo for it to slide forward or do I need to open up the tank? Obvious hose removal on top

you need to disassemble the drive coupling from the front pulley on the engine. unhook the plumbing and bolts then remove as a unit.

Turns out I did buy a service manual but does not detail the hydraulic pump. Go figure!

As for your comments about removal at the pulley, there looks to be about 8 bolts there, but there is no way it could slide forward with the radiator still on the machine.....am I missing something? I would have thought that the pulley had some splined shaft to the hydraulic pump and they would just slide apart. There are 4 nuts I can see that look to attach the tank assembly close to where the shaft would be. I can post pics if needed.

just hang on for someone who has more experience to chime in. i haven't taken one down as of yet and am sure there are better than me to advise.

Yes the pump is splined just outside the tank. Remove the four nuts and the outer support brackets and control unit will slide off.

budasterisk;240721 wrote:

Turns out I did buy a service manual but does not detail the hydraulic pump. Go figure!

Nothing to do with luck. Cat had a book for each attachment. So hydraulics are different books than dozer blades even if used on the same machine.