Trouble with hydraulics D8H

[Popsied]

My first attempt to post. My 8H sr 46A28063 does not have a sr tag on top of hydraulic tank. Missing when I bought machine. A friend has 46A28109 hydraulic tank number 60P4050. I have a new hydraulic pump on my machine but still have too much whining sound as if starving for oil. Also, I repacked tilt cylinder but when you hit a stump it tilts on its own. Valve must need packing. Question is. Is there a pickup screen in tank that could be covered. Does anyone have a diagram of what is in tank. My Cat dealer not very helpful.

 

[Old Magnet]

There is no pickup screen in the tank, just an open pipe pump suction. 59Pxxxx is a two valve hydraulic control, 60Pxxxx is a three valve.
There is a section of hose in the pump suction line. Make sure it is not leaking air or collapsing under pump suction pressure.
There is no packing the tilt control valve. There is a pressure relief valve that could malfunction or it may not be set to correct pressure.

 

[Nige]

If you can identify whether you have a 2 or 3-valve hydraulic control I'm sure someone can post up parts manual views of what's inside the tank.

 

[Popsied]

D8H hydraulics

Thanks for the help. My sn. 46A28063. Machine has blade with tilt and rear ripper. No serial number on hydraulic tank. Repacked the tilt cylinder but blade still will not hold its position. When you hang a stump on either side blade pulls down. Joe, my mechanic, wants a manual or help with settings etc before tearing into system. Any help appreciated.
Thanks

 

[Nige]

I'd stand corrected here but with blade lift, tilt, & a ripper that would indicate the need for a 3-function hydraulic control, ergo from post #2 above by Old Magnet a 60Pxxxx control would be the one on your tractor. With the Serial Number of the tractors being so close to one another it's not beyond the bounds of possibility that the S/N of the two hydraulic controls are not that far apart either.

Unless someone says different, I am of the opinion that you could use the manual from the 60P4050 hydraulic control from your friend's machine and it would suit yours as well. The tank of the 60Pxxxx hydraulic control was pretty much the same from 60P2422 to 60P4890, the last built. All I can see on-line is a Parts Manual, there is no "service manual" that would give D&A instructions and/or testing procedures. Hopefully another member might have some info in that regard.

 

[ETMF 58 White]

My 48A D7E is probably the same vintage as your D8. My hydraulics were recently getting very slow and would not hold the blade up. I opened up the tank window to see what was in there and decided that I didn't have the time or inclination to fish that big open valve conglomeration out of there to rebuild it. Took it to ITR shop and they had an old timer who knew how to work on it. Rebuilt the valve and put a new hydraulic pump on it and now it works fine-- well, as fine as a slow, low pressure, antiquated hydraulic system is going to work. Most of the cost of the repair was labor. The new pump and the various seals were way less than a grand. Of course, I also was out most of a new barrel of 30 wt oil.
Moral of the story: these old tractors are tough, but not very efficient to work on.

 

[Old Magnet]

That's a fairly involved unit to work on. I'd suggest you get these manuals (ebay) about $15 for the parts manual, $45 for the Service Manual'
Here is what you need to get and some pages from the Service Manual. Let the fun begin.

 

[RBMcCloskey]

My 48A D7E is probably the same vintage as your D8. My hydraulics were recently getting very slow and would not hold the blade up. I opened up the tank window to see what was in there and decided that I didn't have the time or inclination to fish that big open valve conglomeration out of there to rebuild it. Took it to ITR shop and they had an old timer who knew how to work on it. Rebuilt the valve and put a new hydraulic pump on it and now it works fine-- well, as fine as a slow, low pressure, antiquated hydraulic system is going to work. Most of the cost of the repair was labor. The new pump and the various seals were way less than a grand. Of course, I also was out most of a new barrel of 30 wt oil.
Moral of the story: these old tractors are tough, but not very efficient to work on.

I think 10w Series 3 engine oil is what should be used in the hydraulic system, 30w is too heavy and will effect performance.

 

[Old Magnet]

You are correct, SAE 10W is recommended for above 32 deg. F. down to -10 deg. F. and lower. Lighter oil for extremely low temperatures.
ISO 32 hydraulic oil would also be acceptable.

 

[Popsied]

Thanks for the help.

That's a fairly involved unit to work on. I'd suggest you get these manuals (ebay) about $15 for the parts manual, $45 for the Service Manual'
Here is what you need to get and some pages from the Service Manual. Let the fun begin.

I ordered both. Thanks for the help. If you don't understand all the Cat lingo I didn't know which books to order. Service manual 183 means nothing to me. Where does 183 come from. Also Cat parts man told us to run Delo 30wt in hydraulics. I'm in East Texas, always above 20 degrees most likely in the 80-105 range. Should I be running 10 wt.
thanks for all help
Elliott

 

[Nige]

In Cat machines, even in tropical climates, all I've ever run in Cat Hydraulic Systems is 10W or ISO 32 which is the equivalent.

Regarding the hydraulic control, that goes back to the days when hydraulics were new and not every tractor was fitted with one. The middle number usually indicated the tractor model on which the control was installed, hence a 163 would be on a D6, a 183 on a D8, etc. So the hydraulic control has its own Serial Number (separate to the tractor) which is the one marked on the hydraulic tank. Unless your tractor has had the tank replaced at some point I would suspect that the S/N might be there stamped on the tank but hidden under years of paint.

 

[Old Magnet]

Yes, the Hydraulic System numbering takes a little getting used to. Eg: the 183. I don't really know the significance of the 1 but as Nige states the second number applies to the tractor model designation then a 1, 2, or 3 designates the number of control valves in the unit. Beyond that is the unit Serial Number which you need to know to get correct parts. On your unit the s/n should be located on a tag on top of the tank right next to the filter access.

If you haven't noticed the Service Manual does not match the 59P/60P serial numbers. I have never seen a service manual that matches those numbers but using the
27H1-up, 28H1-up manual for earlier units works as far as service information. Using the 59P/60P parts manual for any purchases should keep you out of trouble.

 

[ETMF 58 White]

You are correct, SAE 10W is recommended for above 32 deg. F. down to -10 deg. F. and lower. Lighter oil for extremely low temperatures.
ISO 32 hydraulic oil would also be acceptable.

Well that makes sense. I used 30w because, well, that's what my dad and uncle always used in this tractor since he bought it new. Same in the engine and transmission. That said, there is a world of difference in the speed of this hydraulic system and my newer high track Cat and hydrostatic JD. When I change it again, say in about 10 years, I'll use 10W. In the meantime I'll just keep using it as a spare dozer when some dirt needs bulking. Have to run it myself or get my 70 yr old part-timer to run it as the young guys aren't worth a dime on it and don't wanna be.