I have a Cat 951C great old machine use it quite a bit around the farm. I was scraping some dirt the other day and got up against a tree stump no big deal normally, I started lifting some and my hydraulics quit and I could hear the pump whining. I shut it down for the day. Returned the following day and found my hydraulic fluid was low I filled reservoir and fired up the machine bucket lifted no problem. Scrapped another load of fill into bucket and when I tried to lift it hydraulics quit again and I could here the pump whining. I shut it down and went and did some other work around the farm. Ok back today unloaded dirt from bucket with tractor. Fired up 951C no hydraulics at all noticed low pressure lines where there is a hose coupled between hard lines seems to be leaking hydraulic fluid some at least. Heading back out to that farm shortly will check filter. Is it possible I have gotten air sucked into pump from running low on fluid and need to somehow bleed it?? I assume the whining was pump cavitation do to low fluid pressure from plugged filter or air in system. Got to get the old girl working again I’ve got a low water crossing to repair and then move the machine to a different farm. I could use some assistance gentleman. Also I tried to lift the bucket on the 951 with the tractor to be able to put the ram lock on the lift cylinder but couldn’t even move it. Any ideas on how to do that if I have to replace the pump cartridge?
My SN is 86J2868 Arrangement 1V3082
Did you put the lift lever in float? All the way forward past the holding detent. I'm not sure on this one, but on mine the shaft that turns the pump is driven with splines. They can strip off. It will whine if it gets low but should of bin ok after filling. Could be air, that one seems puzzling. I don't think there's a pickup screen, that could choke things off if plugged, pulling the filter maybe next.
In pulling the filter you want to cut it open to look for metal debris to figure on next steps. I take a section of pleats and squeeze out the oil with a bench vise, much easier to look at then.
The filter seemed Ok but I didn’t cut it apart it has a steel shroud over the pleats so cutting it will be a chore. On the right side of the engine at the rear looks like a starter at the front it looks like the alternator is the hydraulic pump under the alternator?
Looking at my manual the one photo that shows the pump now I think it’s on the left side of the machine. I have got to get the loader out of the way so I can see what I’m doing on this machine.
My machines have safety keepers for when the bucket is up. You need to have a safe way to keep the bucket up if its in your way. Use a cut off wheel in a 4 1/2" grinder for the filter cage. It will help to know if there's a "for sure" mechanical problem.
Look for a major hyd. leak. It may be contained in your belly pan. A belly pan full of dirt will hold a lot of hyd. fluid. Low fluid isn't an instant thing unless you have a major leak somewhere.
I have a safety keeper for the lift rams. Two years ago I had to replace most of my high pressure injection lines that pretty much required the bucket to be in the air or at least made it easier without it in the way. Within about 6 months of buying the old machine several of the injection lines cracked.
The hydraulic pump is on the near side front of the engine, its a Vickers 19 gpm cartridge, it sounds like you have a supply line to the pump fault, the pump bolts in with 2 15/16" head size bolts, to lift the loader frame without power put the lift lever all the way forward into float position, the safety support should be clamped in it's store position under the rear of the fuel tank . tctractors
Thank for the reply is the “near side” a typo or is that some sort of heavy equipment terminology I’m unfamiliar with? When I get time I’ll start tearing into it, to many irons in the fire here lately. I have a pallet of barbed wire being delivered tomorrow lots of fence to build so I need the 951 running.
"Near Side" front = LH side front.
I'm puzzled on the terms near side and (far side ?). I'm pretty sure the pump has external pluming that can be traced back to the tank and controls. tc sounds on the money...... something seems wrong with the intake circuit of the pump. To lose all intake oil capacity to me doesn't sound like air leaking into the line...... it sounds like blockage. Open up the oil filter pleats to see if oil pump guts are failing. Then I would eyeball the line. Then think do I have to drain the tank to check the line from tank to pump? You may have to drain the tank to change cartridge anyway.
If the reservoir was full and there's no external leaks it has to be a blockage, serious air leak (although that would probably cause external leaks) or the pump is shot. Maybe a pump drive issue but that shouldn't cause the pump to whine like it's cavitating. Could the sound be something in the pump drive spinning and not turning the pump? I would have thought a 951C would have a bigger pump than 19 GPM. That's only a couple GPM more than the standard pump on a much smaller 931.
Near side and off side to be correct, but only if you drive a car with the steering wheel on the right......... Near side - kerb (curb) side. Off side - centre of the road side.
Thanks Nige! Good to know terms from both sides of the Pond.
First I must thank Nige for his bit of script to sort the steering wheel thing out as I never put a thought into the left right thing, well the pump on a 951C is if I recall a 19 U.K. Gallon pump, a D4D has a 21 Gallon pump it must be the need for speed, on the C series there is 2 transmission oil coolers 1 water and 1 air blown with a temp' regulator controlling things, the oil feed to the pump is unfiltered from the tank other than the oil pick-up pipe is a few inches off the tank bottom, the pipe then travels down to the hydraulic pump via a selection of pipe work, there is a rubber hose inside the tank to link the oil return filter that if damaged can froth up the oil and cause carnage needing the tank to be split open to check, I would think a puddle of oil on the floor would tell plenty??? tctractors
Well took a spin by the farm found the pump mounting bolt laying on top the pump. Oh boy wonder what sort of damage this little incident has caused possibly the pump has rotated some IDK I don’t have my manual with me to see how many mounting bolts hold that pump to the engine. If it’s just two then maybe this thing has rotated enough to disengage the spline’s.
Both bolts fell out put them back in all is well.
My little operator helped me get the crawler fixed this evening. He operates it on occasion usually just driving it from spot to spot around the farm or I have him run it if we are skidding out logs with it.
Start them young! He'll learn more from dad right now than any other teacher! And will learn things like safety if you encourage it- so it won't be an alien concept when he hits the working world. Being on a farm, I'm sure you're teaching a lot of other things, too! And buy a lottery ticket-- the problem with the Cat cost you a couple of bucks in bolts but could have been thousands. Feelin' lucky or what?! Jon.
Might be a good idea to check if the splines/pump drive have any damage before you put the machine to work. Something may have caused the bolts to come loose too. Better to investigate now than have a bigger problem down the road.
Interesting pump, plumbing must not be attached to this spinning apparatus you managed to catch and bolt back down before reaching escape velocity! Pick up a couple lottery tickets for me! Dave has a good thought, could be something in that pump that shook those bolts loose. I'd be interested in a picture of this tuff bugger.