Cat 955L hydraulic pump question

Was just looking at a 955L, real clean machine in decent condition and cared for but the hydraulics when running the bucket sound terrible, like its pumping mud or concrete or something. I'm new to this machine but I'm assuming this is a bad sign. They had mentioned they had topped it up with hydro fluid, but I raised/lowered it a bunch to bleed it and it didn't help. When I pop the hyd tank cap off it hisses like its got compressed air in it (checked this each time after I ran it). How hard is it to replace the pumps in these machines? Do you have to pull the whole cab and top end off? When I use the word "hard" here I'm talking about time, is it a 1 day job, 2 week job, etc.

Can you drop the schematic pls?

Schematic of what? I don't have a service manual because I don't own this machine. I'm assuming it's a Vickers style vane pump where you can swap out the cartridge, but I just want to know how much labor is involved.

I don't remember that being a real bad job

Lumberjack Matt said: I'm assuming it's a Vickers style vane pump where you can swap out the cartridge, but I just want to know how much labor is involved. Click to expand... If you have the machine Serial Number I can look up the pump and whatever parts might be available for it. TBH I doubt it's a Vickers pump, but that is TBC.

I knew I was forgetting something... 71J4277 This is showing up for me as a 955K on the Cat website, but the side panels say 955L. They must have swapped out the hydro tank or something off a newer machine.

From what I'm reading 71J is a prefix for a machine built in Japan? I believe it has the D330 engine although it was so covered up it was hard to verify. If the side panel doesn't match the S/N it could be a frankenstein repair from several different machines. It appears to have factory ROPS on it, which I don't think the K did so maybe thats what this is? Getting more confused the more I read.

Lumberjack Matt said: From what I'm reading 71J is a prefix for a machine built in Japan? Click to expand... It was built in Japan. It is the equivalent of a US-built 85J-prefix machine. In the same way as the 85J machine production started as a K model with a D330 engine and switched to being an L model with a 3304 engine during the course of the production run. As near as I can tell the engine and model change (from K to L) happened at Serial Number 71J4558 and the 3304 engine used from there onwards was a 43V-prefix. So provided the engine in your tractor is original it sems most likely to be a D330.

Thanks for the info Nige, I always appreciate your help. I wish I had spent the time to grab the engine tag to know for sure, but I suppose it is possible that it is actually an L model as the S/N is within a few hundred numbers. I guess the main question still remains though as to how much labor is involved to replace the hydraulic pump. I think this machine is pretty cheap given how good of condition everything else is on it, especially the UC, but I don't want to add a huge new project to my plate. I can probably get it for around $6-7k.

Answered my own question I think, was poking around on jensales website and the sample of the manual for the 955L by pure providence includes the page on removing the pump...looks like it's running off the crank pulley...shouldn't be too hard.

I believe you will find it mounted to torque housing

That sure would make a lot more sense

I wouldn’t trust Jensales manuals as far as I could throw them. Just sayin’

Lumberjack Matt said: I suppose it is possible that it is actually an L model as the S/N is within a few hundred numbers. Click to expand... Highly unlikely seeing as there are two Parts Manuals, one with 955K on the cover and the other with 955L. The S/N ranges are 71J1-4557 on the former and 71J4558-Up on the latter. Someone's been playing sticker bingo.... Attached the instructions for R&I of the hydraulic pump. This was not from your machine but was as near as I could get.

Nige said: Highly unlikely seeing as there are two Parts Manuals, one with 955K on the cover and the other with 955L. The S/N ranges are 71J1-4557 on the former and 71J4558-Up on the latter. Someone's been playing sticker bingo.... Attached the instructions for R&I of the hydraulic pump. This was not from your machine but was as near as I could get. Click to expand... Now that I think about it, this makes more sense as the bad pump noise seemed to be coming from underneath the seat rather than the engine compartment. Either way it looks like a simple job that wont require pulling the ROPS off. The machine will be here next week so the first thing I'll be doing is getting the engine s/n to make sure its a D330 before I buy a parts and shop manual.

Lumberjack Matt said: The machine will be here next week so the first thing I'll be doing is getting the engine s/n to make sure its a D330 before I buy a parts and shop manual. Click to expand... For your Serial Number. Parts Manual is Cat publication reference UMX00085 covering 71J1-4557. Service Manual is REG00634. Here is a copy for sale on eBay where it states that the publication covers machines 71J2178-Up.

Nige said: For your Serial Number. Parts Manual is Cat publication reference UMX00085 covering 71J1-4557. Service Manual is REG00634. Here is a copy for sale on eBay where it states that the publication covers machines 71J2178-Up. Click to expand... The machine finally arrived, I was able to get a probe past the panels and see that the serial number tag on the engine matches the one in the cab, but that's really no help. Is there another tag on the engine or way to identify if it's a 330 or 3304? The only parts book floating around on ebay only coveres serial numbers up to 71J39XX. I ordered one off servicemanualpro, but its not coming or they can't find it. The service manual I bought says it covers 71J1-5831 along with 57J/64J/85J, but it only has the D3304 engine covered in it.

What does the valve cover look like?

Lumberjack Matt said: the serial number tag on the engine matches the one in the cab, but that's really no help. Is there another tag on the engine or way to identify if it's a 330 or 3304? Click to expand... If the Serial Number on the engine is the same as the machine (i.e. 71J4277) then the engine is a D330C. If it was a 3304 the engine Serial Number would be 45Vxxxxx. The change from D-series engines to 3300-series was the time at which engines got their own separate Serial Numbers instead of carrying the machine S/N.

Thanks Nige! The simplest explanation would seem to be that they just threw the 955L decals on after repainting it at some point. It was really hard finding a newer version of publication UMX00085 that covers my serial number, hopefully the one that's coming from ServiceManualPro will do the job. The Cat website is no real help, it doesn't even recognize the serial number. Kind of cool seeing "made in Japan" on tags throughout the machine along with some labels being in Japanese.