I've removed the pump and have it sitting in my shop now. I have some concerns. I see some metal shavings on the filter that sits in the hydraulic oil tank also some plastic or rubber that I have no idea where it came from. How hard should it be to turn the pump shaft with everything removed? I cannot turn it with my hand. I haven't tried a pipe wrench yet but I'm concerned the reason the coupling failed is because the pump is broken or has an obstruction. The serial number of the machine is JST0000762. I think a new pump from cat is like 10k. I haven't removed filter in engine compartment yet to examine it. Does anyone make a rebuild kit for these pumps? Does the plate on the back of the motor have to be removed to replace the coupling? I haven't found a schematic yet that shows exactly what is going on there.
See the attached which may answer some of your questions. If you want some details of a D&A procedure for the pump please ask.
Yes please on the D&A
Thanks for those schematics. I see what I need to do now.
I should have investigated before making the offer. There is a grand total of zero as regards procedures for the hydtat pump D&A. Sorry.
I see they have changed from the pump I have to this new number. Is it a better pump?
What Part Number pump do you have installed.? All I see at the minute is an improved assembly procedure for the same P/N of pump.
I doubt you'd be able to turn that pump by hand. Have you split the other pumps off and checked them too? IIRC there's the hystat pumps, then the implement pump and then the charge pump. How many hours on the machine? I've seen the pump coupling start to fail on Cat machines as low as 3000 hours. Usually its just the plastic isolators around the mounting bolts that start to crack and break at that point. Yes you will have to remove the adapter plate from the flywheel housing. The coupling is just a big plastic thing bolted to the flywheel.
I think it has 2700 hours on it. The plastic disc appears intact. The splines are just stripped in the center. There is evidence the pump has been off before. The mounting bolts on mine were 14mm spline headed. I bought the machine from an individual and he was a liar. The charge pump has junk yard pen writing on it "299d XHP". I'll try taking pumps apart today
The two hystat pump mounting bolts are supposed to be M14 x 40mm long with 12-point heads. No data plate with a Part Number then.?
Yep the pump mounting bolts are definitely 12 point head from factory. Pulled a lot of those pumps out.
Probably normal. Post some pictures if you're concerned. In failures that screen will be covered in fine metallic stuff and sometimes chunks. It cops all the wear material from the two drive motors also. To get the full story you would need to cut open the hydraulic filter and pull both speed sensors off the drive motors. Metal loves sticking to speed sensors.
There's at least 1 plate with a serial number is saw when I put it in the shop. I haven't been over to the shop yet today because of the snow storm. I started to call it 12 point and then I was unsure if that applied to metric so I searched 12 point metric and spline came up.
The 341-7635 Part Number is for the Work Tool (implement) pump which is available separately. The machine was built in July 2014 so the pump S/N tag with a build date of June appears to be kosher. 398-7456 is the Part Number for the hydrostatic drive pump. Both Part Numbers should be serialised. Unfortunately I can’t date that pump from the S/N.
I used a pair of channel locks and a rag to prevent damage and I was able to turn the shaft without too much difficulty. I only turned it a 1/4 turn or so but it doesn't seem to be frozen.
That is normal. You would never turn it by hand. Probably just the usual coupler failure we see often.