Rebuilding Hydraulic Pump?

[DonMountain]

After asking several questions on here about repairing a hydraulic pump leaking oil into my engine on my 59' International Cub LO-BOY, I bought the rebuild seal package and unbolted the exhaust pipe and muffler (to put a new one on and give clearance to the removal of the hydraulic lines and pump) and took the two mounting bolts out of the pump and pulled it out of the block. The pump drive was missing the drive gear and nut and key and special washer. I saw the key drop to the ground under the tractor (of course its lost in the tall grass since I couldn't mow it) and the gear is still sitting inside the engine lined up with the big drive gear I can see in there. The pump was still working when I took it apart, so the pump drive shaft and gear must have been functioning before removal. And I can't find my magnet to look for the key on the ground. But where could the nut and lock washer from on front of the shaft gone too?

[AL Farmall Boy]

I would get the gear out of there and then fish around with a retractable magnet (the are only about $2 at the auto parts store). If you still dont find them, remove the oil pan and it is possible the parts are in there. That probably be your best bet. If you need new parts (quality ones), check with TM Tractor (site sponsor.....link at bottom of page) becuase they carry the rebuild kits (which you already have, the small key, the nut, and the washer. They should have all gaskets too....including a new oil pan gasket, which you'll need if you pull the oil pan. I prefer to call TM Tractor on the phone and speak directly with Tom, so you may want to try that. GOOD LUCK!

[DonMountain]

I would get the gear out of there and then fish around with a retractable magnet (the are only about $2 at the auto parts store). If you still dont find them, remove the oil pan and it is possible the parts are in there. That probably be your best bet. If you need new parts (quality ones), check with TM Tractor (site sponsor.....link at bottom of page) becuase they carry the rebuild kits (which you already have, the small key, the nut, and the washer. They should have all gaskets too....including a new oil pan gasket, which you'll need if you pull the oil pan. I prefer to call TM Tractor on the phone and speak directly with Tom, so you may want to try that. GOOD LUCK!

I found the key laying on the ground, thanks to a magnet off the refrigerator. And I grabbed the gear in the engine with a pair of needle nosed pliers gripping the outer cast surface. And both of them look ok and the gear and key slipped onto the shaft ok. I felt around inside the engine with my fingers as far as I could reach and couldn't find the lock washer or nut. So I assume now that they went down into the oil pan as you suggested. I did buy the rebuild kit from TM tractor. I guess I might as well pull the oil pan and see if I can find any usable parts in there. And order the ones I am missing and the pan gasket from TM. Do I need to pull the cover over the front of the clutch in order to pull the pan? Or if I take the pan bolts off will the pan slip out of there?

[Dale Finch]

You may be about to face one of the truly annoying design aspects of the cub!! Make sure you do the oil pan removal and installation when you have plenty of patience!

Yes, you do remove that half moon plate at the front of the clutch housing. Then remove all the oil pan screws (of course after you have drained the oil!) Those 3 bolts at the rear of the oil pan are a real b@#*ch to get out and worse to get back tight again. A 1/4" wobble extension is about the only way I have been able to get it done. You might try fishing the washer and nut out through the drain hole before removing the pan...i was able to do that one time.

Good luck!

[Hengy]

Yes, you have to pull the cover off the front of the bell housing in order to get at the three back bolts on the pan. Those three bolts are a bugger to get after, but it is made easier with a 1/4"drive 1/2" universal joint socket on a long extension. Be careful when reinstalling the pan so that you don't over-tighten the bolts and warp the lip of the oil pan... Sure-fire leak waiting to happen!

The nut, washer and gear came off most likely because the last person who was in there didn't lock in the little tab on the retaining washer... Definitely a good idea to make sure that this is really well set...

Mike

[Eugene]

Before I rebuilt the hydraulic pump, I would reassemble the gear, washer and nut - reinstall - etc.. Try the old pump first. Probably is good.

[Hengy]

Just as always... A day late and a dollar short with my post...sorry to "double up" Dale!!

[Denny Clayton]

You may be about to face one of the truly annoying design aspects of the cub!! Make sure you do the oil pan removal and installation when you have plenty of patience!

Yes, you do remove that half moon plate at the front of the clutch housing. Then remove all the oil pan screws (of course after you have drained the oil!) Those 3 bolts at the rear of the oil pan are a real b@#*ch to get out and worse to get back tight again. A 1/4" wobble extension is about the only way I have been able to get it done. You might try fishing the washer and nut out through the drain hole before removing the pan...i was able to do that one time.

Good luck!

Dale's right. You have to drain the oil anyway, just don't get in a hurry to pull the pan. If they are in the pan one or both could flow out with the oil (not likely). Fish around with a telescoping pencil magnet. You might be surprised what you find.

[DonMountain]

Dale's right. You have to drain the oil anyway, just don't get in a hurry to pull the pan. If they are in the pan one or both could flow out with the oil (not likely). Fish around with a telescoping pencil magnet. You might be surprised what you find.

Of course I have probably changed the oil at least a few times since the nut and lock washer came off the pump drive gear. And the only reason I pulled the pump was because the hydraulic oil was leaking into the engine past the drive shaft O-Ring seal. And I don't know how long that has been leaking. Or does the nut missing cause that to leak? But I have a couple of clean gallon ice cream buckets to drain the 2 gallons of hydraulic oil in and see what I find. And maybe I will run up the auto parts store and see about one of these magnet retreaval tools you all are talking about. Before I try removing the oil pan. I thank you all very much for the help so far. And I haven't even gotten to the hydraulic pump rebuild yet.

[Don McCombs]

The nut is a standard 3/8-24 jam nut available at your local hardware store.
The woodruff key is a standard 1/2 X 1/8 #3 key, available from the same source.
The OEM washer is quite expensive for what it is. Over $20. If you don't find the original washer, a suitable substitute is a 3/8 inside toothed lock washer. Same source. After you have assembled everything, lock the gear in a vise between two blocks of hardwood and hit it with the impact wrench.

[Eugene]

the only reason I pulled the pump was because the hydraulic oil was leaking into the engine past the drive shaft O-Ring seal. Or does the nut missing cause that to leak?

Rebuild the pump. If hydraulics were working, loss of nut and washer didn't cause the hydraulic leak.

[bythepond88]

Take Denny Clayton's advice and fish around the pan with a telescoping magnet after draining the oil. The nut and washer from my pump came off, and they were right under the oil pump pickup. I had to finesse them to get them out the drain plug hole, so I doubt that they slipped out during any of your previous oil changes.

[DonMountain]

Take Denny Clayton's advice and fish around the pan with a telescoping magnet after draining the oil. The nut and washer from my pump came off, and they were right under the oil pump pickup. I had to finesse them to get them out the drain plug hole, so I doubt that they slipped out during any of your previous oil changes.

Ok, I went to town and bought a small magnet I am going to put on a flexible piece of copper wire to try and fish around for the parts. But I also bought a nut, key and internal toothed lock washer to replace the lost ones with also. And if I can't get the old ones out of there, I decided to just leave them in there. I can't see how they could do any damage to the engine since there is a screen on the bottom of the oil sump and they probably wouldn't fit up through the suction pipe anyway. Let me know if there is a real reason to pull the pan?

[Don McCombs]

If your "fishing" trip is unsuccessful, I'd leave them there until the next time you drop the pan.

[Eoghan]

Be warned, that little washer is expensive to replace! hope yours doesn't look like mine did when you find it:


also, those three bolts in the bell housing are tricky even with the wobbly extender. the only way I could do it was to use the stubbiest 1/4 inch drive socket I could find + a long extension, then set it halfway on the bolt (cockeyed) and use lots of upward pressure so as not to strip it. luckily mine weren't on there too tight!