Leaking Hyd fluid out of the starter motor - Technical Troubleshooting discussion in Forkliftaction's forums (2024)

The starter motor continued to leak after the fluid was at the proper level and so last week we raised the forklift and removed the starter. I disassembled the starter and found it has rubber seals. It appears that the seal preventing fluid from entering the solenoid and into the nose cone was leaking and the seal that separates the nose from the motor section was leaking. There are 5 seals in the kit. 2 for the solenoid bolt, 1 for the solenoid, one for the plate between the nose cone and motor section and, 1 that seals the armature shaft.
I polished the armature and cleaned the starter. It's a 10MT with a 3 bolt nose and high torque model. I considered replacing the brushes, but they were fine and if I have issues later I'll build one with new parts.
I sealed the back cover with a thin bead of the Right Stuff to prevent only other fluids from entering the starter in case a hose fails.
I reinstalled the starter yesterday and when testing found a hose seeing on the other side of the engine. It was the hose from the pump to the steering. I made another hose and installed that this morning.
This afternoon I have run and extensively tested the forklift raising the forks many times and driving it under a load and am GLAD to Report that there are no leaks.
So, instead of cobbling the forklift with a valve it is fixed properly. I hope this helps someone else.

Update: The kit arrived over the Thanksgiving weekend and my plan was to remove the starter motor and reseal it today. I have the full service manual, but there's no instructions on how to access the starter motor. It's buried and will require jacking up the lift and removing items from both underneath and from the top side. Before jacking up the lift I remove my drip tray from underneath and it was almost dry (just a couple of drops). So, I checked the hydraulic oil reservoir and found it just over full my 1/4 inch. That made we wonder if I had checked it improperly before. I referenced the manual and it said that it should be checked with the fluid hot the forks lowered and the engine off. This makes me wonder if I had checked it with the engine running and overfilled it. Granted the forklift leaked when I bought it, but nothing to say the previous owner wasn't checking it running and overfilling it too.
So now I am going to run it a few times and see if I get any leaks. I do lower the forks and let it run a couple of minutes before turning the engine off. The manual did say that the forklift will spew out the extra fluid if it is overfilled.
On another note the fellow that sold me the starter reseal kit said my S60XL with GM motor has the 10MT GM Starter. In the manual it doesn't show or talk about the starter reseal kit in the starter section. I did find information on the 10MT and a photo of the seal kit and where the parts are installed. With so many people complaining about the hydraulic oil leak maybe this will shed some light on correct fluid level or that there is a seal kit available.

The starter motor is supposed to be sealed. I read that the seals aren't available anymore. Then I searched eBay and found a kit. I am waiting for an answer that it will specifically fit my S60XL. I have the full service manual and it has an exploded view of the starter and I don't see enough seal in the image to totally keep the fluid out. I'll report back if this turns out to be the fix.

to the return line back to the reservoir

Did you add the valve to line going to the filter or is it the line coming from the reservoir?

it was just a standard ball valve off of the shelf. Hope it works for you to.

What valve did you use on the return line? Do you have a part number? Thank you.

We put the valve under the dash so to speak, where it is easy to get to. It is the return line that also powers the jet pump. I am not sure what the full fix would be. This solved our problem and it is an old forklift that I already had put to much money into. As for the sensor I have no idea, not even sure if it has one. You can access part schematic's on line that should help you find it if there is one. Good luck!

Hey man can I get some more info on this, I'm having the same issue and wondering which line to put the ball valve in and what the full fix would be and where the sensor for the oil level because now I can't get the truck to start after replacing the starter

No we just installed the one. And yes a check valve would probably work. And yes this fix is still working! As long as the ball valve is turned off after use

Hi, I know your post is a little old but I'm just curious if you put a ballvalve on the return line by the hydraulic tank fill? Also, do you think a check valve would work? Then you wouldn't have to ever shut anything off but this way it wouldn't drain back.

Well I don't know if anyone cares, but we have fixed the problem! I know it has been quite awhile since the last post here. Please keep in mind the repair of this forklift is not my main function and is very low priority. My hunch that the system was bleeding of was correct. To test this we placed a ball valve on/in the return line from the control valve. When finished with the forklift simply shut off the valve and wonders of wonders no leak!! With the valve in the off position the lift will not start so no chance of running it dry which was a nice plus. And if it is not shut off after use it will only leak oil making a mess to clean up. Since this fix works and I can not see spending any more money on this lift. That is used for maybe an hour a month at most. I am done, if it was used more I would probably replace the valve. To recap what was done when in the shop (not ours) they replaced the starter supposedly 6 times checked the scavenger tube and so on for obstructions. When we got it back we opened it up and checked the venturi and jet pump everything looked good there. Replaced the starter one more time as that is what everyone says it is. still leaked so we opened up the starter and went through the seals saw some weak areas and reinforced them still leaked. Bought and installed new hyd pump got somewhat better but after about four days started leaking again. last installed ball valve in return line and now no leaks. So to be honest I am not sure if the pump and starter was necessary or if it took all of the above to fix it but we are back in business now! I hope this will help someone else down the road or maybe someone has a simple fix for this and I can remove the valve and put it back as designed because right now if you don't know about the valve your not starting it which might be just extra security.

Well we got the new pump and installed it! for four days not a drop leaked. Left Friday night and on Monday morning came back to a small puddle. It has been slowly growing over a couple of weeks now. The only thing I can think of is something has to be leaking/bleeding off and filling the bell housing somehow.

I think Ive found the problem, I recently spent a good amount of time on the truck we have with that issue, and as mentioned in a earlier post, i Believe it was the hydraulic pump, which cured the problem, we had flow from the jet pump, but it may not have been enough for the jet pump action to draw the excess fluid out of the bell housing, and actually the way its designed, if your flow is too low you will instead, fill the bell housing, so far after checking this unit out since the replacement, the bell housing is holding a slight amount of oil on the bottom,