hydraulic pump and hydraulic motor overhaul

redneckjeep87

redneckjeep87

Landscaper Extroidanaire
Joined
Oct 10, 2007
Location
Woodleaf, NC
Anyone have any experience rebuilding/overhauling hydraulic pumps and motors? I ordered a reseal kit for the right pump on my toro walk behind took a look at the kit and promptly took the pump and kit to the local hydraulic shop in salisbury. I dont think it would be that bad but there are a $#!@ ton of orings in that thing apparently and i freaked out about screwing the pump up. Those things are NOT cheap. I would love to do it but am apprehensive without having someone that know what they are doing to give me a hand.
There is still the left side pump (no problems as of now) and both wheel motors. Im not sure if i will have to have the right wheel motor rebuilt or not yet. The right side is what i was having problems with.

In the mean time im waiting to hear back for the labor estimate to put the overhaul kit in the pump.
 
I have done a few. Typically when they go the y are not rebuildable unless there are replacment bushings. If the scoring in is to deep or in ght e housing it's trash. Piston pumps are a different, I assume you are rebuling gear pumps & motors.

i
 
Jeff i believe so. Im not sure if there were any bearings in the overhaul kit or not. The pump still worked it just didnt work well when warm, especially on hills. Hopefully its not the wheel motor, but i have found an overhaul kit for them for 57.00 each. I do have the schematic downloaded somewhere so i will have to take a look. I should have known you had done some with your carney ways lol
 
Have you checked the pressures & the relief? Could just be a piece of trash not allowing the relief to completely close or could be a seal in the relief also.
 
Negative. I did not. It was a problem that gradually popped up several years ago. Mower sat, then i picked it up off my dad for myself and now trying to fix. It would work fine until it warmed up a bit and then wouldnt pull on right side under load (such as a hill).
 
If it were me.

Find out what pressures you should have.

Check said pressures, could be a charge pump issues, I don't know your application or equipment.

Check relief.

if all that is bad. swap motor from side to side. this will tell you if it's the pump or the motor.

I probably would not try a rebuild myself of the bad part. In my experience it's best to replace or find a rebuilt one by a reputable shop.
 
There's countless ways in which you could be losing pressure. The best way to find out is to have a tech do a pressure test (typically requires plumbing in an adjustable flow restrictor and gauge) on the suspected system to determine if it's a wheel motor or the pump.

The pump rebuild isn't really that hard. Most of the O-rings you saw were for fittings. Typically, inside the charge pump, it's metal on metal, which is why if you're losing power when warm, I'd suspect that the fluid has become contaminated and has worn the rotor and pump body. Depending on the unit (yours is likely a Hydro-gear system), it's pretty much cheaper to replace the pump than rebuild. Don't, I repeat, DON'T replace the pump without flushing the system. You'll end up right back where you started.
 
Hydro gear bap10 pumps, cant remember the wheel motors by memory. @maulcruiser what would be the best way to actually flush the system? Only thing i know is to completely drain everything i can throw a filter on it and run it for a short time then pull filter, drain again and then put everything back
 
Gear pumps are pretty tough, remove all the hoses and flush them, flush the tank. Basically you havv to clean everything & filter or replace the oil. At work we filter down to 2 micron however we use EDC's on piston pumps. Iirc 10 mic. is fine on a gear pump. So if you plumbed in a remote oil filter which is typically 10 micron you should be fine. However I have a high pressure filter that and housing that is 2 micron I will sell. if interested.
 
It does have a remote filter, toro specs a 25 micron which is bs. What would be the reasoning for zuch large diameter openings? How dhould i go about fluzhing the system when i put everything back together?
 
It's a Pain in the ass. When I have to do this on a machine. I remove every hose one at a time and run some diesel or citrus through them and blow out with air. can also get some foam plugs that you can blow through the hoses. Also have to clean the tank.
25 mic. Is pretty big, however gear pumps are designed to handle cap like that..
 
I won't get into how much I despise Toro and everything they build, but I'd definitely be running a better filter. Most commercial units spec 10 microns, and you'd benefit from the same in your piston pump setup. As for flushing, we typically drain everything we can, refill with fresh oil and a new filter, then operate the unit until the system is hot, then drain, refill, and new filter again. That should take care of the large particles.
 
@maulcruiser I agree with you on the toro thing, except for the hydro proline with the t handle. They are a pretty good mower all except for how light they made the deck, out of all the true walk behinds they are the only ones that are comfortable to me. I CANT do the pistol grip pos style, my hands hurt enough and go to sleep enough on their own without the help from those. Im glad that is the procedure of flushing the system bc that is what i was going to do.
 
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