Sunstrand Help Needed

[chris sutton 610]

Wondered if anyone can help me with a Sunstrand pump fitted to a Toro gmt 230, As far as I can see the toro part number is 27-3670.

I had a look at the pump today that's been taken out of the tractor before I got it as it was leaking oil, the only numbers I can find on it are 90-1093  lh and 02-ub 19646.

I thought I saw someone on here had a test bed made up using an electric motor to turn it but can't find it now.

Is there anyway I can test it to find out where the leak is or have I got to refit it back in the tractor,

many thanks for looking.

[stevasaurus 22,872]

Excellent pictures Chris, but I am not much help with the automatics. 

[pfrederi 17,887]

I mounted the Sundstrand to an old frame and clamped the electric motor to the frame  Have no idea how yours mounts sorry....

[chris sutton 610]

1 minute ago, stevasaurus said:

Excellent pictures Chris, but I am not much help with the automatics. 

Nows your chance to learn something Steve, 

2 minutes ago, pfrederi said:

I mounted the Sundstrand to an old frame and clamped the electric motor to the frame  Have no idea how yours mounts sorry....

Many thanks Paul, that's the photo I was looking for

[squonk 41,369]

Your pump looks clean Chris. Did it have any hoses hooked to it for hyd. lift. They leak all the time and get the oil all over.

[chris sutton 610]

20 minutes ago, squonk said:

Your pump looks clean Chris. Did it have any hoses hooked to it for hyd. lift. They leak all the time and get the oil all over.

It has a pipe that goes in underneath and one each side , it has hyd deck lift and hyd steering, the tractor was in bits when I got it and just told the pump was taken off because it was leaking,

I need to hook it up to see for myself where its leaking from, I was hoping to bench test it if possable   

[squonk 41,369]

Most common pump leaks are the shaft where the control shaft is and the o-rings that seal the pump to hyd. motor. It can leak at the motor to transaxle gasket if someone had taken it off and tried using sealer on the mating surfaces in stead of the now obsolete gasket.

[Sarge 3,463]

Most likely the swash plate shaft seals are leaking - look for any signs of oil around those shafts on the sides of the finned housing. Depending upon where the cooling fan is located it can track that oil all over the pump, making it really tough to find the leak. I've also seen the pump housing cover (again, finned round part) leak at the base where it bolts to the pump block. In your last pic - I can see the direction control arm that is red - the shaft on each side is where you want to look very closely. It's a common Sundstrand 90 series pump - parts should be available for it .

 

It looks as though the transaxle is the oil reservoir , it will have to be mounted to that to test it as well as some sort of hydraulic line in a loop to close off the pressure/return ports. You'll have to figure out what direction it turns as well to test it - it will take some pretty hefty power to get it working . I have pre-tested a few Sundstrands using a 36v Bosch drill , but don't really recommend it .

 

Just curious - can you see the splines on the end of that shaft inside the coupling ? That shaft can also be a source of a leak, btw.

 

Sarge

[diesel cowboy 263]

That pumps going to be a pain to setup and bench test without having it bolted to the drive axle.  It looks almost identical to the ones used on the Cub Cadets and some of the John Deeres.  

 

On those there is 5 common spots where they like to leak.  The 4 seals, 2 for the input/output shaft where couplers are bolted/pinned on and the 2 for the trunnion shafts (called control shaft on the horses) that are 90 degrees from the input/output shaft and there is a cork gasket or o-ring that seals where the shaft comes out with a gear on it.  

 

In your first picture the red cap closest to the camera by the filter is the suction line for the oil and the return is through the bearing on the shaft with the gear.  The second pic the 2 red caps are for the hydraulic system ie power steering and lift so you want to loop those together if you try to run it otherwise one of them will spit oil out at you while its turning.  The last pic there is 2 plugs on the top with plungers in them and they're pushed down.  Those are the tow valves and they need to be sticking up somewhere between I think 3/8-1/2 inch for it to work right.  Pushed down like they are now would let the machine freewheel.  There's a good chance that they're stuck down.  Once it gets pressure from inside they might pop back up.  If not you'll have to remove them and see about using a tiny screw driver to push them up from the inside.  

 

If you want to bench test it, its easier with 2 people.  Take the coupler off the input shaft and hook it up to a drill somehow, get a 5 gallon pail about half full of clean oil, and hook a hose onto the suction fitting.  Once that's all setup one person holds the pump in the bucket so the line can pick up oil and the other person runs the drill and moves the lever on the side of the pump.  Seeing as how its been apart for an unknown amount of time I'd pull both tow valves and pour oil into them while spinning it over by hand to get fresh oil everywhere inside it before spinning it with a drill.  Once your ready to spin it with the drill, both people need to hold onto everything tight.  Get the drill up to speed and then move the drive lever on the pump.  Be ready because once it has a prime in the pump and you move that lever it will try to force itself back to neutral and the pump and drill will jump and buck in your hands.                                     Hope this helps

[chris sutton 610]

Just like to thank you all for your valuable input on this topic, a lot of information on a subject i know nothing about but don't fell so bad about tackling the fault and hope i can fix it whatever it turns out to be

[chris sutton 610]

Just a small update, As I was told something hit the pump so ive ordered a crack testing kit to try and find the leak before I refit it.

Once it arrives i'll test it and update progress. 

 

[chris sutton 610]

My kit arrived and I sprayed with cleaner, then with the penetrant and then with the developer, it showed up a small impact on the casing and two small cracks.

Ive taken the pump to a friend who will weld a patch over the damaged area and hopefully repair it.

I await his phone call.

[Sarge 3,463]

Where exactly is that crack ? If it's in the aluminum pump cover - good luck since chasing cracks in the stuff when welding is a joke and can take a lot of time completely stop them.

 

Sarge

[chris sutton 610]

Its on the side of the aluminium casing below the forward / backwards shaft.

[chris sutton 610]

Picked the pump up today after a friend run some aluminium weld over the dodgy looking area, next job will be to test it to see if that cured the leak.

[chris sutton 610]

I've filled the pump up with oil and the weld seems to have cured the leak from the damaged area but there's some weeping from the casing gaskit so I'm going to split the pump and make a new gaskit.