Hydrostat won't move if one tire looses grip

[jaredclark]

Hi
New to this, I recently bought a late 70's? Willmar Wrangler hydrostatic 4wd. I swaped in a Kubota v2203 4cyl. diesel. After getting it running the first thing I tried to do with it was back blade my driveway. If I put any pressure down on the bucket the front tires start to spin and the loader will not move until I lift the bucket. so it is tough to get anything done without taking weight off the front tires.. It looks like all the drive motors are hooked with just a tee that splits to front and rear. Then a tee at each axle to the individual motors. If anyone has worked on on of these systems and could give me some direction.

Thanks for your time
Jared

 

[RNeumann]

So 4 individual drive motors? No axle shafts or drive.

No expert but it seems you are on to something with the tees. That doesn’t sound right. It would seem one lever should “open” 4 valves equally. Again, no hydraulics expert......just my observations.

 

[SSdoxie]

Two basic principles to keep in mind. 1-flow will go to path of least resistance. 2- pressure is equal throughout a circuit.
With 4 motors powered by 1 pump and connected only with Tees, when 1 or more motors loose traction flow goes through the spinning wheel motor and pressure to all motors is reduced to only what is required to spin that motor(s).

 

[oldnslo]

Does a single pump feed all four motors? If yes I suspect it is not plumbed correctly but not 100 % sure.

Since these are center pivot steer I suspect the left front & right rear should be in series and right front - left rear would be in series. This way opposite tires are always trying to drive

 

[LouNY]

Or add in some flow dividers;
I have no idea of the flow rating you are dealing with but a 4 port would provide equal flow to all four motors;
.11 cu in 8 GPM 4 Section Rotary Flow Divider MTE | Divider Valves | Hydraulic Valves | Hydraulics | www.surpluscenter.com

Or a couple of 2 ports;
.11 cu in 2 GPM 2 Section Rotary Flow Divider MTE | MTE Hydraulics | Brands | www.surpluscenter.com

As far as plumbing the motors in series, depending on the motor some do not want the back pressure that series plumbing would have.

 

[oldnslo]

Lou is correct, some motors are not designed to operate in series.

 

[jaredclark]

So 4 individual drive motors? No axle shafts or drive.

No expert but it seems you are on to something with the tees. That doesn稚 sound right. It would seem one lever should 登pen 4 valves equally. Again, no hydraulics expert......just my observations.

Yes each wheel has its own motor

 

[jaredclark]

Thanks
How would I know if these motors will work in series? these Motors have case drains if that matters

also will these flow dividers work when flow is reversed?

 

[jaredclark]

the motors have 1 1/2 inch lines supplying fluid to them. do you think a flow restrictor would allow the rears to do for of the work
Hydraulic Flow Restrictor Valve SAE 16

 

[oldnslo]

If motors have case drain lines they can typically be operated in series.

Yes flow dividers work in both directions