slow/ weak hydrualics.

warburtonplayer · Mar 18, 2008

The hydrualics on my shibaura S700 is really slow and weak. It will not pick up my tiller because it does not have enough power. It goes up and down with nothing hooked up just fine but once it has an attachment it will not pick anything up. Any ideas know what could be the problem?

Wayne County Hose · Mar 18, 2008

When you say hydraulics, is there more than 1 cylinder involved, or multiple components? Was this all of the sudden, or a gradual thing? Please post more details.
If it was gradual, start on the suction side and change the strainer and fluid, filter if there is one. If it happened suddenly, my bet is something wrong on the suction side (sucking air) or a faulty pump but I would do a pressure check to confirm a pump issue. Well, I would do the fluid/strainer anyway, as it's much cheaper than a pump.
Slow does point towards the strainer being clogged, slow and weak points to a pump.

warburtonplayer · Mar 19, 2008

It is slow and weak. I am not even sure where the filter might be on the tractor. The PTo is the only hydrualics on the tractor no extra ports. The pto seems like it has no power to pull anything up. It also jerks sometimes and the adjustment valve on under the seat I have tried to pull it all the was out and all the way in and no change at all in the speed or power.

RonMar · Mar 19, 2008

Jerky operation is usually a symptom of air in the sysem. Find the pump, and start following the lines. Make sure every fitting you come across is tight. Eventually you will find that one line from the pump goes to a control valve of some sort, and the other line from the pump ends at some sort of a resovoir. There is most likley a strainer in the resorvoir.

Good luck

Soundguy · Mar 19, 2008

Are you saying the pto has no power? or that the 3pt lift has no power.

Check your service manual to find where the filter is.. many of the jap scut/cut's tractors have a strainer that can be washed.

Ditto everything WCH said.

soundguy

Soundguy · Mar 19, 2008

RonMar said:
Jerky operation is usually a symptom of air in the sysem. Find the pump, and start following the lines. Make sure every fitting you come across is tight. Eventually you will find that one line from the pump goes to a control valve of some sort, and the other line from the pump ends at some sort of a resovoir. There is most likley a strainer in the resorvoir.

Good luck

Jerky operations can also be bad check valves or pistons in a piston pump.. can also indicate leakdown and correction / circuit regeneration in an unloading style valve.

soundguy

Wayne County Hose · Mar 19, 2008

There will be 2 hoses connected to the pump. Follow the larger one. Check it's entire length for damage, wear, or cracking. Wherever it goes, there is probably a strainer on the other side. You want to remove it and clean it, and change the fluid. This is, in my opinion, the best place to start.
RonMar is correct about air causing jerky operation, but I have seen clogged strainers do the same thing, so it could be either. I don't know what kind of pump you have, but Soundguy sounds much more familiar with them than I am.
I'm wondering too, did this happen over time, or suddenly?

warburtonplayer · Mar 19, 2008

t has been like this for a while, the 3 point hitch is the problem the pto works just fine. There are no tubes or anything just the valve under the seat. The hitch will raise but it is slow and it does not have enough power to even pick up a scrapper blade.

Soundguy · Mar 19, 2008

I don't have any manuals on a Shib s700.. but you should since you own the tractor.

Check the hyds section.. look for troubleshooting tips. it may show you where to check / clean a strainer or suction filter.. may also tell you where to attach a test gauge to check pump pressure or safety valve crack/open pressure.

Is your hydro pump engine mounted and plumbed with hard lines back to the center section.. or does this unit have live pto and use a pump in the center section?

post back with details.

( to WCH.. I'm not specifically familiar with his machine.. but have owned and worked on other jap made machines.. and ford/NH compacts are generally shib's.. etc.. )

Soundguy

warburtonplayer · Mar 19, 2008

the pump is mounted on the front of the tractor infront of the injector with hard lines. I see no evidence of a filter or screen. Both lines go back underneath the seat.