slow/ weak hydrualics.

[warburtonplayer]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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.

 

[warburtonplayer]

re ae a few pictures of the hydrualic system.

 

[warburtonplayer]

Ok so I talked with West Kentucky Tractor today and I found the hydrualic filter. It was nice and clean... So we got it down to the hydrualic pump is going bad. He actually has one for $350 that will for sure be working. So should I repair or get a yanmar? Any ideas keep in mind there is nothing else wrong with the tractor I am just tired of trying to find parts for a shibaura.

 

[Soundguy]

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.

If there is a strainer, then it will be in the center section... you will need to look at a hyd ckt to find it.

On some of the jap models, there was a cylinder filter that slid out of a plate on the bottom of the center section near where the hard lines entered.. still on some there was a triangular plate that covered a strainer... etc.

post back with more details.. pics of the area where the hard lines enter will be helpfull.

soundguy

 

[Soundguy]

Ok so I talked with West Kentucky Tractor today and I found the hydrualic filter. It was nice and clean... So we got it down to the hydrualic pump is going bad. He actually has one for $350 that will for sure be working. So should I repair or get a yanmar? Any ideas keep in mind there is nothing else wrong with the tractor I am just tired of trying to find parts for a shibaura.

Is the strainer under that 3 bolt plate where the hard line enters?.. or was it a tube style.

In any case.. before i would determine if it was the pump.. I'd like to see a pressure test, and the condition of the lift oring/piston.

A blown oring will prevent pressure buildup and cause a weak slow lift.

more work nbeeds to be done before you throw int he towl.. or start throwing parts at it blindly.

Get a service manual.. that is the first thing you need to do! ( or at least an exploded parts diagram.. )

soundguy

 

[warburtonplayer]

ok here are more pictures of the lines and pump there is only one filter that is behind the one line with the triangle connector on the side of the tractor

 

[Matt_Jr]

All hydraulics have a bypass valve that regulates the line pressure. This is done as a safety mechanism so that your tractor parts don't break when lifting something too heavy. They are even in car power steering systems. The bypass valve is held in place by a spring. To increase/decrease pressure you have to install/remove shims that fit behind the sring and valve. If the spring is broken you loose almost all pressure. You would only have enough pressure to move the arms up whith nothing attached. Find out where your bypass valve is and remove it. Usually held in place near the high pressure line off the pump behind the banjo fitting or behind a bolt near the high pressure line. Some people have been known to add shims to increase their pressure to get more lifting power. However that only works if the spring isn't broken.