[AT] I need help on 3 pt

[Clint D]

Larry

Please see below


> The relief valve is usually part of the same casting as the control
> valve,

**** The aux. valve does have two relief valves

 Clint.  The diagram I have on my Kubota shows it that way also.
> Typically, auxiliary equipment, such as a loader, are either operated in
> series with the 3-point,

**** mine is in series with the 3Pt

or there is a petcock arrangement on the
> control block to switch fluid pressure to one or the other of your
> attachments.

**** Not this setup


  On my Kubota, the diverter valve is on the lift cylinder
> right behind the driver's knees.  In addition, there probably is an
> auxiliary power block located along the side of the engine in the high
> pressure line coming from the pump.

This does have a small block mounted to the pump, it has two pressure valves, a
high pressure line from the side of the pump directly into the block, and where it
mounts, it has an O'Ring and a aprox 3/4 port going inside the pump. It also has a
larger steel line that goes to another block about half way from the pump and the
3 Pt and aux control valve. the 3 PT and aux control both have a lines going to
it.
The main suction line comes from the bottom of thge trans case, thru a screw on
filter, and on up to the rear the pump

The pressure valves in the block mounted to the pump, I attempted to pull these
apart, one side has the adjustments and the other side of the block has a cap
cover with bolts, I started removing the bolts and there is really stronge
springs, so I quit removing them for the time being

>
> The Kubota workshop manual lists these possible problems in the
> troubleshooting area:
>
> Unable to lift -

**** That is will not dop, it also has nop pressure whatsover to it

- Insufficient oil,

**** Plenty of oil


Clogged oil filter,

**** New filter


Obstructed
> hydraulic pipe,

**** dont think so

excessive load,

**** no load

 Improper adjustment of relief valve,

**** were not adjusted on, but possibly one stuck???

> defective gear pump,

**** sure wondering, but was working fine before tear down???


 improper position of directional valve,

**** ????????????????

 defective
> control valve,

**** Seems to work

 broken O-ring at hydraulic piston or cylinder cap.

**** Dont think so? loader is off, and 3 PT was never touched


>
> Slow to lift -- Low oil temperature, loose inlet pipe connection (allows
> air to enter), clogged oil filter, insufficient oil, defective gear
> pump, scratched relief valve.
>
> There are strainers on the outlets of the oil reservoir.

**** I have not seen any strainers

  Those are
> separate from the hydraulic oil filter, and those may be clogged.  I'm
> not sure how those are removed on your tractor, but usually they are
> screwed in from the outside.
>
> USUALLY, there is some sort of cap over the adjustment for the pressure
> relief valve.  On some systems though, it's out in the open and
> unprotected.  Regardless, it's tempting to tweak that screw and
> completely mess up the working pressure of your hydraulic system.

***( Will not adjust on them unless totally necessary, they should still be fine,
they were not removed.

>
> You don't have any dents in the steel lines going to and from your pump
> do you?  That sort of thing can cause the symptoms you have.

**** I removed the pump again this evening, checking for any thing like that,
checking for blown O'Rings, etc. I have the pump, filter. lines from pump and
resorvoir all completely removed. So now I am down to removing any relief valve in
the two blocks??????

Clint


>
> Larry
>
> -----Original Message-----
> From: at-bounces at lists.antique-tractor.com
> [mailto:at-bounces at lists.antique-tractor.com] On Behalf Of Clint D
> Sent: Sunday, March 27, 2005 8:54 PM
> To: Antique tractor email discussion group
> Subject: Re: [AT] I need help on 3 pt
>
> Larry
>
> Thanks for your reply, I went this evening, pulled the pump and checked
> everything
> from the pump back to the loader bucket control valve and really did not
> find
> anything unusual or suspect.
>
> QUESTION,  I have not checked anything from the filter back to the rear
> end where
> the 3 pt control is, is there supposed to be any relief valves back
> there? I have
> not seen any evidence of any so far?
> I have never done any work around a 3 pt valve, so this is new to me.
>
> What type of areas should a relief valve be for me to check out besides
> at the
> control valve?
>
> this thing has me totally stumped.
>
> Another question, normally on a tractor like this, is there anything
> inside the
> trans. compartments in front of the final drive/rear end that could
> effect this? I
> cannot think of anything myself, but just pulling things from  thin air
> right now
> trying to get this figured out
>
> Clint
>
>
> ----- Original Message -----
> From: "Larry D. Goss" <rlgoss at evansville.net>
> To: "'Antique tractor email discussion group'"
> <at at lists.antique-tractor.com>
> Sent: Sunday, March 27, 2005 6:59 PM
> Subject: RE: [AT] I need help on 3 pt
>
>
> > I would suspect a dirty pressure relief valve, Clint.
> >
> > Larry
> >
> > -----Original Message-----
> > From: at-bounces at lists.antique-tractor.com
> > [mailto:at-bounces at lists.antique-tractor.com] On Behalf Of Clint D
> > Sent: Sunday, March 27, 2005 3:39 PM
> > To: Antique tractor email discussion group
> > Subject: [AT] I need help on 3 pt
> >
> > Well, I went out and tried to bleed the hydraulic system. I run thru
> 25
> > gallons of
> > hyd fluid. I get some pressure from a hose coming from an aux  hyd
> lever
> > control.
> > but with the engine at full throttle I can still hold my finger over
> the
> > end of
> > the line and stop the flow??? A lot less pressure than comes from a
> > water hose!
> >
> > I did have the pump off and all the lines off but see no reason why
> the
> > hyd pump
> > would go from working to being worn out just from R & R it. I checked
> > all the
> > lines and cannot find anyplace it could be sucking air.
> >
> > it is weird, I can get fluid to coming out a line and as it starts it
> > seems to
> > start at a dribble then finally gets a stream going, but like I said,
> I
> > can put my
> > finger over the stream and easily stop the flow, then If I let it sit
> a
> > few
> > minutes, and then try again, no pressure at all, and it will take a
> > moment to get
> > any pressure at all again,
> >
> > could a worn pump act like this? once all the pressure is relieved
> from
> > pulling it
> > off, it just looses all its effect?
> >
> > Clint
> >
> >
> >
> > _______________________________________________
> > AT mailing list
> > http://www.antique-tractor.com/mailman/listinfo/at
> >
> > _______________________________________________
> > AT mailing list
> > http://www.antique-tractor.com/mailman/listinfo/at
> >
>
> _______________________________________________
> AT mailing list
> http://www.antique-tractor.com/mailman/listinfo/at
>
> _______________________________________________
> AT mailing list
> http://www.antique-tractor.com/mailman/listinfo/at
>