[AT] I need help on 3 pt

[Clint D]

well, I am at my wits end over this no hyd pressure? It just does not make any
sense, I have been messing with mechanical stuff now for over 40 years and it
usually is not that hard for me to get a problem figured out eventually, but this
problem is killing me!!!

I can crack my main pressure (output ) line at the valve block and have pressure
that will blow 20-30'
On the main out put line, if I crack it all I get a barely a drip.

I have removed the poppet relief valve several times, I have cleaned it each time,
it seems to move freely to me, but I do not even get a hint of pressure even when
the tractor first starts up.

Do these poppet type relief valves  just flat go bad? could it be it just will not
close all the way? anyone ever have a permenant problem and need to replace one?

I do not mind replacing it, but I just do not want to be chasing my tail if it
could be something else.
This block valve seems pretty simple to me and cannot think of anything else
inside that could be wrong?

suggestions?

Clint




> Most modern tractors have pressure lubricated transmissions and rear ends. They
don't
> need hydraulic pressure to operate unless they have a power shift unit of some
kind but
> simply pump the oil to where it's needed like an engines oil pressure system.
some use
> separate pumps but some use the main hydraulic pump.
>
> If the system uses the main hydraulic pump for transmission lubrication there
could be another pressure relief valve or a bypass valve.
>  I've also seen an internal tube broken which allowed the full flow of the pump
to dump
> into the transmission with corresponding loss of pressure.
>
> I think some tractors use a flow divider valve to provide priority first to the
power steering,
> second to the lubrication system and third to the 3pt or remotes
>
> On 28 Mar 2005 at 12:37, Clint D wrot
>
> > > Clint,
> > >
> > > Does your hydraulic pump provide pressure lubrication for the
> > > transmisssion?
> > >
> > > Is it possible you have a transmission lubrication line unconnected inside
> > > the transmission and it's acting like an open pressure relief valve?
> >
> >
> > This is interesting? how could I tell if it provides pressure lubrication to
the
> > trans?  as far as I can tell so far, this pump provides hyd. for the 3 PT,
Power
> > Steering and aux hyd's
> > If this was the case? would I have pressure to run the gears? The trans gears
are
> > working, packs, etc.
> >
> > Clint