[AT] hydraulics problem

Brett Phillips bphillip at shentel.net
Fri Feb 10 07:07:02 PST 2006


Cecil:

I wish that JD had used that sort of system on the 420/430!  ;-)  Instead,
the valve has two shafts that are loosely coupled, and the play in the
coupling is what operates the valve sleeves (not a conventional spool).
This setup can be a nightmare if play develops elsewhere in the system (and
boy does it ever...).  I believe A-C used a system similar to what you
described, and maybe Minneapolis-Moline did too?  They were much less of a
tack-on system than the JD 420/430 mess, and from what I hear, they work
pretty well.  At one time I gave serious consideration to replacing the
rotary valve with a Char-lynn hydrostatic valve, and eliminating the Ross
steering box on my 420.  If the danged thing wasn't such a collector's item,
I might have done it.  I'm sure it would have worked better than what I have
now.  Hydraulics were not Dubuque's strong point in the mid-late '50's...

Probably more opinion than fact, so it's JMHO

Brett Phillips
Strasburg, VA



-----Original Message-----
From: at-bounces at lists.antique-tractor.com
[mailto:at-bounces at lists.antique-tractor.com]On Behalf Of Cecil Bearden
Sent: Friday, February 10, 2006 9:03 AM
To: Antique tractor email discussion group
Subject: Re: [AT] hydraulics problem


Lew that link did not work.
However, a lot of those types of valves work with the steering gear.  When
the dhaft is turned, the valve works on play in the worm gear of the
steering gear.  As the worm moves in or out, it moves the valve to send
pressure left or right.  If there is no "play" in the steering worm gear,
the valve cannot move and cannot work.  I had shimmed up the steering gear
on my MF85 so ther was no play when I rebuilt the steering gear, and The
steering only went one way, and stayed there!!!!!

Cecil
----- Original Message -----
From: "Lew Best" <bee_keeper at earthlink.net>
To: "'Antique tractor email discussion group'"
<at at lists.antique-tractor.com>
Sent: Friday, February 10, 2006 12:02 AM
Subject: RE: [AT] hydraulics problem


>
> Thanks Cecil
>
> Guess I wasn't clear enough; this is a rotary valve in the steering
> shaft.  When putting pressure on the wheel to say the right it sends
> pressure to the cylinder to "help" push the wheels one way.  Once you
> release the steering wheel (or stop because you've reached the point you
> want to turn it to) the valve drops back to neutral.  For a pic you can
> go to http://img.photobucket.com/albums/v707/lewbest/steervalve01.jpg.
> The top & bottom hoses go to the cylinder; right goes to pump pressure &
> left to pump suction.  The gearbox on the steering still functions;
> hydraulic power just "helps" move the steering knuckles.
>
> Lew
>
> -----Original Message-----
> From: at-bounces at lists.antique-tractor.com
> [mailto:at-bounces at lists.antique-tractor.com] On Behalf Of Cecil Bearden
> Sent: Thursday, February 09, 2006 10:51 PM
> To: Antique tractor email discussion group
> Subject: Re: [AT] hydraulics problem
>
> Lew
> you mentioned that the roll pins had been replaced.    Check to see that
> the
> control valve can move in and out.  My old Massey had a slot that the
> roll
> pin in the control valve shaft slid in and out to regulate the fluid.  I
>
> reamed it out to pin it solid. and had no more Power steering...
>
> Cecil in OK
> ----- Original Message -----
> From: "Lew Best" <bee_keeper at earthlink.net>
> To: <at at lists.antique-tractor.com>
> Sent: Thursday, February 09, 2006 6:25 PM
> Subject: [AT] hydraulics problem
>
>
>>
>> Hey guys
>>
>> Got a problem; (so what else is new)?
>>
>> On an old John Deere 420 power steering it's doing something crazy!
>> Solved a few problems yesterday; got it to turning pretty good one way
>> but not near as good the other.  Had a bad leak on one of the rotten
> old
>> hoses coming from the control valve to the cylinder so replaced the
> hose
>> today thinking that would fix it.  Well, that made things worse!
> Seems
>> that when it had pressure on the good hose that the leak let the
> return
>> fluid from the cylinder out so it worked.  Now (with no leak for the
>> return flow) no turn either way.  Someone had obviously had problems
>> with this steering before (had sheared keys & roll pins, etc.) so now
>> I'm kinda grasping at straws.  What is obviously supposed to happen is
>> when you turn there should be pressure to one end of the cylinder
> making
>> it push & the fluid from the other end be allowed to go back to the
>> suction side of the pump.  Is there a check valve inside of the
> control
>> that could be stuck? I've removed the hoses one at a time (right, left
> &
>> return) & all seem to squirt fluid "when they should."
>>
>> BTW I wanted to replace one of the shafts in the valve (pretty well
>> mutilated) but the shaft is no longer available thru JD.  Asked about
> a
>> complete valve & same response.  Hate to tear into it not knowing if
> any
>> parts available (seals, etc.) but guess I'll have too.  No good the
> way
>> it is!  Anyone got one (or know of a source) without having to give an
>> arm & a leg for it?
>>
>> Any ideas appreciated!!!!!!!
>>
>> Lew
>>
>>
>> --
>> No virus found in this outgoing message.
>> Checked by AVG Free Edition.
>> Version: 7.1.375 / Virus Database: 267.15.2/253 - Release Date:
> 2/7/2006
>>
>> _______________________________________________
>> AT mailing list
>> Remembering Our Friend Cecil Monson 11-4-2005
>> http://www.antique-tractor.com/mailman/listinfo/at
>
> _______________________________________________
> AT mailing list
> Remembering Our Friend Cecil Monson 11-4-2005
> http://www.antique-tractor.com/mailman/listinfo/at
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.375 / Virus Database: 267.15.2/253 - Release Date: 2/7/2006
>
>
> --
> No virus found in this outgoing message.
> Checked by AVG Free Edition.
> Version: 7.1.375 / Virus Database: 267.15.2/253 - Release Date: 2/7/2006
>
>
> _______________________________________________
> AT mailing list
> Remembering Our Friend Cecil Monson 11-4-2005
> http://www.antique-tractor.com/mailman/listinfo/at

_______________________________________________
AT mailing list
Remembering Our Friend Cecil Monson 11-4-2005
http://www.antique-tractor.com/mailman/listinfo/at






More information about the AT mailing list