Won't stay in float!

Carpenter · May 16, 2002

Won\'t stay in float!

I went out to mow this morning and my PT425 wouldn't stay in float position. The stick would stay partially forward, but the loader arms would start to slowly raise the front end. The only way to keep it in float was to hold the stick "all the way" forward with my right hand while I was mowing. Anyone else had this problem? Is there an adjustment for the float mode? Help, my arm is tired.

MossRoad · May 16, 2002

Re: Won\'t stay in float!

That is not correct. See if there is something up under the stick that is preventing the stick from going into the detent position for float. Look for wires, wood chips, etc. A call to Power Trac might be needed if there is nothing obvious. Let us know what you find out.

Carpenter · May 16, 2002

Re: Won\'t stay in float!

MR, I know; it worked fine before. I let a friend use my PT, the other day. I wonder what might have happened. I'm going to call PT this afternoon; I'll let everyone know what they have to say. Thanks for the response.

Carpenter · May 16, 2002

Re: Won\'t stay in float!

I talked to Don at PT; he said it's either the linkage or the detent on the control valve. I can probably take care of the linkage myself, but he said if the valve has to be replaced it costs $500!!! /w3tcompact/icons/shocked.gif I sure hope it's the linkage! I'll let you know tomorrow.

MossRoad · May 16, 2002

Re: Won\'t stay in float!

Man, there's gotta be something jamming it. Maybe a wood shaving or rock chip got in around the ball where the joystick mounts on the dashboard. Hopefully just a missing pin or bolt. Wishing you the best of luck!

Carpenter · May 21, 2002

Re: Won\'t stay in float!

I finally got around to checking out the joystick linkage. It looks like the problem is the throw is not quite long enough. There's a nut and a threaded shaft, so there is adjustment. It started pouring rain this afternoon, so I didn't get a chance to try a fix. I'll post the results later.

The nagging question is; how could it work all this time and then suddenly stop? I don't see any way it could loosen on it's own. I did loan it out...hmmm...gremlins...hmmm...bad charma...hmmm...Murphy's Law...hmmm...sabotage by a jealous neighbor...hmm...or maybe just another one of life's unsolved mysteries.

MossRoad · May 22, 2002

Re: Won\'t stay in float!

Where is the threaded rod and nut located? Under the joystick and above the valve?

Carpenter · May 22, 2002

Re: Won\'t stay in float!

Yes it connects the joystick to the plunger on top of the valve. I think if I lengthen it a little it will solve my problem. The joystick stays in the forward position, but dosen't quite engage the float. I'm still not sure how easy/difficult it will be to make the adjustment.

Carpenter · May 22, 2002

Re: Won\'t stay in float!

Well, unfortunately the linkage adjustment didn't work. I guess the detent in the valve is broken. I mowed today with a bungee holding the joystick in float; crude but effective. I think I'll explore other possibilities before buying a new valve. Don said they might be able to repair it, but I think I'll wait until fall ; after summer projects and before the snow flies.

ernemats · May 22, 2002

Re: Won\'t stay in float!

Isn't that covered under power trac's warranty?

Carpenter · May 22, 2002

Re: Won\'t stay in float!

I think the warranty is only for 1 year, and I've had my PT for a little longer than that. I'll check with them and see.

MossRoad · May 22, 2002

Re: Won\'t stay in float!

Bummer /w3tcompact/icons/sad.gif

Did they give any indication as to how much it would cost to repair the valve VS a new valve?

I'm sure, either way, you will have to remove the valve and ship it to them. Did they mention if this will cause air in the system and will the air will have to be purged similar to when you do a hydraulic filter change?

Charlie_Iliff · May 23, 2002

Re: Won\'t stay in float!

Mossroad: you wrote:
<font color=red>Did they mention if this will cause air in the system and will the air will have to be purged similar to when you do a hydraulic filter change? </font color=red>
Since I'm lining up to do my 50 hour this weekend, I've read some of the past discussions, and again talked to Terry Estep, at PT. It is my understanding that air is only a problem on the intake side, where it can get to the pump. On the output side, the air would be pushed through the valve and to the reservoir, so wouldn't be a problem. (That's assuming, of course, that the hose from pump couldn't let air back into the pump. I haven't heard that it could, but I'd be inclined to elevate it and/or cap it to keep it full of oil while the valve is removed, just in case.)

Charlie_Iliff · May 23, 2002

Re: Won\'t stay in float!

Eric:
I hope your 425 is still in warranty. If the detent has failed, it might be something as simple as a broken spring, but I don't know enough about the internals to guess at it. Whether or not it's in warranty, you may want to talk to PT about getting the valve manufacturer to look at it, although certainly PT will want to know what the problem is for future reference.
My recollection is that there was a post some time ago that on rough terrain a 400 series machine sometimes bounced out of float. (PTRich?) Then, Reds reported downpressure on the deck lifting an uphill wheel. The cure suggested was to take it out of float and lift the deck slightly, essentially manual draft control. It sounds as if we have three similar reports. Power Trac is certainly aware of those reports, so it may be worth more calls to ensure that they are working to determine whether it is a general problem or a run of valves, (or, of course, whether the three reports we know about are really caused by the same thing.)

ernemats · May 23, 2002

Re: Won\'t stay in float!

I have also had my tractor pt422 jump out of float on occasion while mowing .

Carpenter · May 23, 2002

Re: Won\'t stay in float!

MR, Don wasn't sure if they could repair it, so no cost figure was given. My main problem, right now, is that I have too many chores for my PT to tear it apart. Everything else works ok, as does the float if I manually hold it in. I'll let you know what happens.

Carpenter · May 23, 2002

Re: Won\'t stay in float!

Charlie,

I'm confident PT will do right by me. My problem is that when you put the joystick in float, the plunger on the valve goes down and then pops back up just a little. If I push the joystick all the way forward, which compresses the plunger fully, the float works fine. I'll be keeping in touch with PT and we'll see what happens.

duane · May 23, 2002

Re: Won\'t stay in float!

Charlie said: It is my understanding that air is only a problem on the intake side, where it can get to the pump. On the output side, the air would be pushed through the valve and to the reservoir, so wouldn't be a problem. (Don't know how to make the font a different color)

The PTO/lift/tilt pump does not seem to call for an air purge, or have provisions to purge air like the variable volume pump. Correct me if I am wrong.

On the variable volume pump, if a hydraulic hose on the discharge side is replaced, then as I understand, no air purge is necessary. The oil return from the wheel motors goes back to the variable volume pump (not the reservoir), so does the air bubble I assume. Not quite sure why this is not a problem. (The discharge of the variable volume pump also goes to the oil cooler and then back to the reservoir, maybe it gets purged via this path?). Just to be safe, should we also go through the purge procedure for items on the discharge side of the variable volume pump?

Duane

Charlie_Iliff · May 23, 2002

Re: Won\'t stay in float!

Duane: Your note
<font color=red>The PTO/lift/tilt pump does not seem to call for an air purge, or have provisions to purge air like the variable volume pump. Correct me if I am wrong.</font color=red>
I think you're right. I should have hauled out the diagram and thought it through before responding. My only thought was, as you noted, they aren't concerned about anything on the discharge side of the variable volume pump, either, just its intake..

Anonymous Poster · May 23, 2002

Re: Won\'t stay in float!

My 422 also failed to stay in float. I adjusted the linkage, which has limited access, and now it works fine. I would double check the linkage.
andrew