425 again…movement problems…

[Modrob]

Our old 2001 425 (Kohler CH25) has been doing fine since repairing the last issue. Now it has started having terrible trouble moving—reverse is struggling, and while trying to back up a small flat trailer with it on a slight incline, it struggled more and eventually stops moving. But whines quite loudly in reverse. Even when it has stalled movement. I believe forward has a little trouble, but overall much better, and no whine…easing downhill now then letting off pedals it will whine and still moves unless I tap on the reverse pedal which will stop it, but not for long…
Oil/fluid is good, maybe 6-7 hours since last change.
I recently jacked it up all around and tested treadle pedals. Worked fine and no noise heard from any motor…
???

 

[m5040]

Did you bleed air out after the oil change? When in reverse/stalled and you hear the loud noise from hydraulics, is the engine at high RPM and no load or heavy load?

 

[Modrob]

Yes. After the fluid change I did bleed it…this was several months back and other than some other motor issues I had (that saga elsewhere here ) it has worked just fine. This seems to have started recently and kind of snuck up on me…
The noise—it happens at high or low throttle, loaded or unloaded. But it is slightly worse with load. (I used it again today and intended to get video to post, but in my haste I forgot to choose VIDEO, and ended up with one picture LOL)

 

[Modrob]

Had a few buckets of dirt today and was dumping onto a little hill. As I’d let off the forward pedal and the momentum would carry me forward the noise would happen while it was moving forward, no pedals. Seems like it doesn’t hold back like it had been before…

 

[MossRoad]

So if you abruptly let off the directional pedal while moving at a decent speed, it doesn't abruptly stop? It rolls a ways?

 

[2manyrocks]

Do you have a leak somewhere that is allowing the system to suck in air?

Look in your hydraulic oil tank for air bubbles.

Total hours on your machine?

 

[Modrob]

So if you abruptly let off the directional pedal while moving at a decent speed, it doesn't abruptly stop? It rolls a ways?

Not on level ground. On slopes it wants to keep rolling, with almost no resistance —I have to keep stabbing at the reverse pedal to stop it going downhill. On level ground forward at speed, suddenly let off the pedal, and I get a very quick/split-second whine/noise, and stops normally.

 

[Modrob]

Do you have a leak somewhere that is allowing the system to suck in air?

Look in your hydraulic oil tank for air bubbles.

Total hours on your machine?

Not that I know of, but I’ll check again…hours? Oh boy! This machine has had a hard life from 2001 up to about 2016, and I’ve been fairly gentle with it since 2020…

 

[ponytug]

Whines from hydraulic pumps or motors is not generally a good thing. I'd be checking for air leaks, bubbles, and then pulling the filter and cutting it open to check for any metal pieces.

All the best,

Peter

 

[Modrob]

Dang! I was making a video clip of it acting up…turns out I had it in photo mode!
Decided to use it to shovel/scrape snow off the sloped driveway…it got the job done but struggled. I think the problem is more pronounced in reverse mode…and for some reason (this has been happening now for quite some time and honestly I just hadn’t had the time to dig into it) I have to keep throttling up…push up on the throttle handle and within 30 seconds or so, have to bump it up again…over and over. I need that full throttle for this hill we’re on. I need to figure out what holds that throttle setting—spring? Or the friction of the cable itself?
And…I really need more room to get it inside out of this freakin’ cold and snowy weather so I can dig a little deeper without suffering near frostbite
I’ll get a pic of the throttle/carb setup shortly and post…

 

[ponytug]

FWIW: The throttle cable handle has a friction plate with an adjustment in it on mine. (Under the dash)

All the best, Peter

 

[Modrob]

FWIW: The throttle cable handle has a friction plate with an adjustment in it on mine. (Under the dash)

All the best, Peter

Ah! I might have seen that once before but it was long time ago and so many things today cloud my feeble brain…

 

[ponytug]

Ah! I might have seen that once before but it was long time ago and so many things today cloud my feeble brain…

Believe me, I know the feeling.

We have club mugs available on Amazon and other fine retailers.

 

[m5040]

The throttles appear to be on the inexpensive side. I have to do mine also and have put it off cause it still works most of the time. I don't like to run at full throttle, and the throttle holds better at midrange RPM unless I hit with hand as I steer.
I was wondering if you could sneak a wrench through the slot and tighten a nut at the pivot??
I should get serious and at least look at that, but its COLD.

Any chance you have a noncontact thermometer? They used to sell for close to $20 at Harbor Freight. It may help you to check the temps of each wheel motor and compare to each other. Looking for a hot(ter) one that indicates bypassing oil.

 

[Modrob]

The throttles appear to be on the inexpensive side. I have to do mine also and have put it off cause it still works most of the time. I don't like to run at full throttle, and the throttle holds better at midrange RPM unless I hit with hand as I steer.
I was wondering if you could sneak a wrench through the slot and tighten a nut at the pivot??
I should get serious and at least look at that, but its COLD.

Any chance you have a noncontact thermometer? They used to sell for close to $20 at Harbor Freight. It may help you to check the temps of each wheel motor and compare to each other. Looking for a hot(ter) one that indicates bypassing oil.

“…sneaking a wrench…” now that, I’m not sure of. My first thought is probably not from what I remember last time I had that top tunnel/mount plate off…I’m thinking awfully tight space but could be wrong. I think I’d rather just go ahead and pull it off and have another closer look—the choke handle keeps sticking after a while of sitting so I’m sure it needs attention as well. And yes, it’s COLD…too danged cold LOL. I don’t do bad with it when I finally decide I have to go out in it and shovel snow or the like. Then, I get heated up and have to start peeling clothes.
AND…how about this for luck—I just today received a laser thermometer from UPS! I’ll give that a try soon. AFTER it gets less COLD.

 

[ponytug]

As @m5040 mentions, with a thin wrench I can do it on mine from the top, but I have always done it by reaching up from underneath, and looking through the slot. It may take some fiddling because if you get it too tight, moving the throttle is a wrestling match. Not hard, just fiddly. I like to clean, grease, and then adjust, as the slot is an invitation for dust and debris to settle into the sliding mechanism, and in my experience, it is always filthy.

All the best,

Peter

 

[Modrob]

Dang!…had to fire it up last two days to clear off snow…Brrrrrr COLD! I’m OVER this snow crap So I just had to contend with constantly pushing up the throttle to get done and get back to WARM and thaw out my frozen toes Maybe we’ll get a warm spell and I can dig into this again.
Again, very sluggish moving but I believe it’s more in reverse along with the noise.
That swivel joint on top of the pump area—it seems to me to be good, in that from its center resting position if slightly pushed one way or the other it starts to have effect…in other words don’t appear to have any slop there. Could it be that over time the whole system from pedals up could be out of alignment? As in right or forward pedal has more travel result than the left reverse pedal? Plus, I’m starting to think the noise (loud, shrill rubbing/grinding, constant and more intense the more the pedal is pushed) when reversing might be coming from the pump area. Doesn’t do it when I had it jacked up all around but when I’m in the seat and moving it, I hear it—just can’t get my ears that far back there when I’m operating

 

[m5040]

Just and FYI, if the engine RPMs are too low for the driveline load, they all make a hydraulic wine noise from the pump that gets louder the more you push the treadle pedal down.

 

[Modrob]

Just and FYI, if the engine RPMs are too low for the driveline load, they all make a hydraulic wine noise from the pump that gets louder the more you push the treadle pedal down.

Hmmmm…interesting. Best I can recall I don’t think I’ve had many occasions of running it at low rpms—it’s usually cranked up…at least all the times I’ve heard it so far. I’m gonna try in the next few days to get some video of it when it’s happening.

 

[ponytug]

Dang!…had to fire it up last two days to clear off snow…Brrrrrr COLD! I’m OVER this snow crap So I just had to contend with constantly pushing up the throttle to get done and get back to WARM and thaw out my frozen toes Maybe we’ll get a warm spell and I can dig into this again.
Again, very sluggish moving but I believe it’s more in reverse along with the noise.
That swivel joint on top of the pump area—it seems to me to be good, in that from its center resting position if slightly pushed one way or the other it starts to have effect…in other words don’t appear to have any slop there. Could it be that over time the whole system from pedals up could be out of alignment? As in right or forward pedal has more travel result than the left reverse pedal? Plus, I’m starting to think the noise (loud, shrill rubbing/grinding, constant and more intense the more the pedal is pushed) when reversing might be coming from the pump area. Doesn’t do it when I had it jacked up all around but when I’m in the seat and moving it, I hear it—just can’t get my ears that far back there when I’m operating

Depending on the control system you have, they all can go out of alignment.

As @m5040 mentioned a certain amount of whining at low oil temperatures is to be expected to happen due to higher oil viscosity, but try to minimize it by letting the oil warm up. I believe that @MossRoad starts his and lets it run for a while (15 min?) while he does some hand shoveling. If your pump is not in trouble, the whining sound is the oil cavitation as it is being pump and the cavitation is very hard on, and damaging to, surfaces.

All the best,

Peter