ARK 550 hydro question

[wheelhorse-c-161-1979 117]

I have a Ark 559 on my 1973 auto 18..

The ark operates very well an goes through all the motions.

It lifts very well and the bucket had power in the bucket up mode as well as the bucket down mode.

However the main lifting arms seem to have power only in the lift mode and passively go down without much down strength besides the weight of the whole assembly.

Is that normal by design or are one of my hydro lines not working.

I discovered this the other day when ripping out some bushy vines. I could unearth the vines by lifting them. But when I tried to pull the arm down to pull the vines the arm didn't seem to want pull down with any additional strength besides gravity.

Wondering if any one has thoughts on this.

Thanks!

[AMC RULES 37,134]

It would take modifications to add down pressure on the arm. 

Another cylinder mounted on top of the lifting arms pushing down. 

[wheelhorse-c-161-1979 117]

Thanks for that tip. But why does the two bucket cylinders have push pull power and not the two main hydro arm? Doesn't make sense.

[AMC RULES 37,134]

Does the bucket currently have enough downward pressure to pick it's front wheels up off the ground? 

[wheelhorse-c-161-1979 117]

Yes the bucket will lift the tractor right up without a problem. Nice parking position :)

[KyBlue 655]

I'm not really surprised that it doesnt have down pressure on the lift arms.  In theory you wouldn't really need down pressure ... Angling the bucket would provide the ability to dig in ... So by omitting it they are simply preventing the end user from doing damage to the unit or themselves ...

 

At least that's my logic to it ...

[gwest_ca-(File Mod) 11,079]

A single action cylinder has just one pressure hose. The other end of the cylinder should have a filtered breather that may be plugged and that would slow it down. Just guessing as I've never had a fel.

 

Garry 

[pfrederi 17,787]

To be clear when you lift th front of the tractor are u using the lift arms (rear ones) or the curl arms the forward pair. 

[wheelhorse-c-161-1979 117]

I just pulled out this pic from last spring to illustrate where the hydraulic power is.  This should help illustrate the issue I noticed.

Bucket movement up and down is fine.  But the lift arm seems to have power up only, and only gravity drop or minimal down power.  So I'm thinking that something might be wrong with the lift/drop hydro circuit?

 

[boovuc 1,090]

I'll have to fire mine up tomorrow after work and check my lift arm's abilities to pick the front-end up. I'm thinking I can on either the curl or lift arms put I want to be certain. I know that when I lift or drop my lift arms, you can hear the engine grown a little which tells me it is forcibly lowering the arms.

 

On second thought, I know my lift arms have significant down pressure. I can lift the whole tractor's front off the ground even with the bucket in float. Trying to level that wet modified stone last week after I put the duels on it, I had the bucket slightly curled down into the pile then hit my lift arms down so that the whole front end was off the ground while I scooped/leveled the drive.

Something isn't correct with your 559 setup.

Edited September 29, 2014 by boovuc

[wallfish 17,055]

It's hard to see from the pics but the original cylinders should have 2 hoses connected to each end which means a double acting cylinder. You should have down pressure on the arms. There is a float position on that spool of the valve so if you move the lever all the way, it will float the arms by allowing fluid to pass without pressure. Very useful when doing things like moving snow so it will follow the contour of the ground without digging in or lifting your tires. Try moving the arms down slowly, without moving the lever all the way and see if they lift the tractor. You should also feel a slight click from the detent ball in the handle when it passes into float position. The detent will hold the handle in the float position.

[wheelhorse-c-161-1979 117]

Thanks boovuck and John.

Yes the setup is original cylinders wih two hoses on each.

I will fire up it up on Wednesday and try to test the down push by moving the lever slowly. I didn't realize that pushing the lever all the way would float the arms with a fluid bypass. I'm willing to bet that's exactly what I was doing when I was trying to rip down the vines. I think I had the lever pegged in the full down position which would explain why it wasn't working as expected.

Thank you so much for the insight!

Bit by bit my auto 18 is coming back. Looking and working better. Over the summer I had the sunstrand tranny rebuilt by David L. (A longstanding forum member) He did a masterful job. I just had new counterweight brackets welded to replace the old rusted out ones. Now the weight box is nice and secure. Upgraded the front axle to a 1" spindle. Reinforced the front bucket with welded steel plates as it was a bit flimsy.

Soon I'll probably get to the point where she'll be worthy of new Wheel Horse stickers:)

Best,

Jack

[pfrederi 17,787]

Thanks boovuck and John.

Yes the setup is original cylinders wih two hoses on each.

I will fire up it up on Wednesday and try to test the down push by moving the lever slowly. I didn't realize that pushing the lever all the way would float the arms with a fluid bypass. I'm willing to bet that's exactly what I was doing when I was trying to rip down the vines. I think I had the lever pegged in the full down position which would explain why it wasn't working as expected.

Thank you so much for the insight!

Bit by bit my auto 18 is coming back. Looking and working better. Over the summer I had the sunstrand tranny rebuilt by David L. (A longstanding forum member) He did a masterful job. I just had new counterweight brackets welded to replace the old rusted out ones. Now the weight box is nice and secure. Upgraded the front axle to a 1" spindle. Reinforced the front bucket with welded steel plates as it was a bit flimsy.

Soon I'll probably get to the point where she'll be worthy of new Wheel Horse stickers:)

Best,

Jack

If the lever stays in the full down position it is in float.  No down pressure.  You should be fine if you just move the lever ahead a little bit.

 

Note:  I have found that when I try to raise the bucket very slowly e.g. just pulling back very slowly on the lever to avoid  any jumping the bucket will settle a bit first .  I asked the hydraulic repair place and they said it was normal, the valve is designed that way.  You have to get adept at moving the lever fast enough to avoid the settling but slow enough to avoid jerking up....

[boovuc 1,090]

Glad the Auto is getting there. It looks great from the pics you posted. I'm happy to hear that there still are Sundstrand folks still practicing their craft as it is hard to find anyone who will work on them and the parts are getting harder to find though they are out there.

Please let us know how it went!

[wheelhorse-c-161-1979 117]

Thanks BooVuc,

I certainly will. And I do have to say that David L from this forum who rebuilt the hydro is a true talent, meticulous like I have rarely seen and very fair for the quality work he performs.

I'll get some newer pics together with the improvements. I'd like it to be a show piece, but for me this tractor is a true work horse for my small goat farm so for now I'm focusing on rebuilding functionality before I worry about the carnuba wax:)

Best,

Jack

[MalMac 1,331]

wheelhorse-c-161-1979, one word of caution here. When I was cleaning out my daughters goat pin using my C-141 with a Ark on it. In the short time I was off the tractor on the end of a pitch fork, a goat ate off one of the valve stems on a front tire as I had the wheels turned and presented the irresistible valve stem to it. Then one jumped up on the seat and started to do a number on the on the rubber lines running into the Control Valve. Don't turn your back on those destructive Horse eating creatures for one second.

[Forest Road 594]

I've used several loaders with tires valves. On most when you push down you'll feel a "click" or detent and push further down. That's your float position which lets bucket go down with gravity. Often the valve gets worn and when you push down it goes right to float. This may be your problem.

When is the last time you checked your hydraulic fluid level? If its low that could also contribute to your woes.

Edited October 1, 2014 by Forest Road

[wheelhorse-c-161-1979 117]

Well, you were absolutely right. When the down lever is push fully it goes to bypass mode and the arm just lowers by gravity. Hydro power is engaged when not fully pushed all the way. Thank you….   So after a week of working great moving a chunks of a giant old oak, now I have the next problem to fix.

 

The clutch engaging the ARK 550 hydro pump is probably worn out.  Details in my next fresh post.

[boovuc 1,090]

Yowsa! I'll bet that chunk of Oak is is a good 200 to 250 lbs!

[wheelhorse-c-161-1979 117]

Some were more like 400 lbs or so. Worked like a charm. Engine barely changed rpms.   Of course now new problem I just posted. The FEL pulley/clutch stopped working so need help there.  Details in another post I just put up

[JoeM 7,874]

Keep in mind, the cubic inch displacement is much less on the down side, of the cylinders, as compared to the lift side. Probably 30% of, so the down force will only be 1/3rd of the lift at the same pressure. You could tee in a pressure gauge at the cylinder to make sure there is full pressure.