Ark loader spooler

[jverhaag 10]

The old girl is down. While she is down with an engine issue (see 4041 won't start for that story) I think I will address another issue at the same time. She has a ark loader. The bucket drifts down regardless of a load or empty. It's much faster when loaded. Additionally when picking up a load I may need to pull the lever back and forth several times before she starts to rise. She comes up slowly until she hits the second stage and then rises quickly. I put a new pump in it last year after discussing it here with the group. A local farmer told me it may be the o rings in the spooler and the pressure is blowing by the o rings. I know nothing about hydraulics.

Would the group agree with this assessment. Anyone know the parts numbers or sizes?

[country 0]

I'm not a hydraulic expert, but leak down could be through the spool valve or the cylinders.

[phillobbezoo 139]

Depending on what cylinders are on it I would bet it's the cylinders to blame, I rebuilt a set on an ark 700 that settled, the o-rings were bad replaced them and it was like new.

[ShaunE 1,271]

I have rebuilt all four of my cylinders & spool valve. They are fairly simple but it's a messy job.

There is a place in Rockford IL. called Great Lakes Rubber. They have every O-ring in the world & are very reasonable. If you have replaced the pump with the correct output substitute & the belt is not slipping, the problem should be in the cylinders & or spool valve.

Be careful when removing the end caps of the spool valve as there is a spring & two detent balls that ARE going to fly out if you're not prepared. Remove the levers & the end caps & the shafts will slide out the rear. There will be four small O-rings per valve. Two on each shaft & two inside each end of the housing. Eight in total for the entire valve. All are the same size.

Cylinders are the messy part. Remove them from the loader. Then remove the 90 degree fitting from the rod end into the cylinder. If you do not remove this fitting, it will NEVER come apart. Next remove the snap ring on the rod end. When removing the rod, use it like a slide hammer to remove the rod bushing & rod. There should be three O-rings. Two larger externally & one smaller internally between the rod & rod bushing.

I know it sounds complicated but its really just very messy. While you are doing this, you may want to consider adding a screw on replaceable filter on the low pressure side of the spool valve. Very cheap & easy. There is an old post showing one.

Good Luck

[jverhaag 10]

Thank you Shaune for the detailed instructions. Your right, that sounds intimidating as hell.

But I teach middle school. If I can handle 140,12 years old, five day a week I can rebuild a cylinder

[JP 0]

this thread caught my eye.... I was working the 620/ARK 700 & brantly pretty hard on a project. I noticed the bucket slowly 'drifting'. I have rebuilt the loader cylinders a few times, never the bucket. Took apart the bucket cylinder & the piston o ring was totally gone. Today I'm off to see the hydraulic o ring guy.

JP

[isetta 50]

JP can we get some pics of your machine with loader and backhoe?

[JP 0]

I will attempt when I get the hydraulics done.

When I did the other cylinder, half an o ring fell out....

Gotta love the ARK loader!

[ShaunE 1,271]

You're welcome jverhaag. You are a saint for teaching junior high kids. The're alligators!

isetta is the one who posted the spin-on filter addition. I added one to mine but the pictures on this site are of his loader. I did mine virtually the same way with a slight mod as his post on the filter addition is on an Ark 600 loader & the one I added is on an Ark 700 loader.

I should also mention, if you have a dentist visit planned in the very near future, ask your hygienist for a few of their old cleaning picks. They make the BEST O-ring removers.

Keep us posted on your progress with your hydraulics.

[jlasater 285]

On my John Deere 40C dozer, someone replaced the cylinder piston seals with O-rings, except they were smaller than the pistons so they didn't even touch the cylinder walls. $20 for a set of the proper seals and it works fantastic. Previously, it floated constantly.

[jverhaag 10]

The bucket seals caused the drift? I would never have considered that. Although it's all one sealed system I guess that makes sense.

So please correct me here. The pump pressures the system and the spooler routes the pressurized fluids to the cylinder in question/ demand. If that is in fact the case, a leaking o ring anywhere in the system, on any of the cylinders could be causing the drifting issue or the slow lift. Correct?

[JP 0]

I would venture, Yup. Replacing the o rings is 'Jim Proof'. I would take one apart, find a local hydraulic o ring guy. Get them matched up. Then replace them all. Then you will know if you need to to take apart the spool valve.