Rebuilding Ark 550 loader cylinders

[JackC 617]

I reinstalled the spool valve and adjusted the PTO on the D-200. The PTO adjustment was way off and was not spinning the pump properly to operate the loader. The loader now works perfectly.  The cylinders also hold the position of everything overnight. 

 

Here is the PTO adjustment mechanism and the procedure is in the service manuals. The service manual also recommends and annual cleaning of the PTO.

 

 

[Texas Todd 1,025]

Great thread. I am having the same problem with my bucket not staying in the upright position. I have the tilt cylinders off and have the snap rings off.  Is there a trick to getting the piston out? I put the pin back in and tapped with a hammer but its not moving. Thanks for any advice!

 

[82Caddy 851]

Clean the end with the snap ring.  They tend to get crud built on on them.  You can also gently use the piston as a slide hammer.  Slide it in a bit (couple inches) and then pull forcefully out.  Watch out for flying hydraulic fluid/oil.

[Texas Todd 1,025]

Okay. It sure looks like the washer is a bigger circumference than the end of the cylinder, but yet that doesn't make sense! Will give it another go. Thanks!

[Texas Todd 1,025]

Okay, I guess I just wasn't holding my mouth right. Got it out. Is it just these two O-rings? I don't see anything else...

I see one spot where it looks boogered (yellow arrow in the vicinity)

 

 

 

 

[82Caddy 851]

Yep, those two o rings and there is another inside the part with the yellow arrow.  Check the cylinder ram for pitting as well.  It'll tear the o-rings after a few passes over it.

[Texas Todd 1,025]

Found it.

Also found the culprit.

 

Edited March 29, 2017 by Texas Todd

[Texas Todd 1,025]

Back in business. Replaced the four o-rings with four of these, as these were the closest I could find. And looked really close.

Also used a Metric 214 O-ring for inside the piston base, because that's what I had and it was pretty close.

 

Seemed to work fine. Will see if it holds up over time.

 

I have some of that hard to lift once the oil gets warm, so I am going to try the PTO adjustment and see if that fixes it.

 

Thanks guys!

 

Edited March 29, 2017 by Texas Todd

[82Caddy 851]

Glad you got it sorted out. Might be worth the time to order/buy enough to do all the cylinders. 

[Texas Todd 1,025]

My intention was to get all 8 at least, but the best Hardware store in this area had 4..... But I will get em and have em on hand in the near future. 

 

Like everyone says....its much easier than I suspected.....the great unknown.....

Edited March 30, 2017 by Texas Todd

[82Caddy 851]

Be sure to check the local hydraulic shops. Those o-rings are pretty generic items. My local FleetPride (formerly CatCo) had all of the o rings I needed in stock and they were cheap. Like sub 5$ to do all 4 cylinders plus have some extras. 

[Texas Todd 1,025]

Well, the bucket now holds tilt and lift and doesn't bleed off, but it won't lift any weight. It also won't pick up the front of the tractor unless I "bump" it up. Meaning lift, stop, lift stop. The pump builds pressure and it will lift about an inch and then stop until I let off and wait 1 second or so and bump it again. I noticed the belt was slowing way down when it is under strain. When I let off, the belt spins back up (building pressure) and then after a short bump the belt slows again. It does seem to have more lift power using the tilt cylinders, it will raise the tractor, albeit very slowly using the tilt cylinders but not the lift cylinders without bumping.

 

The history on this loader was I bought it and the tractor it has always been on and got it mounted back up. I routed the return hose wrong and the pulley sliced it. Replaced the hose with a tractor supply hose and that's when I noticed the tilt bleeding off. The manual called for Type A Power Steering Fluid or No. 5 hydraulic oil. I couldn't find either of those and did some searching on here. Discovered the same model pump and apparently same year (1974) also called for 10w-30 as an option so that's what I replaced after the hose change and tilt cylinder repair.

 

I am open to suggestions. Bad pump, wrong fluid? 

[pfrederi 17,739]

Did you clean out the suction screen??

 

Pump may not be able to get fluid fast enough

Edited April 1, 2017 by pfrederi

[82Caddy 851]

Belt could be slipping too. Might need to check PTO engagement. Since you switched to motor oil, could need another flush to make sure there isn't any of the old fluid still in it. 

[Texas Todd 1,025]

Well, after you try everything....try it once more.  I adjusted the PTO (again) and made it tighter than Dick's hat band and I am back in business! Literally took another couple turns of the turnbuckle to make it work like it should.  I am going to change the oil in it every hour or two of use a couple more times to make sure I just have 10w30 in it.

 

Man it feels good when you finally get a win!!

 

Thanks guys!

39 minutes ago, pfrederi said:

Did you clean out the suction screen??

 

Pump may not be able to get fluid fast enough

Is the suction screen on the left side of the pump (driver's side for lack of a better descriptor)? It doesn't have a filter in-line, which may not be a bad idea to install.

Edited April 1, 2017 by Texas Todd

[pfrederi 17,739]

the suction screen is actually mounted inside the reservoir (drivers side stanchion) you get to it when you remove the suction hose.  If you mount a filter on the suction line it has to be a special one (basically another coarse screen).  i prefer to use a hydraulic filter on the return/bypass line.  Then you can use 10 micron paper filters.  Consider the hydro system on the tractor itself.  There is a screen filter on the suction line (In the transaxle) and the 1410 spin on filter is on the return side.

 

Please no comments about my return filter re fittings are what I had lying around and the Fram was the only one the parts store had in stock that day...

Edited April 1, 2017 by pfrederi

[Texas Todd 1,025]

10 minutes ago, pfrederi said:

the suction screen is actually mounted inside the reservoir (drivers side stanchion) you get to it when you remove the suction hose.  If you mount a filter on the suction line it has to be a special one (basically another coarse screen).  i prefer to use a hydraulic filter on the return/bypass line.  Then you can use 10 micron paper filters.  Consider the hydro system on the tractor itself.  There is a screen filter on the suction line (In the transaxle) and the 1410 spin on filter is on the return side.

 

 

 

Awesome. Thank you sir!