Ark 508 loader pump

[prondzy 3,867]

So i have been searching with little luck. I have an Ark 508 and the original cessna pump crapped out the other day. Don't question the pump i know its bad. What have you guys replaced your pumps with? Do you have a link or could you pm me with the punp and model #.

 

 

All help is appreciated 

 

[rmaynard 14,888]

I can't help you with a direct answer, but I have a 508 and I need the 5-1/2" OD pulley that goes on the 9/16" shaft. Impossible to find. However, there have been some threads on here about guys replacing or using pumps from Surplus Center. I'm sure some details can be found if you do a search.

 

 

 

 

 

Edited February 2, 2017 by rmaynard

[MalMac 1,328]

There's a lot of different places that sell what you need. I believe Eaton acquired Cessna. So try and find a Eaton pump dealer and take your pump in. Good chance they can match it up. I am sure there are also cheaper alternatives out there like mention with Surplus Center, Northern Tool,etc...... but if you don't know the particulars to your pump then you might have to take to a hydraulics shop to let them identify it.

[prondzy 3,867]

4 hours ago, MalMac said:

There's a lot of different places that sell what you need. I believe Eaton acquired Cessna. So try and find a Eaton pump dealer and take your pump in. Good chance they can match it up. I am sure there are also cheaper alternatives out there like mention with Surplus Center, Northern Tool,etc...... but if you don't know the particulars to your pump then you might have to take to a hydraulics shop to let them identify it.

I took the pump to a good hydraulics shop who have helped on some sundstrand questions and they were suprised to see such a small pump. Unfortunately after a couple days of research they came up with no alternative pump. Im having a tough time figuring out psi and gpm output of the old pump to find a comparable model 

[roadapples 6,981]

I`m thinking John  @wallfish might be able to help...

[MalMac 1,328]

I was thinking same thing wallfish should be able to jump in here. I would think that hydraulic shop should be able to identify it and recommend a replacement. I myself would question their ability if they could not come up with a pump for a simple front end loader. It's not like your asking something to control the space shuttle here.

[smoreau 658]

6 gpm pump and you pressure should be controlled by your pressure regulator in your control valve. It is a simple open center setup that works well for this system. Make sure you flush all the lines, tank its and use fresh oil with a new hart for your loader. 

[bmsgaffer 2,043]

On 2/2/2017 at 2:14 PM, rmaynard said:

I can't help you with a direct answer, but I have a 508 and I need the 5-1/2" OD pulley that goes on the 9/16" shaft. Impossible to find. However, there have been some threads on here about guys replacing or using pumps from Surplus Center. I'm sure some details can be found if you do a search.

 

I am not educated in this much at all, but for finding hard to get pulleys would something like THIS plus THIS work in your case? Always wanted a loader but will likely never have the space for one so I have been learning from afar only.

[rmaynard 14,888]

8 hours ago, bmsgaffer said:

 

I am not educated in this much at all, but for finding hard to get pulleys would something like THIS plus THIS work in your case? Always wanted a loader but will likely never have the space for one so I have been learning from afar only.

It just might. I will have to take a closer look. Thanks.

[rmaynard 14,888]

Having looked at the spec page, the pulley would work, but the dimensions of the keyway on the hub look too large, and there is no set screw. I have emailed customer support for more details.

[gwest_ca-(File Mod) 10,491]

If it has just two 1/4" bolts to pull it together or push it apart it should be a type G or H. You have to use a matching type of sheave. There is no set screw and the 9/16 shaft should have a 1/8" x 1/8" key x the length of the bushing.

When the bolts are torqued to the spec the manufacturer specifies it will be locked on the shaft. 

 

http://www.leeson.com/Sheave/USSheavesCatalog12Pg1to84_smeffective1-1-13.pdf

See page 16.

 

Garry

[rmaynard 14,888]

Thanks Garry. Just goes to show that an old dog like me can learn a new trick. I little further investigation is in order.

[wallfish 15,918]

On 2/2/2017 at 2:07 PM, prondzy said:

So i have been searching with little luck. I have an Ark 508 and the original cessna pump crapped out the other day. Don't question the pump i know its bad. What have you guys replaced your pumps with? Do you have a link or could you pm me with the punp and model #.

Here's a comparable pump. This is the same pump recommended by PF engineering for their loader and backhoe build pumps. Used this one for the backhoe and have never had an issue so if or when the loader pump lets go, this is what will replace the original Cessna pump on mine.

http://www.northerntool.com/shop/tools/NTESearch?storeId=6970&ipp=24&Ntt=517+hydraulic+pump

 

Here's a pulley calculator to help determine what size since RPM of the pump directly relates to the GPM output of the pump. I use 1:1 and run the pump at 3600 RPM

http://www3.telus.net/findNchoose/pulley_calculator.html

[wallfish 15,918]

@rmaynard that pulley hub gaffer posted should work. Also known as split taper bushings but the "taper" refers to the pulley/sheave engagement and not the shaft bore. If the key size  IS different, you can always shape one to fit. Those hubs lock onto the shaft pretty good all on their own so a slightly mis-shapened key should not really be a problem at all. The picture they use is all the same one for most of those sizes so it's not an actual part pic, which is why the key way appears bigger but it never hurts to ask and be sure.

[rmaynard 14,888]

Thanks for that info John.

[prondzy 3,867]

Yes thanks John you have been a huge help!