General Pump YU 5221 Unloader Rebuild.

[Greg Pack]

Hi Guys,

I have these large General unloaders on my water wizards. They are around $275 new. The kit to rebuild them is around $60. However, all the unloader issues I have had was because they were leaking, and also allowing air into the system making the pump run rough.

A couple of years ago a service guy showed me that really two small o rings that can be easily replaced was the cause of the leak. The O rings were fairly common O rings. I haven't had luck finding them a lowes or home depot but a lot of smaller mom and pop stores had them. So for just a few dollars and less than half an hour you can stop the leak.

Does this interest anyone? If so, I'll get more specific about the repair and post the proper size orings.

 

[vinh]

definitely. Just replaced a leaking unloader with a used one.

Did you find the part number and where to buy these O rings. can these O-rings be changed with the unloader still attached to Cat pump?

Hi Guys,

I have these large General unloaders on my water wizards. They are around $275 new. The kit to rebuild them is around $60. However, all the unloader issues I have had was because they were leaking, and also allowing air into the system making the pump run rough.

A couple of years ago a service guy showed me that really two small o rings that can be easily replaced was the cause of the leak. The O rings were fairly common O rings. I haven't had luck finding them a lowes or home depot but a lot of smaller mom and pop stores had them. So for just a few dollars and less than half an hour you can stop the leak.

Does this interest anyone? If so, I'll get more specific about the repair and post the proper size orings.

 

[MEP001]

I've rebuilt them still on the pump, but you usually have to remove the bypass hose and fitting to push the parts out of the body to replace the o-rings. They aren't a custom made size, so it shouldn't be a problem finding replacements.

 

[Greg Pack]

Did you find the part number and where to buy these O rings. can these O-rings be changed with the unloader still attached to Cat pump?

I got all the orings you need at Valleydale. I bought bags of them from either Zoro or McMaster Carr. Just give me a shout. Yes, you can remove the guts and rebuild without removing the entire unloader. I actually just keep an extra one rebuilt ready to swap.

 

[toddmullens]

I got all the orings you need at Valleydale. I bought bags of them from either Zoro or McMaster Carr. Just give me a shout. Yes, you can remove the guts and rebuild without removing the entire unloader. I actually just keep an extra one rebuilt ready to swap.

I am working on getting a custom made spring to use in these unloaders made out of stainless so when it does leak, the spring will not rust up and lead to more oring failures. I will post back when I get the quote. I am sending in an original spring for the spring company to get the proper specs.

 

[toddmullens]

The stainless springs are being made and should be delivered to me within 2 weeks. If anyone is interested in purchasing some, let me know. I had around 40 made and will only be using 22 or so. These springs will not rust and will increase the life of the o-rings. My cost on the springs are around $40 each.

 

[MEP001]

Have you tried this regulator?

https://www.kleen-ritecorp.com/p-17...pressure-regulator-valve-53-gpm-2900-psi.aspx

You shouldn't need an unloader unless the pump runs at some point with no water flowing from the machine. I used to replace the YU 5331 unloader on the D&S 5000's with this one and they would last at least twice as long.

 

[toddmullens]

Have you tried this regulator?

https://www.kleen-ritecorp.com/p-17...pressure-regulator-valve-53-gpm-2900-psi.aspx

You shouldn't need an unloader unless the pump runs at some point with no water flowing from the machine. I used to replace the YU 5331 unloader on the D&S 5000's with this one and they would last at least twice as long.

Do you use this on cat3535 pumps?

 

[MEP001]

Yes, I also use it in place of the pop-off valve on the Vectors because it's about half the price and lasts practically forever since no water goes through it.