HY-3 Pump & Cylinder

I found this to be helpful,

Take special note of the valve return spring and the configuration of the valve itself. Also, it’s not obvious in the picture, but the right-hand stub shaft that holds the driven gear, is 1/2″ diameter. In a Cub Cadet pump, that stub shaft is 3/8″ and the driven gear has a 1/2″ O.D. by 3/8″ I.D. bearing in the gear to fit the smaller shaft. The Wheel Horse pump contains no bearing.
I managed to find a new spring that can be ordered from JC’s Farm &Garden Supply. It is part number 4837 and their phone number is (219) 299 4708. They also carry replacement gears. They have the replacement spring for the pump like the one used on a Cub Cadet as well, Part No. 5281, If you want to order parts from them, just call the number above and leave a message. John will call you back. Do Not use the JC’s Supply website. It belongs to a previous owner and has no connection to the present owner. )
In the picture, the “legs” of the spring are bottomed in the holes they are inserted in and the center of the spring just reaches the top of the valve body. That meant the legs had to be shortened the depth of the slot in the valve body. I used a depth gage to determine that depth and cut off the appropriate length. (Notice the top roll pin extending out of the bottom of the valve body in the picture above. After the center of the spring is “bottomed out” in the slot, that roll pin is driven back in and holds the spring in position.)
I found that a 7/16″ socket worked well for driving the seals into place. As with the Cub Cadet pump, I used two seals.
It’s a little difficult to see, the there still a little of the oil return hole showing. After inserting the shaft, I replaced the cap. There’s no seal. It’s only necessary to tighten the screws to hole the cap in place.

You're a wealth of information lol.

I found it helpful and wanted to share it.

Little mod needed to install the HY-3 on the 1045, an inverted 90 1/8 - 1/4, found at Napa! One Quart Oil Can Made In USA," Tractor Supply", perfect.

Viola! Found the missing rectangular seat! I also broke open a vintage gallon can of IH Red, Valspar. Anyone notice the color match between Rustoleom Sunrise Red, Valspar IH Red?

Those seats are getting harder and harder to find, glad you found one.

me too!