PT422 "hydroback" adjustment?

ldabe · Nov 20, 2021

Good evening fellow PT'ers. I have installed a new 22hp Robins engine, and shortly will have to adjust the hydroback. According to Terry at Power Trac he says I will have to jack the tractor up to get it off the wheels to do the adjustment.

Has anyone done this before?
If so, could you step me through how you did it?
If so, do you have any tips or tricks on the procedure?

As usual, thanks in advance for any and all help.

smilindave · Nov 26, 2021

if you didn't remove it from the top of the pump, you may not need to do anything. been a few years since i replaced mine, but if i remember, you need to loosen the nut on the shaft and then rotate the black tube as needed. The wheels will stop turning when the adjustment is correct

ldabe · Nov 26, 2021

smilindave said:
if you didn't remove it from the top of the pump, you may not need to do anything. been a few years since i replaced mine, but if i remember, you need to loosen the nut on the shaft and then rotate the black tube as needed. The wheels will stop turning when the adjustment is correct

Smilindave, thanks.
Yes the hydroback was removed. I have it connected back loosely, and will try to adjust it when I get all wheels off the ground.
I still have not started the new engine yet. I had purchased a new harness, but it's wires are of different colors than the old, and I am trying to make sure all connections are correct before I hook up the battery and start the engine.
I sure don't want to mess up the engine.