What causes a Hydro Transmission to go?

[nekovt 0]

Hi Everyone, I just bought a 1988 518-H w/an 18 HP Onan Engine for $175. The place that sold it to me said that the Hydro pump (And Eaton 7) was replaced about 2 years ago, I'm guessing that was at about 650 Hours.

The reason I ask is that I have a 314-A that was given to me which has 1600 hours on it. The original owner said that the pump started to slip at about 1200-1400 hours.

what I'm wondering is why would an Eaton 7 start to die at 650 or so hours?

I've heard that you have to run them at high RPMs. Is it true that low RPMs damages the pumps? I'm just suprised that the 518-H pump only got 1/2 the hours.

The other question I have is I was able to get a transaxle with an Eaton 10 Pump. I'd like to know if I can by pass the lift valve. I would simply loop back the oil filter to the transmission again. Is this possible?

Thanks!

Brad

[WH nut 553]

You should have no problem looping the lift valve. Its an open center valve, meaning there is fluid passing through the valve at all times until the valeve is shifted. So it has to be looped if it isnt run through the valve