Another problem
 

Just as I thought I had all the problems fixed on the 680, something else happened. I was mowing with it and wen I was done I noticed spots on the sidewalk were I had backed up earlier. I couldn't figure out what it was. I finally decided to take the tunnel cover off and found out that the one check valve is spitting out hydro fluid, it's the left one if you're on the seat, only seems to leak in reverse. Is the vavle stuck, bad, or bad o-ring? Thank you, all help is appreciated.

It sounds like the valve has gone bad. Swap the valves and see if it happens in the same side or if it will happen with that valve on the right side. If so it is bad. If the same side, something else might be going on.

Just had the same problem on my 1572. I ordered the valves from L & J fluidpower. I have not put them in yet, They were 57.00 each and 5.00 shipping.

Do you have part numbers for ordering from L & J?