RADMAN521 0 #1 Posted April 16, 2010 I am looking at the O-rings under both ends of the hydro's manifold and they're all flat and hard. Could this be the problem why the D won't move any of the hydraulics? Share this post Link to post Share on other sites
rickv1957 72 #2 Posted April 16, 2010 If the O rings were leaking bad enough, pump could possibly not prime up,Rick Share this post Link to post Share on other sites
pfrederi 17,866 #3 Posted April 17, 2010 Keep in mind that the 2 high pressure ports in the manifolds (both pump and motor) use 2 o rings and the top one is a flat profile ring (has a rectangular profile). I would think that if the rings were in bad enough shape to allow prevent the pump from priming itself there would be signs of leakage. When i took mine a part , turned out some "professional rebuilder" according to the PO had used the green O rings used in refrigeration and wrong size to boot...but that was not the cause of my problems...motor was shot. If your mid mount and 3 point are not working well I am afraid it will turn out to be a pump issue The O rings are not a common size (at least not in my set of 1000 O rings) and the rectangular ones are unique. They are still available from Toro and while pricey cheaper than buying 100 each of a couple sizes needed that you have to do from industrial supply places.... Last thought if you think the pump isn't priming open up one of the top plugs pour in some oil and then try her quickly... Share this post Link to post Share on other sites
wh79d160 52 #4 Posted April 18, 2010 I am replacing the o-rings & hydro pump seals on my d160. someone has been in it before & I'm wondering if it was put back together right. Does the back-up oring go in the groove on the manifold first or does the regular o-ring w/the back-up one on top?? Also , when I 1st got my D 3 yrs ago, I was degreasing the under carriage & foung 2 little ball bearings which I know now are the check valve balls on the back of the pump. Don't ask me how they got there but if they were not put back in, would the pump still function ok, which it has other than leaks. Thanks, Tom Perry Ks. Share this post Link to post Share on other sites
pfrederi 17,866 #5 Posted April 18, 2010 The round Oring goes first into the recess (groove)..The rectangular profile one sits on top of that Share this post Link to post Share on other sites
