Exmark Viking hydro gear BDP-10A leaking

Discussion in 'Mechanic and Repair' started by Roger, Apr 8, 2014.

  1. Roger

    Roger LawnSite Fanatic
    Messages: 5,943

    My very old Exmark Viking has one pump that has started a leak at the bypass valve lever.

    This pump has 1,000s of hours, perhaps 8, and has been solid. The counterpart pump on the other side was replaced in 2008.

    I did not have a leak when finishing the 2013 season. But, I had the mower out a few times over Winter, running to warm up, a few passes around the drive. I had opened the bypass valve so that I could push/pull it into a Winter parking spot in the garage.

    A couple of weeks ago, I had it out running, doing some maintenance work. I noticed a drip under the valve, the oil on the engine deck. Today, I took it out for the 2014 season for the first time. I finished one job, went to the next, and noticed a considerable amount of oil on the deck. I watched closely and a drip was happening about a 30 second interval. This means it is substantial, and will loose considerable amount of oil over a day's work.

    I am in a quandry. The machine is 18 years old, engine still in pretty good shape (uses a little oil, but runs well -- a 15 hp Kohler, single cylinder). The other pump was replaced in 2008, but neither wheel motor has been touched. I always consider the pumps and wheel motors as the most vulnerable for failure.

    I believe the original pump is a Hydro Gear BDP-10A. The replacement on the other side was a BPD-10L-117 (according to my purchase record). The Exmark part number is 1-613042.

    I find replacement pumps online as BDP-10L-117P, at a wide range of prices ($450-$700).

    I have never rebuilt a pump, and am not confident enough in my mechanic skills to do so. I don't know what kind of seal might be involved with the bypass valve -- maybe this repair is relatively easy, without having to tear apart the rest of the pump.

    It is interesting there was no leak at the end of last season, but showed up after the machine sat idle over the Winter months (excepting having it out to run for awhile several times over the Winter). I never open/close the bypass valves during the runnning season, but use them every time to park the machine during the Winter. Apparently, exercising the valve a few times over the Winter was enough to create the leak, a leak from a weak seal.

    Thoughts? Try to repair? Replace with a 10L-117P? The expense of a new pump on a machine this old is questionable, but spending $5,000 for a new mower is also questionable. I expect to use this machine about 300 hours per season (used it many years as the only machine, but moved to part-time after buying a ZTR five years ago).
  2. tlc23

    tlc23 LawnSite Member
    Messages: 134

    It looks to be as simple as unscrewing it and replacing the o-ring. You can look up the repair manuals on hydro gear site.
    Posted via Mobile Device
  3. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    tlc is right Roger, After many heat cycles over the years the O-ring is likely brittle and cracked. Put a drain pan under the pump and remove the valve, You can likely match a O-ring up at your local hardware store, Otherwise a complete seal kit will be needed from Hydro-Gear......
  4. Roger

    Roger LawnSite Fanatic
    Messages: 5,943

    Thanks for the responses. I don't see a jam nut on the outside. Does the lever just screw out when it continues to be rotated? When opening the dump valve, I just open it a half turn or so. But, if I continue, will it come out, exposing the O-ring?

    I've not looked, but maybe there is a YouTube video on a rebuild. I've found other LS threads about rebuilds, but I never found anybody with a pictorial on the task. Maybe HydroGear has some pics/videos on their website.

    One other thing occured to me after I retired last night. I still have the other pump, the one I replaced in 2008. Maybe I could buy a gasket/seal kit, and work on it, while this one continues to run, albeit leaking a bit. Again, a YouTube would be critical to help my meager skills.
  5. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    Yep, That's all there is to it...... Not worth a rebuild/replacement just for a leaking O-ring.....
  6. Roger

    Roger LawnSite Fanatic
    Messages: 5,943

    Thanks for that info. I searched, and did find some YouTube videos. If I go further, these videos will be useful.

    Thanks again.
  7. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Messages: 2,249

    Roger, if you "retired" last night, you don't have a thing to worry about today!:laugh:
  8. Roger

    Roger LawnSite Fanatic
    Messages: 5,943

    Well, Dutch, "going to bed" seemed too final for the day's effort. "Retiring" is more of a transitional term to leave room for during-the-night revelations that may help solve the equipment problems for the day.

    If I would have "retired" on Dec 30, 2013, then yesterday's issue would have never been uncovered. But, what good is a day without some problem to solve?

    Anyway, back to our regularly scheduled programming ....

    I used the machine for about three hours of service today. Oil loss continued, but probably was less than a half-cup (estimate by the oil level in the reservoir).

    While working, I thought of the 2008 pump I had removed, now sitting on the shelf. When I got home, I pulled it off the shelf to see if the "just keep unscrewing the dump valve" advice given above. Yes, it came out. I see the O-ring, albeit a pretty small item.

    I had a class tonight, and the NAPA store was on the way. I stopped, gave them my valve piece. After some experimenting, I came away with an O-ring to try. The shoulder looks pretty big to stretch the ring across. The existing one looks to be square in cross section. But, it may have been round at one time earlier in the lifecyle.

    I shot some pics of the gear. The existing pump that is leaking has a label, BDP-10L-117P. The one on my shelf from 2008 is exactly the same. But, remember, these were on the original machine when I bought it long ago.

    The replacement pump has a new designation, a PL... number.

    Below are pics of the existing pump, leaking oil on the engine deck, the ID label, and a couple of pics of the dump valve pulled out of the shelf unit. The rest of the pics are on a DropBox folder. If somebody wishes to see more, PM and I will get you the link.

    I plan to work a full schedule tomorrow, but Friday has rain in the forecast. Since the present arrangement is workable, albeit leaking some oil, I will use the good weather to mow grass. If the grounds are damp, then I can work with the new O-rings on the dump valve. I will let you know what happened.

    Here is a YouTube video of a rebuild -- all gaskets and seals. The pump being rebuilt is a 10A, very similar to my unit. Is the procedure being used a good one? Is he giving reasonable advice on how to do this? If I choose to get a rebuild kit, I may wish to rebuild my shelf unit so that I have a spare.





    Last edited: Apr 9, 2014
  9. Roger

    Roger LawnSite Fanatic
    Messages: 5,943

    New O-ring installed this evening. A few passes around the driveway have promising results on stopping the oil leak. The machine will see more field work tomorrow, so I will have firm confirmation as to success.
  10. mowermankevin

    mowermankevin LawnSite Senior Member
    Messages: 270

    Roger, great pictures, excellent detail. If the O-ring replacement doesn't solve the problem,try this. With a blow gun clean off the pump, or better yet get a can of carb cleaner or gas and clean the pump. Take an Allen wrench and tighten the two screws that are on the top of the pump. It appears the oil is leaking out the top of the pump and not the by-pass. Start it up and you'll be able to see the oil leak on the clean, dry pump.

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