Hydro gear pump and system fixed!

Discussion in 'Mechanic and Repair' started by rwbsod, Mar 23, 2013.

  1. rwbsod

    rwbsod LawnSite Member
    Messages: 14

    Thanks to LawnSite and You tube I solved the issues on my hydro-gear drive system

    I bet a lot of people fix their problems by reading forums but we don't get to see how it went and how they solved their problems. I have done the same thing. So this time I want to post how my problems got solved. I hope my experience helps some one out there.

    Machine- I bought a used Exmark Turf Tracer 48" WB. It worked fine at first butt...

    Symptoms- Over time oil started getting everywhere! It was on the outside of the pumps, On top of the frame, And underneath was plastered with gooey with oily grassy nastiness. Eventually the left pump (and the leakiest) would not power the left wheel in either direction when it was cold. It would kind of groan and surge as I worked the controls back and forth going in circles While my crew would look at me and ask each other, "what is wrong with him"!? The oil tank would overflow some times and the Oil was really bubbly. Eventually it would start working after it warmed up

    Diagnosis- I asked a local shop if the pumps could re sealed or rebuilt. They said if I did, it still wouldn't work and to just "runn'em till they fail" and buy a new pumps for $600 a piece! My friend has a lawn mowing business and he told me the same thing! It just bugged me, I couldn't believe they couldn't be repaired. so I started to search and found a couple you tube vids on how to rebuild them. Turns out they can be rebuilt for less than $200! Then Google lead me to posts on this site about other people fixing them. So I tore the pump apart that was giving my trouble and it actually looked really good inside. The valve plate showed some wear but but not bad at all. I couldn't see any obvious signs on what was causing the problems. So I continued to search threads here till I came across a thread that revealed the common Exmark problems with the brass crimps not being very tight and sucking air on some of the smaller hydraulic lines. Sure enough, mine were loose and sloppy! That explained the severe bubbles in my tank and even overflowing, 'till the bad connections warmed and sealed up. Turns out the pumps weren't even bad!! my oil didn't have glitter or shavings so that made sense.

    Solution- I removed the brass crimps on the two tees and installed hose clamps. The right pump had actually been replaced with a newer pump before so it was in fine shape. But I threw a re seal kit in it too while I was in there. The left pump was definitely leaking bad so Installed a new seal kit and a new valve plate while it was apart. I filled the pumps with oil as i put them back together, (Making sure indentation marks on charge pump caps were in the rite direction) filled the new oil filter, installed the pumps, filled the tank with oil, Jacked the back of the mower up, started it up, put it at 3/4 throttle and let it run in full forward. In about 10 minutes the air was out of the system and the wheels were running at full power and it drives great now! No air bubbles in oil and no leaks!

    Sorry this was long. Hope my story helps you get back on your sulky in no time!
  2. ReddensLawnCare

    ReddensLawnCare LawnSite Bronze Member
    Messages: 1,651

    I'm having the same problem. Good to know.
    Posted via Mobile Device
  3. Greg78

    Greg78 LawnSite Silver Member
    Messages: 2,010

    Glad you got it fixed. I hate the "run it till it breaks" mentality. Same thing the local dealer told me when my pump was going out, along with "shavings in the reservoir is just natural wear". I've learned to do most everything myself with the help of the regulars on this forum.

    Proud to say I haven't stepped foot into the dealership that gave me that advice for over 6 months now.
  4. ReddensLawnCare

    ReddensLawnCare LawnSite Bronze Member
    Messages: 1,651

    Can you send me the link for the rebuild kit
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  5. rwbsod

    rwbsod LawnSite Member
    Messages: 14

    Yea I read your thread about that. It's truly amazing. I do all my own work on my vehicles, farm equipment, ATV's, Motorcycles, Lawn maintenance equipment, everything. I've been burned by "certified" mechanics too

    It would be horror if I ran that pump "till it failed" and spread metal shards throughout the entire system! it would take so long to clean out every part in the whole system! not to mention the damage debris could cause to expensive drive motors. Fix it before that happens! it's called preventative maintenance.

    Come to think of it, has any one rebuilt a drive motor? are they rebuild able too?
  6. rwbsod

    rwbsod LawnSite Member
    Messages: 14

    I got my parts at http://www.jackssmallengines.com/. You can get the "over haul seal kits" and any other internal parts there too. They were reasonably priced and fast shipping
  7. BigFish

    BigFish LawnSite Platinum Member
    Messages: 4,192

    Yeah, lots of times. Posted pics here. not difficult, just keep it clean.
  8. rwbsod

    rwbsod LawnSite Member
    Messages: 14

    Cool. Mine don't leak but have a little play. is that OK?
  9. jkilov

    jkilov LawnSite Bronze Member
    from MS
    Messages: 1,415

    Some designs (with charge pumps) are less vulnerable than others, but running a pump with air in system will eventually ruin it due to cavitation.

    Glad to see you inspected the issue before "running it till it breaks".

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