hydro gear 2800 Oil Change Problem

smithboy

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Hi folks,
This is my first post. I have a big dog alpha MP, which is a re-branded hustler 54". I changed my oil and filters today in the two hydro gear 2800 units. I missed the 75-hour mark by a bit. I am at 89 hours currently. I followed the instructions for filling and purging. I used Castrol GTX 20W50 (conventional oil). When I drained the oil, it was cloudy, so it probably did need changing. However, after purging, I cut my grass for about 15-20 minutes and BOTH hydro gears went out suddenly and simultaneously. It was as if a switch had been flipped turning off both hydro gears at the exact same time. I was actually done mowing and returning to its parking place and didn't make it back. I tried doing the purge a second time, but never got power back to the wheels. As an information item, I didn't prefill the filters as it didn't say to do that in my service manual. I just filled until oil ran out both holes at the top of the two units. I used Stens filters, as these were the ones available at my local mower shop. I wondered if I need to open the vent holes again and see if more oil goes in. Currently, there is oil in the overflow tank (only one overflow tank on this mower). I also thought it might be overheated. The transmissions were pretty warm to the touch, so I let is sit for an hour or two and tried again...nothing.

Any ideas?
 

bertsmobile1

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Some hydros can be a right royal PIA to bleed, particularly the ones that use a common overflow as when one side overflows, it stops the other side from venting.
I have needed to hook up the sump oil pump to the overflow on more than one mower to pull a vacuum on the overflow tube to suck the air out while purging the box.
And some have needed to be done may times before they some fully good.
On most hydros it is very important to run the engine as slow as possible when purging the air our of them to prevent the oil frothing in the box.
So it is back to step one for you.
And yes check the oil level if you can on both of them.
 

ILENGINE

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Both unit failing at the same time sounds more like the drive belt came off or broke.
 

cpurvis

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Both unit failing at the same time sounds more like the drive belt came off or broke.
Or the pump itself quit pumping. That's the component of the system that's common to both hydros. If it goes, they go.
 

ILENGINE

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Or the pump itself quit pumping. That's the component of the system that's common to both hydros. If it goes, they go.

Unless my memory is failing the 2800 series is a left and right individual self contained hydro drive units. So there would be two pumps/ two motors, two separate drives with nothing common between them other than the drive belt and in this case the expansion tank.
 

L454S

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How much oil did you end up putting back in total? Mine took over 4 its with the vent plugs removed, then top off a little after purge and run in.
 

cpurvis

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Unless my memory is failing the 2800 series is a left and right individual self contained hydro drive units. So there would be two pumps/ two motors, two separate drives with nothing common between them other than the drive belt and in this case the expansion tank.
Good point. I was assuming there was only one pump.
 

smithboy

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Looks like Ilengine is right...When I wrote my initial post, it was too dark to see much, so I decided to put it out of my mind until today. The idea that I made a mistake that cost two of these pumps was really bothering me. This morning, with a fresh cup of coffee, I lifted the rear of the mower to start the purge process over and saw immediately that the drive belt had wrapped around the left side pump pulley and fan (miraculously without breaking anything else). I have already ordered a new belt, as this one was toast. It had a pretty big cut from coming off the pulley. However, I also noticed the thing that I think caused the belt to come off. The cross member had a broken bolt on the right side. The front mounting bolt for the right hydro gear was also broken...That's TWO broken mounting bolts that I didn't notice when under the mower the first time. This actually caused the right side wheel to be cambered enough to result in the belt to run off the right side pump pulley (at least that's what I think). I replaced the bolt on the cross member, but the mounting bolt is giving me a hard time because the hole isn't exactly aligned. I made a trip to Tractor Supply to pick up some replacement bolts for the other side of the cross member and for pump mounting bolts. I am hoping that in replacing a couple of other bolts, I may be able to re-align the hole for the broken bolt. I am also hoping this is just a huge coincidence that the one thing that would kill power from both hydro gear pumps broke RIGHT AFTER I DID THE SERVICE. My belt is supposed to arrive next week, so I will post my results...Thanks for the help, and I look forward to continued participation in the forum.

As an aside, I added a little more than 4 quarts of oil to the two units. I let one start leaking an plugged it. Then filled until the other leaked, then plugged it. Did the purge as directed twice with wheels up. Also, everything I saw suggested that the purge ports were 11/16th plugs, but mine were allen wrench.
 

bertsmobile1

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Check with your dealer there is an upgrade / recall on some Hustlers for that exact reason.
You might be covered for the new brace.
If you troll through the Hustler section you will find a lot of traffic about this problem , including the fix and what models the fix is free on.
The new belt will not last long so get a couple of cheapies till that brace is fixed.
 

smithboy

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Unfortunately for me, I bought the mower used and was told early in the process that the warranty for my mower didn't extend to the second owner. I did, however, find one of the threads you mentioned and it was really informative. In looking over the newer design, Hustler did increase the bulk and rigidity of the new unit. However, I think my overarching problem was due to corrosion and friction on the bolts. The main features of the new design (outside of more metal) are that it reduces the chance of corrosion by eliminating the V-channel and it reinforces the lower mount bolt receivers with thick-walled tubes. However, in my non-engineer's eyes, it looks like I can achieve similar results (or at least better than factory results) by modifying the original unit with a bit of welding and some hardened stainless bolts. I can weld in bolt support. It also appears that by carrying the cross member to the outboard side of the transmission mounts, sandwiching the bottom of the transmission would be better. Stainless bolts aren't as strong as the hardened bolts, but stainless is better in friction and corrosion situations; however, I do intend to call about the upgraded part and ask if I qualify. I am also open to suggestions on modifications to the original unit. These are just my first thoughts.
 
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