How To Change The Hydraulic Fluid In The Kubota Z421 Zero Turn Mower #178

[Music] hey everyone welcome back to williamson ridge outdoors today we are working on our kubota z421 so what we're going to be doing today is probably the most requested thing that i have had on my channel so far for me to do so what we're actually doing is going to be changing the hydraulic oil in our z421 and i'm going to take you through step by step and show you how to do this so follow along with us and let's get started so we've gone ahead and removed our filter cover it's actually held on by three 3 8 inch bolt and you just take those three out and you can see your filter is actually right here so we're just going to take that filter loose we're supposed to pull the bypasses also on the transmission before you take the filters loose so this the bypass is right down in here and you've got a little notch that thing lines up and you can pull it out past that and then hook it down below that so on the opposite side it's got the same little deal but there's nothing there for that thing to stay pulled out you can see it just slides back in so i'm not sure about that it says to release him on both sides but you can't keep it released unless you hold it so maybe if this poses a problem you know i can pull it out and put a pair of channel locks on it or something kind of lock it in there but anyways that's what it says to do so this filter was way too tight and i had to get a filter wrench and take this loose i had to work with that thing for a while to get it loose but we finally got it you just pull the filter loose and that's actually how you drain the hydraulic oil out of it is just by taking the filter off it's surprising how much dirt gets in that little filter cover that thing's plumb full of stuff so it's a good time to go ahead and just clean that out while you're at it [Music] so that's all there is to draining the hydraulic oil out of this so you just take the filters loose and that drains all the hydraulic oil out of it so according to the manual we're supposed to go ahead and put the filters back on and the filters that we're using are actually from kubota and they are the hydro gear commercial filters the same thing that came on it so this is the direct replacement i'll leave all the part numbers and stuff for these filters in the description below that way you'll have these filters if you've got a z421 so we pulled the filters on both sides of the transmission and drained it from both sides and before we do anything else we've got to put the filters back on so like i said we're using the factory replacement hydro gear commercial filters for this and really the next step is you just clean off your seat where your filter actually threads in or where your gasket makes contact and then you just take a little bit of oil and put on that filter and then you screw it back on and you're almost ready to start filling it up so one thing too on those filters those filters don't need to have a wrench to tighten those up like all you do is turn that filter to where that it starts to make contact with the gasket and then go three quarters of a turn and you pretty much do that by hand there's no need to use a filter wrench and torque these things down so the next thing after you tighten your filters down there's actually vent plugs that you have to take loose on this so whenever you're filling it up that it'll let the gear drive vent so our vent plug is this bolt right here that is an 11 16 bolt now the one on the other side is a little tricky to get to um you can get it with probably just a standard socket but a deep well there's not quite enough room over in here that'll give you an idea of what it looks like it's just it's actually the only silver bolt on here and like i said it's 11 16 so we're just going to pull that out to vent the gearbox so as you can see there's the vent hole and i'm gonna go up top now and fill it up with oil until it runs out of this hole so as you can see there the oil level came up to those plugs and started running out so then we put our plugs back in and one thing about it if you notice now it is completely dark outside you cannot get in a hurry trying to dump oil down through that even with those vents opened up it still doesn't flow really fast so it takes a lot of time to dump all the oil back down into that so let me show you the oil that we're using this is actually one of the biggest surprises for me is the type of oil that you use according to the manual it says 20 w50 motor oil i thought maybe that's a misprint maybe that's supposed to say hydro oil or hydraulic oil or something so i called the dealer and asked them about it they said absolutely you're supposed to use just a 20 w50 engine oil or motor oil so i picked up this fram and i even mentioned to the dealer i said well should i use synthetic oil in it he's like oh no not that's i mean you you could if you wanted but it's not necessary at all so i picked up the fram 20w50 conventional motor oil really because of the price i got this five quart jug for like 16.99 or something versus some of the synthetics and stuff that are well over 30 dollars so this is what i picked up so we're going to try it out and see how it does where you actually feel this at is through the tank at the top beside the seat and i apologize for the lighting because again it's just gotten dark and i didn't realize that it was going to take this long so actually the video and filling the tank back up is actually what took so long to do this doing it a second time i could probably do this in about 20 or 30 minutes but as you can see here when you fill this up you just fill it up through the oil tank itself so what we have left to do we still got to put our filter covers on but i didn't want to put those on there yet because i wanted to start up the machine and run it a little bit and make sure there's no leaks or anything like that so we filled the mower with that 20w50 motor oil and we fill it right through the little cap right here on this side but we filled it all the way up to the point where it was running out those vent holes and then we put the vents back in and then we continued to fill it until it took us to the full cold line on this little reservoir so now it's time to purge the system and what we've got to do on it is actually start the mower up run it at an idle and put the gears or put the drive in neutral so the left side over here we actually pulled out and it actually has a little wing where you pull it out and it locks into place the right side you actually have to pull it out and hold it so what i did since i'm doing this by myself is pulled it out and put a set of vice grips on it and locked it into place so let's fire this thing up and get it purged so we're going to take the levers moving forward and back five or six times [Music] so now i'm going to unlock the hydraulics or re-engage them and then do it again five or six more times i'm gonna go ahead and do it twice just thinking that that may the first time get all the air out of the system so i went ahead and disengaged the hydraulic drive so now i'm gonna do the same thing again and work the six five or six times now i'm going to re-engage the drive and do it one more time and then we're going to set it down on the ground and try it out [Applause] that actually feels really really good in fact i think it does actually feel a little bit better than it did before maybe the system maybe it had a little bit of air in it before or it's just from the dirty oil that was in it so all i've got left to do now is put those filter covers back on and i need to move the mower to a perfectly flat area just to get a perfect check on the the fill level on it but you can see here on the tank itself it's got a full cold mark and it's all the way here at the bottom and the cap says do not top off which means don't fill this tank up and then expect it to go down that's where it should pretty much stay it really does not take very long to do this it took me a lot longer because of videoing it for one two being the first time that i did it three the longest part of it is actually filling it back up with oil so if you do this on a real good warm day like if i would have done it today i would have set my oil bottles out in the sun for a few hours before i started to do this so that that oil would actually kind of flow a little bit better but last night whenever i was doing it actually was only about 50 degrees or so that stuff's pretty thick anyways it's kind of like a honey consistency and then whenever it's cold it makes it that much harder for it to go down those little tubes so it took me quite a while to get all that oil in there it actually did not hold as much as i thought it would it's only about four or four and a half quarts at the most take your time with it make sure that you get the correct amount in it don't overfill it so that's going to wrap it up for a hydrostatic oil change on our kubota z421 like i say it's not a hard job at all it just took a little bit of time refilling it with that 20w50 oil but if you enjoyed today's video and you found it helpful make sure to hit that thumbs up button if i've left something out you have any questions or anything make sure to leave them in the comments below subscribe to the channel and follow along with all the projects we've got going on around the farm and thanks for watching

Channel: Williamson Ridge Outdoors

Views: 3,048

Rating: 5 out of 5

Keywords: how to change the hydraulic fluid in a kubota z421 zero turn mower, how to change the hydraulic fluid in a zero turn mower, zero turn hydro oil change, kubota hydro oil change, z421 hydro gear oil change, kubota z421 hydraulic fluid change, hydro gear oil change, hydro gear fluid change, hydrogear fluid change, hydrogear oil change, kubota z421 oil change, kubota z421, kubota z421 zero turn, kubota zero turn, hydro gear purge procedure, hydro gear 3600 fluid change

Id: 6xzBsRuy0QA

Length: 11min 56sec (716 seconds)

Published: Wed May 26 2021