John Deere 400 Hydraulic Motor Rebuild | Sundstrand Series 15 Model 90 Inline Hydraulic Motor

[@EvilRace]

Best video about hydraulic motors repair. You motivated me to repair my Thomas T133 pump myself. Did you use a special silicone? When I disassembled mine, I saw previous owner used silicone for the o-rings holes instead the o-rings themselves. Do you think it can work? On the other hand, my other bigger deal is finding the rotating group. Thomas asked me for $1400 but I found kits in Aliexpress for $400 which look reliable. However Aliexpress sellers only gave me the reference of 78462 after providing dimensions, but other supplier gave me 72400 and 78363, do you know where I can get my exact reference? In the parts manual of Thomas I don't see any of those numbers. Thank you!

[@WorkshopRebuild]

Thank you for your feedback, I appreciate it!! That's a great idea, there's nothing really hard about an hydraulic motor, you just need to be very clean when reassembling the whole unit. I did not use special silicone, it's a RTV sealant, which will work perfectly fine. You can pick this up at your local hardware store. I personally would not rely on silicone where O-rings are needed! The previous owner must have added silicone to the surface of the hydraulic motor blocks, so when they merge the silicone acts as a sealant. I would use an oring, as the manufacturer does. The Oring does a better job, since it needs to keep oil flow to one of the external passages & within a high-pressure area for the pump. Try and measure up the diameter and figure out the CS (cross-section) for your O-ring. On your barrel-assembly, you really want to make sure the assembly is exactly the same to the original. I wouldn't go based off OEM-Part numbers unless you're purchasing directly from the manufacturer. If you're looking elsewhere, you should find the exact sizes. Measure the barrel-diameter, pistons sizes, piston count and so on. If everything adds up, you can probably find a match to an aftermarket barrel assembly. I hope that helps. Best regards

[@MichaelTJD60]

Very cool to see the inline version of the popular U-pump used on a lot of other garden tractors. It's also neat that Sauer-Danfoss still manufactures the model 90 pump in all of its configurations to this day - it's a 50+ year old design, but still works very well and has a ton of applications today.

[@WorkshopRebuild]

Amazing information once again Michael, thank you! There are so many application for this hydraulic motor in all the variations and I bet they just had one of the best designs back in the day, and if there is still demand, why not keep on using it! This hour meter on this hydraulic motor was around 1000hours, so I hope I can get at least double of the life-span after this rebuild! I noticed the Inline hydraulic motor has fewer parts and therefore it may be more reliable than the U-Pump, but in all, they are both very sleek units! Best regards

[@4cornerssmallengineandfabr535]

I love how easy you make it look, and thank you for the detailed list.

[@WorkshopRebuild]

Everything is easy once there is understanding. The clean-up is probably the most time-consuming part of this all. The disassembly & assembly should take about 30-45 mins if all the parts internally are in good condition. I hope it helps you out! Best regards

[@daneprep5702]

Dude, you are the man!! Just subscribed and thanks a million.

[@WorkshopRebuild]

You are more than welcome and thank you!! I hope it works out for you and I really appreciate your support! Best regards Andreas

[@markchidester6239]

The hardened pin you have in the description is the wrong size. You have a 1/16" by 1". It is 1/8" and from what i can measure from my broken pin, it is 1.025 long. JD # is M49524. I do wish you would have shown how you removed the bearings from the shafts and the seals. The front seal i had to press the needle bearing that you didn't mention out which in turn pushed the front seal out. Other than that, nice video. Whatever anyone does, don't go to JD for parts. That 85x3mm o-ring and front seal cost me $45.

[@chadhaulbrook9339]

I'm loving your videos on the JD 400. I'm buying one to restore and this is so helpful. I go and pick mine up next weekend. Where are you located?

[@WorkshopRebuild]

Thank you very much Chad! It's great to hear another JD400 will be saved and restored. These machines are awesome in so many ways and they are super handy to have around a bigger property. I hope you enjoy the restoration process and hopefully you learn a lot along the way too. I'm located in central Alberta. Regards Andreas

[@gabrielparedes5991]

hello there I have a sundstrand inline hydro model HT 901122 can you tell me where can buy replacement kit for that transmission is there any place around VA USA

[@WorkshopRebuild]

Hello Gabriel, it should be the same assembly as in this video, but with slight variations according to your machine. I did not find any information on this number, but if you can tell me what it came out of, I might be able to figure out where you can purchase a kit. Messicks sells some kits for Sundstrand, but you would have to verify that with them. Best regards

[@gabrielparedes5991]

@@WorkshopRebuild 1969 Massey ferguson 16 lawn tractor it has 16 HP kohler and Hydro transmission that number is from parts manual book i will apreciate you help thanks reply please

[@WorkshopRebuild]

I just searched on eBay and your setup is exactly the same as the one in this video! The only difference is that you have a spline on the input shaft for your driveshaft. Either way, I did not find any rebuild kits for this assembly whatsoever. If you reach out to Messicks (farm equipment) they should be able to help you. This is a Sundstrand Series 15 Model 90 - Inline Hydraulic Motor/Pump. You Serial number is HT90-1122 and the 1122 refers to your specific setup for your Massey Ferguson 16. If you reach out to them by E-Mail they will have the correct numbers and they can possibly get you a kit. If you want you can call them too. I hope this helps. Best regards

[@gabrielparedes5991]

@@WorkshopRebuild Thanks for all you help good information thanks again

[@WorkshopRebuild]

@@gabrielparedes5991 You're more than welcome!

[@mhoch1736]

What could be a reason for only having forward and reverse? No power steering, no lift?

[@WorkshopRebuild]

Hi, if forward and reverse are working fine, then your hydraulic pump in conjunction with your motor are in working order. If you do not have power steering nor lift capabilities, that could mean your charge pump/ auxiliary pump is not working propperly. If you want more info about your auxiliary pump, check out the section in this video from 40:56 onwards. If you think that's not the problem, then you might have issues with your valve block. I made a video about that too right here: kzbin.info/www/bejne/rH2xgGmlqtJ_rJY If you have any updates or further questions, just let me know with a comment! I hope this helps!! Regards Andreas

[@mhoch1736]

@@WorkshopRebuild thank you

[@mhoch1736]

If removing the inlet line at the valve block, and start it, It should spray out correct? If not, that should isolate it back to the pump?

[@mhoch1736]

Also, could you help clear something up? How many pumps are in the sundstrand?

[@WorkshopRebuild]

@@mhoch1736 That would be an easy test and you are correct. If you remove the inlet line to the hydraulic valve block and start up the engine, you should have fluid pumping out. If you have little to no flow, then your charge pump may have an issue.

[@Johndeere8137]

Very nice video, I have a 400 that is loosing power slowly and reverse is very slow. Would putting new gaskets and seals fix that or is there a way to get new pistons?

[@WorkshopRebuild]

Hello Jon and thank you! It's hard to say what exactly is causing this issue, but it could be the pump of this assembly or the motor. Many JD enthusiasts on Facebook try to get away with a filter & oil-change which could work, but if you have excess wear inside then it will not allow enough pressure to build up. If your seals and gaskets and leaking bad, I would suggest to replace them. If your tractor is getting slower by the day and your rear-end is leaking even worse, then this might just be the issue. I'm actually not sure if these piston assemblies + valves are readily available! If you have some time and patience maybe yours can be rebuilt with just some gaskets (which are available). You can share an update with me if you want to and I can help you from there. Best regards -Andreas

[@Johndeere8137]

@@WorkshopRebuild thanks Andreas I was thinking of just getting a new hydrostatic motor in better condition.

[@Johndeere8137]

Also what is the best way to get rid of the paint on the hood and fender, for repainting?

[@WorkshopRebuild]

@@Johndeere8137 That is not a bad idea! I hope it works out for you, so you can have a smooth operating JD 400.

[@WorkshopRebuild]

@@Johndeere8137 The hood is fiberglass and you can sand through that paint fairly easy. The fender on the other hand is VERY THICK paint and I would suggest to get this blasted (if possible). I removed all my paint with a DA sander & wire wheel, but this was very time-consuming. I will share a proper paint-prep video in the future, but I hope my advice helps you currently. Best regards

[@TheVinnivee]

where do you service the hyd fluid?

[@WorkshopRebuild]

You will want to look at the rear-end (differential). There is a drain plug on the bottom that can be removed and all you fluid will come out of there. Check this video out at minute 02:00 for more information: kzbin.info/www/bejne/ppbLh4iXmqmBpJY All the fluid is housed within this area and hopefully you'll have a better understanding of everything.

[@tdogj2084]

Fram oil filters are garbage it used to be wix was garbage and fram was good quality but not any more!

[@WorkshopRebuild]

Thank you for sharing your perspective. It's important to consider various opinions when evaluating products. Different users may have different experiences with different brands. If you have had negative experiences with Fram oil filters, you might want to explore alternative options that better suit your needs and preferences. Ultimately, the choice of oil filter brand often comes down to personal preference and individual experiences.

[@tdogj2084]

@@WorkshopRebuild The premium line of fram oil filters are just as good as the wix brand but they cost more then the wix brand !