Is the bore too scuffed up? | Hydraulic Piston/Cylinder Removal and Inspection | David Brown 990 #11 

Thanks Barry! I'm thinking I'll do like you suggest and lightly stone it. At the very least a bit of scotchbrite. My oil feed pipe comes into a block inside the axle casting that feeds up to the bypass filter as well as goes out the hole to the cover. It stays put on mine and doesn't seem to come out.

Now to learn how to hone a cylinder. Never done that before! Thanks for watching!

@@path.of.discovery ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-f7JuMGsyDAg.html it's in an engine block, but same process :)

It definitely had some trash in it that's for sure. Milky oil, years of sitting (covered, but still sitting) and the backer ring had fully disintegrated. Original backer is of leather material and I'm thinking that may have been what scored up the piston? As the leather backer came off it ground up and maybe caused all the damage. Thank you for a very detailed comment on some things to do. I'm thinking I'll hone the bore lightly and polish the piston just like you recommend. Not going to replace the piston. Will replace all the o-rings and backer though. I'll check out that channel, thanks for the recommendation! I'm definitely not a machinist, but here in the last 10 years or so I've been watching tons of content like that. AvE, Abom79, ThisOldTony, NYCnc have all taught me so much in that area. I'm a computer/programming nerd by trade and hobby, and just recently got into this mechanic and restoration stuff myself. Learning a ton, and figured I'd video it to learn editing/sound and maybe help someone along the way. Thanks for watching!

@@path.of.discovery Leather with trash on it would surely do it... I'm working with a 20 ton hydraulic Harbor Freight jack right now that the pump for it has failed. Small 3/8ths ish? piston rod, goes to the pump handle on one end that you jack it up with and has an o-ring and plastic backer on the other end, about the size of your small pinkie fingernail in diameter. The "barrel" is about a 13/16ths wrench hex, threaded on the end to screw into the base. I'm sure you know the part. Well mine quit jacking at about half piston stroke. Checked the fluid (why should it have leaked out in the first place????), and it was fine. Jack sits on my press outside all the time, so..... I took it apart, and there was some minor scoring on the inside the barrel, the o-ring felt like it had some very small nicks in it (again, outside in the weather and tops not sealed), and the piston didn't slide inside the barrel smoothly. So I took a reamer I had that was close in diameter to the barrel, wrapped some 1000 grit wet/dry around it and went at it with it in my drill. No lateral pressure as best I could, just front to back with drill flat getting it. Put the piston into the lathe, hit the hole for the handle assy with a file then some more of the wet/dry and polished it all up. I still need to go to the local hydro store and get a good o-ring, but NOW the piston slides in and out even with the old o-ring VERY smoothly with no catches anywhere. I've rebuilt several engines in my life, and I always run a hone and try to make things as clean and shiny as I can, especially where any kind of pressure is concerned. I've also rebuilt a couple of hydro cylinders recently and the bores were good, and I just light polished the piston part before putting it all together with new parts. Remember it's not the walls of the piston that make the pressure work, just the o-ring, but you def wanna make sure there's nothing to catch the walls of the barrel as it slides. Lucia's workshop on here is also another great home shop machinist channel too, and she's easy on the eyes :D Hopefully you've got a true Hydraulic repair shop around you that can help you and advise you on parts, I know how guessing and hoping you order the right ones can be nerve wracking!!!! Me, I've got a Southbend Heavy 10L about 50+ years old sitting in a school bus I've acquired and turned into a machine shop for me. I'm one of those folks who loves to make things, weld things, break things..... hahaha I'm no expert by any means, just a broke redneck at the moment with a yard full of pickups, semi's, vans, motorcycles and trailers just cause I can. Made good money too back in the day as the Network Admin for a multi-million dollar furniture company too /wink .... Got like 4 or 5 servers laying around here somewhere I really should do something with..... I suggest acquiring something like a Southbend 9 or 10 lathe, at least a small milling machine or a Grizzly mill (they're GREAT from what I've seen and read), and you'll find life gets a lot easier, especially when you're taking the turn table rotator apart on a Gallon 503 and the upside down castle nut SPLITS trying to take the drive gear out (taper fit like a ball joint, it's the part that actually rotates the blade on the grader) and you have to recut the threads on this 1 1/8th inch shaft, then have to MAKE a nut for it cause no one in town has one :D hehehehehehe Ok enough now.... Will be looking for the next vid on this project.... it should prove interesting for sure!!!!

@@path.of.discovery ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Aa2csAP8M6I.html is CEE's vid at the point he puts gas into the cylinder to check for a bad weld joint that was preexisting Don't watch too many of his vids, you'll get addicted .... like me...... ROFL

@@shuntawolf Thanks for the info and other recommendations to channels, I've got a bunch more videos to watch in my future! I REALLY need to get a Lathe and Mill. Thanks for the recommendations on the lathe and mill, I'll look into those. I'm space constrained at the moment though (subdivision life) so it'll be a couple more years until I get anything. I keep watching local auction sites for deals though. There are several machine shops and hydraulic repair shops around that I've found lately, so I've got some options locally to have stuff made and get advice.

@@shanebush9226 The SB 9 & 10's are essentially table top lathes. I think my 10 is like 3.5ft? About the size of a desk width wise, and about half as deep. Mine sits on a cabinet made for it and has wheels!!! hahaha. Can hide in the corner of a garage real easy. I have a 3ph motor on it, and a 1ph-3ph converter from Amazon which works WONDERS for controlling the speed. The smaller Grizzly mill I saw had about the footprint the size of a fridge, with the table sticking out a foot or two beyond what a fridge would take up and about as tall. I got my SB for $600, but it was in pieces as the guy before whom I got it from began restoring it, and whom I got it from never did anything with it. Typically I've seen them around $1,000. Definitely get a 4 jaw chuck if ya can though. I'll say this then maybe shut up (doubt it haha), I've had several cases where I needed something, and having the lathe saved me time and money where I could either drive round trip an hour to go spend money on a piece of material, when I made it from scrap laying around in a matter of minutes. Nuts, modified bolts, shafts... all kinds of little stuff. With that old tractor, you'll definitely use it more than you think :) Have a great week bud!!!! I'll be glad to try and answer any questions ya might have or at least point ya in the right direction for answers, my email is my username a the G mail service :)

I've got a hone with 240 and 320 grit stones on order. Should be here end of weekish. Thanks for the tips!

I definitely agree with you on the gaskets. The update video to this one goes over honing the cylinder a bit and polishing it up. Turned out really smooth and nice. Fresh o-ring and backer and this thing will be a beast again. You're right about these tractors being super strong. My grandfather treated this one like a bulldozer. Super strong lift when it's sealed up right.

@@path.of.discovery Many thanks for answering. You have no idea how mu$$$$ch this whole thing has cost from the very beginning in 2012. But I saw those tractors in action when I was a boy. The overall looking, the sound they're making... especially the 880 and 990 ! But if I had to do it all over again, I would buy a 885 with 12 speeds synchro instead. My 880 was in a bad shape. No regrets here.

Hi!