Thursday, July 27, 2017

Rebuild of a Hyd. Cylinder by the Mechanically Inept




Doesn’t matter how many into-the-sun glamor shots I take, nothing is going to change the fact that this cylinder on our tractor is dribbling hydraulic fluid all over the front tire at an ever increasing rate.

I’ve managed to go 63 years without having to rebuild a hydraulic cylinder, which, given my general mechanical ineptitude is a good thing, but life has caught up to me and now I have no choice.  At least no fiscally responsible choice since a new cylinder costs 7 times what a rebuild kit does. (Yep, I checked.)


So after going on-line and reading up on rebuilding hydraulic cylinders (I avoid the YouTube stuff because of our limited monthly data allowance out here in the sticks.) I stuffed one pocket full of rags, tucked a headlamp in the other, grabbed my ‘mechanics box’ (That's what Chanel Lock calls it and I figure they should know, though I've owned this set for over 30 years and it has done little to improve my mechanical aptitude. . . Maybe that's revenge for running over it with the tractor once.) and, rather cleverly I thought, a set of Chanel locks for grabbing the ends of the cylinder pins to pull them out, then set off down the hill to the tractor-barn.


That was about the end of things going smoothly.

First I needed an adjustable wrench (I played that smart by bringing two down with me) then I needed a magnetic pickup (I’ll get to that in a moment) then it was a screwdriver to pry the pins out far enough so I could get ahold of them with the Chanel locks, then it was – well, you get the idea.


All and all I made the trip from tractor-barn, past the well-house, and up to the main barn and back a good dozen times before I was finished (Finished with this stage, not finished with rebuilding the cylinder, not by a long shot!!)


First step was to remove the hydraulic hoses from the cylinder


I’m assuming keeping things clean is somehow important when messing with hydraulics, but since I don’t have any fancy caps laying around I improvised. Crude and maybe not all that effective, but it makes me feel better anyway. . .


Next step is to remove the bolts that hold the pins that hold the cylinder.


Here’s where I found I needed a screwdriver to pry on the far end of the pins to slide them out far enough to grab with the Chanel locks. One pin was easy to reach but the back-side of the other pin is butted up against some quarter-inch steel structure that keeps the front-end loader from crumbling to the ground, or worse, onto the operator, under load and that one was a bit more difficult to finagle out.


And remember that comment about keeping things clean?? At this point that went all to hell when I dropped one of the pins on the sandy floor of the tractor-barn. (easy to find but very gritty because of all the grease on it.)  Then I promptly turned around and dropped one of the nuts for the bolt that retains the pin!


That sand floor is not anywhere near a hard-packed surface, in fact it’s more like a fine beach just above the high-tide mark, and that nut buried itself in the sand faster than a flounder in mud, so the wages for that little screw-up was to tramp all the way up to the main barn and back to fetch my magnetic dumb-ass saver.

Hopefully I’m done dropping things, but – well – probably not. . .


Eventually I got the cylinder removed, went back up to the main barn to fetch a bucket to carry all the crap I had brought down on my various trips, and finally got the cylinder onto the workbench up in the main barn.

It was right about now that I noticed the two pins that hold the cylinder in place are different lengths and I didn’t make note of which was which. Oh well, I’ll figure that out when I get there, probably by discovering that the pin I just finished installing and bolting in place actually goes on the other end. . .


Here’s where I gloved up, grabbed some mineral oil, rags and pipe cleaners, and cleaned up the outside of the cylinder, the pins and the threads of the hose nipples and pin-retaining nuts and bolts.


It’s also where I discovered that I had no fixed and only one adjustable wrench in all my shop that would fit the gland, and it was totally the wrong kind of wrench for this job!

But what the hell! Work with what you have. That’s my impatient and penny-pinching philosophy!

So back down to the tractor-barn with the cleaned-up cylinder and my oh-so-wrong wrench to temporarily mount the cylinder end back in the tractor, (Fair warning!! Those mechanics out there that are sensitive and easily upset should skip the next photo!!!!)


so I could slap my big-honking pipe-wrench on the flats of the gland and twist it out of the cylinder far enough to turn by hand. (Hey, I gave you fair warning!)


Then it was cart everything back up to the main barn where I pulled the gland the rest of the way out and let the cylinder drain for a while. (If you noticed several photos back, my waste-oil pan is busy hanging out under the steering cylinder of the tractor which has a slow drip (One every 10 minutes or so) at one of the hose connections, hence the tiny little catch-pan here.)


With the cylinder (mostly) drained I could finally pull the shaft and piston out of it.

The thrill of victory was short lived once I saw all that gunk piled up there on the piston. I’m pretty sure that’s not right!!


But there’s no turning back now!

So I cleaned up the shaft/piston assembly and made the hike back down to the tractor-barn so I could remove the piston retention nut. Although I don’t have a 15/16’s socket, or open-end wrench for that matter, in my tool arsenal, at least this time I had a proper adjustable wrench that would fit.

I was a little leery of this step after reading about thread-lock, torches and impact wrenches to get this nut loose, but in actuality the nut only took about ¾ effort to break loose.

Whew!!


Back up at the main barn I finished removing the nut and pulled the piston off the shaft.

Clearly the O-ring has seen better days.


With the piston out of the way I was now able to slide the gland off the shaft.


And it immediately became clear why the dang thing was leaking.

You can see here that the second seal is crumbling away, big time,


leaving all sorts of debris hanging around.

I’m trying hard not to think about the fact that I’ve got three more identical cylinders on this tractor, all the same age, all with the same work and load history. Right now I’m just trying to get through this first cylinder with all of us in one piece and functioning!


Anyway – now that I have been able to verify the dimensions of my cylinder to confirm I was ordering the proper rebuild kit, it’s on its way and the saga will continue once the USPS does its thing.



4 comments:

  1. Replies
    1. Yep, soooo much fun it's criminal of me to keep it all to myself.

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  2. I can tell that you are just like me when it comes to anything mechanical. Show me a computer that doesn't work and I can usually get it going but just changing the oil can be a mind blowing event. Your post today reminded me of the time I replaced my two oil lines on the Class C I had purchased not 50 miles prior.

    Since you showed with photos and comments how "easy" this was, I bet you bought THREE rebuilding kits so you can do them all at once. Or did you bet that those other two will work longer than you live? If it were I, I would procrastinate and do them when I needed to.

    Penny pinching????? Two summers ago I need a new wheel for my mower, by buy all 4 to change at once when it's cheaper to buy just one cheap wheel.

    I'll remember this post when I need to repair a hydraulic cylinder ... a great write up.

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    Replies
    1. Oh no, I'm operating under the assumption that if I fix this one cylinder the rest will be fine forever, so I only ordered the one rebuild kit.

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