Thursday, August 3, 2017

The Mechanically Inept Calls This Project Done!



Of course the title of this post could imply either success, or unconditional surrender.

At this moment it could go either way!


The final stage of this project should have, but didn't quite get started one morning as we were getting ready to make a run into town. Which town depends on several things, what supplies we need to buy, where we want to eat out, and whether we need to hit the post office. (Because the post office refuses to deliver to our address we have to use a PO Box.)

 I checked the tracking number that Circle G Tractor had given me for the parts I ordered and discovered that they had been delivered to the post office at 0732 that morning, so now we knew which direction we were going. (That particular town is 15 miles to the southeast.)

It was after 10 by the time we hit the post office but the parts were not in our box, (They guarantee your day’s mail will be in the box by 0900. No, seriously, it says so right there on that poster hung on the wall!) nor was there a yellow pickup slip waiting for me, only a couple of catalogs and other scrap crap. I went to the counter anyway, pulling up their own web-site site on my phone showing my package had been delivered as I waited in line so they couldn't feed me any lies when I finally got to the head of the line.

Remember a couple posts ago I mentioned that though storms may not stop them, our particular post office is highly allergic to anything that smells like customer service? Well the excuse today was that they were too busy to deal with packages. I pointed out that it wasn’t a package but rather a Priority Mail envelope that I had paid extra for so as to ensure timely delivery (OK, so it was the least expensive option offered by Circle G Tractor but what the hell, I paid for it!) and it was probably sitting right there in a bin just on the other side of the wall and I’d wait while they went and got it. Well the thought of doing something so sensible and customer friendly had about the same effect as turning on the lights in a roach infested kitchen. They scurried frantically for the dark corners and I walked out without my parts.

It was several days later before The Wife made a special trip to go collect my rightful parts held hostage so un-rightfully, driving the shipping costs up by 1 gallon worth of fuel.

But anyway, I now had my parts. They came with no instructions, drawing, nothing like that, but they were in a nice, neat, professional looking little sealed bag so I did, presumably, have everything needed to rebuild my cylinder except for the knowledge.


So the next morning I bravely collected all the bits and pieces I thought I was going to need to finish this project off and laid them out neatly on a fresh chunk of clean craft-paper.


Then I opened up my hard-won little package and laid all the bits out next to where I thought they should go. Fortunately I had resisted the temptation to get over-exuberant a few days ago when disassembling the cylinder and all the components still had their bits and pieces in place so I could make careful visual checks on where everything went.


Having had one other experience with seals before, on one of the 4-wheel drive tractor’s  front wheel drive-steer units, I already knew that getting the old seals out and the new ones in was not going to be a walk in the park, so I chose to start with the most difficult component first, the gland.

Now some would argue that I should start with something easy in order to get a little experience. But I would argue that if I’m going to fail it will probably be on the hardest part and then I would just be wasting the effort I put into the easy parts if I did them first.

Anyway, after checking things out one last time to make sure I knew where and, which way, each of the two new gland-seals went


I used a fresh #11 blade to carefully cut through the old seals and remove them.

Then I cleaned up the inside bore of the gland, including the seal-seats, while the two new seals simmered in a pot on a camp stove (Which is actually The Van’s main stove.)

Just before I pulled the first seal out of the pot, presumably soft and pliable now, (More like less hard and not quite so stiff) I wiped the inside of the gland’s bore and seats with fresh hydraulic oil.


Then using a combination of slightly burned fingers and carefully sanded and cleaned wooden push-sticks, I worked the seals into place.

Now taken at face value that sentence makes it sound pretty straightforward. Well it wasn’t. . . I think that first seal, the one furthest away in the photo, went back into the simmering water three or four times before I finally figured out the right combination of finger and stick moves to get it to pop into its seat, which has to be done without damaging the seal or letting it flip around the wrong way.


As far as the gland goes, the hard part was done!!  All I had to do now was toss the outer O-ring and its hard-plastic backer into the pot for a few minutes while I checked a previously taken photo to verify which order they went on,


wipe the area down with more hydraulic oil, then slip them into place like fitting a too-small condom onto a - well - you know. . .

In case any readers are starting to get the impression I know what I’m doing, when I took this photo I deliberately turned one of the gland’s ‘flats’ towards the camera so the consequences of my less-than-competent use of a grossly-wrong-for-the-job pipe-wrench to remove the gland from the cylinder would be evident.

I’m sure to real mechanics this is blasphemy, or at least just plain wrong, but being a fake mechanic it seems pretty normal to me. . .


With the gland finished and set aside it was time to tackle the piston.

Actually the piston’s original seals, shown here, don’t look bad at all and there was some temptation to just leave them alone, but since I’d already come this far. . .

Again, the old seals were cut through with a #11 blade, being careful not to mar the piston itself. Once the old seals were off I cleaned up the piston and seal-seats, wiped everything down with hydraulic oil,


and worked the well simmered new seals into place, being doubly careful to make sure they were oriented the right way (If you look close you can see that each one has one edge that protrudes more than the other. This edge is supposed to face the nearest piston face so hydraulic pressure forces it deeper into its seat while pushing the protruding lip tight against the bore of the cylinder.)

Again, it took me several tries to figure out the secret of getting these way-too-small seals over the way-to-big piston and into the seat without damage. It took many trips back into the simmering pot and I definitely could have used three burned thumbs instead of just the two I had available, but eventually I managed.

By contrast the O-ring that seals between the piston and the shaft is hardly worth mentioning, except to say that after sliding the gland onto the cleaned and oiled shaft, making sure it faced the right way, and just as I was getting ready to slide the piston back on the shaft I figured out it would be less wear and tear getting that new O-ring over the threads on the end of the shaft if I slipped it on first by itself then put the piston on.


Now it was time for another of those infamous trips down to the tractor-barn where I temporarily pinned the end of the shaft in place to hold it while I tighten the new nyloc-nut down to keep the piston in place on the shaft. (Just imagine the disaster if that were to come loose!! On second though, I'd rather not. . .)

It’s pretty dirty down there in the tractor-barn so I was careful to keep the rebuilt assembly clean and as soon as the nut was tight I brought the shaft assembly back up to the clean(er) main barn.


Where I swabbed the cylinder bore down with hydraulic oil using my rag-zip-tied-on-a-stick trick, then, after one final wipe-down of the shaft assembly, slid it into the bore, careful to ease the piston seals and gland O-ring over the bore’s threads without damaging them, the seals I mean, the threads are pretty tough.

I tightened the gland as far as I could by hand then it was back down to the tractor-barn with the assembled cylinder, and yes, my big honking pipe-wrench, where I once again pinned the cylinder in place temporarily so I could seat the gland into place.


Now I was ready to pin the cylinder back where it belonged for good, so I greased up the pins and slots before bolting them in place then, for good luck, and perhaps to delay the inevitable,I hit the zerk-fitings with a couple of shots from the grease gun.


All that was left to do now was to screw the hydraulic hoses back on and test it.

I have to admit that it crossed my mind to just walk away once I tightened the hoses in place.  I mean things had been going so well up to this point, why risk screwing up an otherwise great day by actually testing my work??

Even though there was a certain seductive logic to that thought, I climbed up and started the tractor anyway.  Then, leaning way over to the other side so the bulk of the engine was between me and the cylinder, you know, just in case I had done something spectacularly wrong, I very slowly eased the loader bucket off the ground.

It came up a couple inches without doing anything funny or making any weird noises, so I eased it up a little more. Eventually I was at full extension and no longer trying to keep the engine between me and the cylinder.

In fact I lowered the bucket and raised it again several times, starting very slowly then getting faster as nothing disastrous seemed to be happening and my confidence started to recover.

In the photo above I’ve left the bucket at full extension for several minutes


while I carefully checked for hydraulic oil where it didn’t belong.

Nope, everything was staying dry!

But the truth is, in this configuration the high pressure is on the far side of the piston and not against the back of the gland, which is where the original leak was in the first place.

So I lowered the bucket to the ground, then, with more than a little trepidation, used the bucket to lift the front tires. This put the pressure between the piston and the back-side of the gland and is what I was doing when I first saw the initial leak weeks ago now.

I left the tractor like that, propped up on the bucket, and watched for drips. Eventually I started breathing again as the hydraulic oil seemed to be staying where it was supposed to.

By now I was cocky enough to lower then lift the tractor with the bucket several times, even going so far as to up the RPM’s (The hydraulic pump is direct drive.) and push past the limits of the preset max-pressure-bypass in the valve-body, the last chance for things to go horribly wrong.

But they didn’t!

I was so stoked by my success that I even considered dropping the steering cylinder (To get it out from behind the battery box so I could reach it) to see if I could stop the leak there where the one hose attaches to the cylinder; but why risk ruining an otherwise glorious day??

That can wait for another time. . .



2 comments:

  1. Well that one repair cylinder is good for another 50 years.

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    Replies
    1. That might be asking a little much of my "expertise". If it lasts for 50 hours of diggin' and pushin' and liftin' I'll call it a success.

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