What's new
By:
Filters

Anyone know JCB telehandlers? Steering problems....

Alright....new "issue".

After getting the cylinders back together and waiting for the pin to come in, the last fluid I needed to tackle was the hydraulic. So I drained the tank and decided to pull the side cover to see if there was anything concerning inside. Kind of glad I did as the suction strainer/filter was pretty gunked up with what I'm assuming are pieces of the rotten seals I found in the cylinders and some other unidentifiable bits. The main filter was really clean and I'm guessing had recently be replaced and was OEM JCB so I opted to leave it instead of using the chinese knockoff I got from Amazon.

Of course, the gasket for the access cover was not in the best shape. Could have gotten away with using it, but decided it was worth sourcing a new one as I shouldn't need to get back in here in there for a while and don't want to risk it leaking and having to drain the tank again. As it turns out, my particular year uses an less common 10-hole cover where almost all the the other ones use an 8-hole that's used on just about every other JCB machine. I luckily I messaged a seller on ebay to see if he could get one and while he couldn't, he was able to give me the part number for it and I managed to find the only one available. After USPS lost it for a few days, it finally showed up yesterday and I got it installed and put a couple buckets of fluid in the tank.
1717517516933.png


That leads me to today. I got my mower wedged in a precarious place and needed to drag it out. :homer: The tele would have been perfect, but I quickly realized I have zero hydraulics, including brakes....which could have been ugly if I hadn't noticed when I did. :laughing:


So, I'm assuming I lost prime on the pump or something when I drained the tank? Is there some trick to getting it flowing again? I didn't want to sit there and keep running it with no flow and risk fucking something up more than it probably already is.
 
bgaidan said:
So, I'm assuming I lost prime on the pump or something when I drained the tank? Is there some trick to getting it flowing again? I didn't want to sit there and keep running it with no flow and risk fucking something up more than it probably already is.
Click to expand...
Crack a fitting on the pressure side and apply shop air to the vent?
 
So I pretty much have all the bugs worked out of this thing now. Been using it as needed for the past couple months and it's an awesome little machine.

So, time to spend a boat load of money on it!

There have been a few local auctions that were loaded up with all the usual Chinese implements. I managed to score a set of Hydraulic forks for about what I would have paid retail for a regular fork carriage. Also got this goofy tree puller thing because it went cheap enough to justify fucking around with it. If nothing else, I can repurpose the frame and hydraulics for something else.

1722392180030.png


And then scored this fork grapple over the weekend. I was planning on getting a regular brush or root grapple, but this was also cheap enough to justify fucking around with it. I suspect it'll work for 90% of what I'll need a grapple for around the property and with the forks, I won't have to swap back and forth as often.
1722392323417.png


Scored an 84" bucket for about $450. She's a little too big for the 790, but should be perfect on the JCB.
1722392309342.png




Of course, I still need to make the skid steer quick attach adapter for the machine as these attachments are all pretty much useless without it. :laughing:

Been trying to fin a local place that can CNC burn 1" plate. I think I finally have a couple leads that I need to call this week. Which also means I need to finish tweaking the CAD file and figure out what angle I wan to set the hook and holes at on the JCB side. I think the stock geometry doesn't let you tilt attachments far enough back so I either need to kick the bottom holes outward a bit more, or add a taper to the outer face of the adapter mounting plates to add a bit more backward tilt. There's plenty of forward tilt - it'll let the forks go a good 15-20 degrees past vertical so not worried about losing angle in that direction.
 
Unrelated but related....

I also picked up one of these "fed bunk sweepers" at the auction over the weekend. Kind of got caught up in the moment and it was cheap - like $300 cheap and I figured the mounting plate, hydraulic hoses and couplers and motor were worth more than that.

So now I'm stuck with the dilemma of trying to flip it - they retail for about $2500 so I could probably quickly get $800-1k for it - or figure out something cool and possible useful to do with a presumable low power hydraulic motor. Possible a back scratcher for your mom? :flipoff2:

1722393964827.png


1722393997749.png

1722394013768.png
 
Looks like it's basically a mini sidewalk sweeper attachment.

I'd hook it up as is and drive around your property until you find something it does well. :laughing:
 
I was considering converting one of my forks to a grapple fork, since I'm up to three sets so far.

I think it would be worthwhile to make beefy bolt-on "somethings" to lock the forks in position because it's so easy to wreck the little spring loaded top locking pins, and it would be super annoying having those forks slide around while you're doing stupid grapple shit with them.
 
Alight....found someone on ebay that was selling the next size up JCB q-fit plates and was willing to cut my smaller ones. Ended up getting two sets for $550....not horrible for 1" thick plates.

Kept the design pretty simple. I was going to do multiple bottom holes so I could adjust the angle, but it was going to make the plates way bigger and looked goofy. If I did my math right, this should give me about 25 degrees more upward "curl" compared to the stock carriage.

1723154812114.png


And Vevor adapter plates FTW. You can get just the actual machine plates for about $80 on amazon and ebay. There are a dozen different "brands", but they're all the same thickness (8mm) and all weigh the same so I don't think there's much difference in quality.

But then vevor sells the set for $126 so I get a 1/4" adapter plate for an extra $45. :smokin:
1723154866852.png


I already have all the other steel I need to make the adapter. Everything should be delivered by the middle of next week so hopefully I can knock it out by next weekend.
 
Dethmachinefab said:
Usually if one starts leaking on an old machine, most others will follow. Even more so with something that has sat for a while.

I've noticed a few drips from my crane telescope cylinder. Not looking forward to pulling that out with all the chains, cables, boom and associated bits.
Click to expand...


Just want to say fuck you again. :flipoff2:


Machine had been almost entirely leak free since I did the 2 cylinder rebuilds. Noticed some oil yesterday after moving it around a couple times. Sure enough, the main lift cylinder is now weeping. Given how fast the other once really started puking, gonna go ahead and order the kits for the lift and the remaining tilt cylinders. Supposedly the PO had just rebuilt the two steering cylinders so once I do these two, that will mean they're all done.

Once I get the SSQA adapter done, the next and hopefully final step will be hitting with a coat of paint.
 
bgaidan said:
Just want to say fuck you again. :flipoff2:


Machine had been almost entirely leak free since I did the 2 cylinder rebuilds. Noticed some oil yesterday after moving it around a couple times. Sure enough, the main lift cylinder is now weeping. Given how fast the other once really started puking, gonna go ahead and order the kits for the lift and the remaining tilt cylinders. Supposedly the PO had just rebuilt the two steering cylinders so once I do these two, that will mean they're all done.

Once I get the SSQA adapter done, the next and hopefully final step will be hitting with a coat of paint.
Click to expand...
Sorry. :flipoff2:

I've got two machines with seals due to be changed and not looking forward to it.
 
Alright...so I was moving sawmill slabs around in the pole barn over the weekend and just as I got the last pile put back in place I felt a little spray on my arm. Sure enough, the fucking lift cylinder blew it's gland seal(s). Got it back up to the shop and by that point when I lifted the boom it was spraying a solid stream straight out the front of the gland. :laughing: New seals will be delivered tomorrow...

So started pulling the cylinder apart tonight. Got the gland off without a problem, but now I can't get the piston to move. I ran the gland back in a few threads and started the machine and ran the piston as far out as it would go with pressure, but it's still got another 6-8" to go. I pulled a spare forklift in front of it to use an an anchor and tried pulling it with a ratchet strap and it wouldn't budge.

I'm thinking it's likely this burst protection valve - that's there to prevent the boom from dropping if one of the hoses blows - which is pretty much what it thinks is happening.

Anyone know how these work? I'm paranoid that taking it off is going to lead to a bunch of small spring loaded parts fucking off at mach 20. There's not much in the service manual about them. Gut feeling is to attack the big "nut" and leave the shit at the end alone as that's probably the adjustment for it....but I'm still worried about fucking it up. :laughing:

1724202068603.png
 
That valve needs pressure in the other direction to allow flow (won't let anything out the rod side if there's no pressure on the non-rod side) and vise versa.

I've bent a few sets of tilt cylinders at work because of this.

I'm confused though, are you saying you had the gland completely off and still couldn't pull the rod out? Is it because there are two lift cylinders and you only took apart one (so it's the other one fighting you) ? Trying to do this without unpinning the cylinders...

If there's only one cylinder and the gland is off, then it's open to air and the only thing you would have to fight is vacuum.
 
Muckin_Slusher said:
That valve needs pressure in the other direction to allow flow (won't let anything out the rod side if there's no pressure on the non-rod side) and vise versa.

I've bent a few sets of tilt cylinders at work because of this.

I'm confused though, are you saying you had the gland completely off and still couldn't pull the rod out? Is it because there are two lift cylinders and you only took apart one (so it's the other one fighting you) ? Trying to do this without unpinning the cylinders...

If there's only one cylinder and the gland is off, then it's open to air and the only thing you would have to fight is vacuum.
Click to expand...

There's only 1 lift cylinder. The other is for tilt compensation and is effectively passive - when the lift cylinder lifts the boom, the tilt compensation cylinder moves with it and pushes fluid to the tilt cylinder on the carriage to keep it level.

I'm pretty confident that the burst protection valve is what's holding it back. I just wasn't sure how it works or if it was safe to just remove without fucking it up. I also didn't want to yank on the rod too hard and have it fly out and get fucked up.
 
Dethmachinefab said:
Pulling it to break the vacuum is usually needed.
Click to expand...

I broke a ratchet strap yanking on it last night. The hook fucked off an put a gash in my elbow so I decided to call it a night. :lmao:

I know it's a bigger cylinder and it'll take more oomph to get it moving, but I figured with the hoses disconnected it'd budge with a few hundred pounds of pull form a ratchet strap.
 
Well, that wasn't bad. I heard it burp a little bit as I pulled that valve out. Piston moved freely after that. Seal kit is out on the mail truck right now so hopefully I'll be able to get it torn down before it arrives and get it back together this afternoon. :smokin:
 
Last edited:
Got the rod pulled and set up on the rebuild bench and used the proper socket to remove the piston. :laughing:
1724251722107.png


Seeing a common trend in all the cylinders from this machine. Gland seals are toast and pretty much disintegrate upon removal. Every other seal looks good as new.
1724251881186.png

Little more cleanup to do on the gland and then just waiting on the mail to arrive which should be in the next hour or so.
 
By taking shit apart before you got the parts in hand the odds of the parts being wrong went way up. :laughing:
 
bgaidan said:
Not really when the part had completely failed and couldn't be used as it sat.
Click to expand...
I'm still superstitious.

When I try and make shit happen quick it always goes wrong. Parts that I've been meaning to get around to installing for 6mo-6yr always fit.
 
arse_sidewards said:
I'm still superstitious.

When I try and make shit happen quick it always goes wrong. Parts that I've been meaning to get around to installing for 6mo-6yr always fit.
Click to expand...
I like it when you're wrong. :flipoff2:

Seal kit looked good. Was missing one backer for the o-ring on the outside of the gland, but the old one was perfectly fine so I just reused it. And, of course, there was an extra backer for either inside the gland or the piston that the old one didn't have, so I left it out. 🤷‍♂️

1724260053496.png



Back in business.
1724260080518.png




Now the question is, do I go ahead and do the tilt cylinder or ignore it and wait for it to fail at the most inopportune time? :laughing:
 
bgaidan said:
I like it when you're wrong. :flipoff2:

Seal kit looked good. Was missing one backer for the o-ring on the outside of the gland, but the old one was perfectly fine so I just reused it. And, of course, there was an extra backer for either inside the gland or the piston that the old one didn't have, so I left it out. 🤷‍♂️

1724260053496.png



Back in business.
1724260080518.png




Now the question is, do I go ahead and do the tilt cylinder or ignore it and wait for it to fail at the most inopportune time? :laughing:
Click to expand...
Of course...put it off! Lol
 
Muckin_Slusher said:
Shush!

It's funnier this way.
Click to expand...
Are you not entertained? :flipoff2:




I probably AM going to tackle it tonight. It'll be more fun than the other projects I should be working on. :shaking:

What's going to suck about this one is the pin is probably not going to want to come out. I had someone here a few weeks ago picking something up and he had the same machine. He said when he had to pull that cylinder that the pin was so seized that he ended up taking a quickie saw and slicing the pin on either side of the eye and then burning the rest out...and then had to make shims to make up for what got notched out by the saw. :shaking: The pin is only greased at the eye so the part that sits in that link on either side never gets lubed and just seizes up over its life.

I'll probably unbolt the trunnion again, drop the tube and leave the rod hanging from the machine while I rebuild it. I already had the trunion clamps off and the cylinder laid down when I had to pound the pin out for the extension cylinder.

1724267786473.png
 
You must log in or register to reply here.
Top Back Refresh