B1630 FEL bucket cylinder rebuild

[Thatoneguy]

Since the my b7200 is down waiting on a loader valve, ive pulled off a bucket cylinder to rebuild one at a time... and like anything else i do, it cant be simple. I was able to aquire two bucket cylinder seal kits from my local kubota dealer. The kits seem old and one looks like its missing parts but thats a different problem i can deal with later. When pulling the kit apart, it has instructions that say its for any 1630 cylinder after sn 22004922. Of course my FEL has sn 22002780. Another note on the instructions talks about the kit fitting both bucket and lift cylinders that have been converted to the "new style".

I used a caliper and found the rods on both cylinders (lift and bucket) and a few mm different from each other. One major difference ive noticed with the kit is the rod nut.. the cylinder i have has a 1-1/8" nut whereas the kit comes with a much smaller one. Is that the only difference? How would i know if the cylinders have been converted? Using the caliper the seals seem to match the cylinder gland size. I understand the nut should not be re used but is that just a locktight fix or something to do with tensil strength like head bolts on an engine? I may have to go to a hydraulic shop to have orings matched but im already 150 bucks into these seal kits and if theyll work id rather get it back together sooner than later.

I tried to look up the service bulletins related in the instructions but wasnt able to locate anything.

As always, thank you for the help.

 

[Thatoneguy]

I forgot to add a couple pictures if it helps

 

[Matt Ellerbee]

Can’t help on the seal kits, but my hydraulic shop I use, have swapped my wrong seals/o rings for the proper ones at no charge. They just added my stuff to their inventory.

And usually you will be $ ahead if you just take them the cylinders to be rebuilt vs. buying overpriced seal kits from dealer.

 

[Thatoneguy]

Yeah i may pull all the seals from this and all the seals from a lift cylinder and see about matching them at a hydraulic shop. Im going to try to return the one incomplete seal kit anyways... a local shop here in southern california wants 280 per cylinder to rebuild and another shop said 250 per. I have 5 to do... 4 minimum. I will probably take your advise and at least get the seals from a shop. I was quoted for those to be around 30 bucks or so per

 

[Edke6bnl]

Yeah i may pull all the seals from this and all the seals from a lift cylinder and see about matching them at a hydraulic shop. Im going to try to return the one incomplete seal kit anyways... a local shop here in southern california wants 280 per cylinder to rebuild and another shop said 250 per. I have 5 to do... 4 minimum. I will probably take your advise and at least get the seals from a shop. I was quoted for those to be around 30 bucks or so per

I was quoted $195 to $230 for cylinder rebuild and in the high desert So. California. I bought the kit fromvColeman Equipment, Inc. Online. My first attempt at rebuilding a Hyd cyl. for my b7800 worked out great. I bought two kits but just did one cylinder and so far no leaks either cylinder.
Kubota Hydraulic Cylinder Seal Kit
Item #75545-64600
Each: $44.41
Qty: 2

 

[Vigo]

I've done seals on about 5 cylinders so far and on average the hydraulic shop i'm going to is costing $35-40 for the seals for each cylinder.

I did look into the kubota seal kits originally but i thought the price was outrageous for what it is, so i went and matched em up at a local shop and.. yeah, i still think the dealer price is outrageous!!

I believe the whole not reusing the nut thing is because it's a 'prevailing torque nut' aka locknut where the threads are distorted a little when built so it goes on tight and resists vibrating loose over time. I personally think you can reuse them as long as they are spinning on and off ok (no NEW thread damage over what it has built-in). I'm an ASE Master Technician so I've certainly dealt with a lot of torque-to-yield fasteners and they are only getting more common, but this is not TTY, it's just that any time a 'locknut' is used the factory procedure always says not to reuse it.

There's a real interesting video out there by a company called Nord-Lock that shows different types of nuts/retaining systems vibrating loose on a test rig. I dont think it's all that applicable to the rod nut on a hydraulic cylinder, but it's an interesting video nonetheless!

 

[Thatoneguy]

Wow, that is a pretty interesting breakdown on those lock nuts. Luckily i was able to return all the wrong parts i have. Messics has the seal kits i need, they are pricey but includes new nuts and shipped to my door makes it easier than trying to source them at the moment. The lift cylinders will need to be matched at a shop for sure but thats a project for another day. All of this is great info. Thank you all again.

 

[TheOldHokie]

Wow, that is a pretty interesting breakdown on those lock nuts. Luckily i was able to return all the wrong parts i have. Messics has the seal kits i need, they are pricey but includes new nuts and shipped to my door makes it easier than trying to source them at the moment. The lift cylinders will need to be matched at a shop for sure but thats a project for another day. All of this is great info. Thank you all again.

When i had these problems a few years ago I simply bought new cylinders. Considersbly less than the rebuild quotes you received.

1.5 bore x 18 stroke hydraulic cylinder, welded cross tube double acting cylinder | Magister Hydraulics

1.5" bore x 18" stroke cross tube hydraulic cylinder 3500 PSI. Heavy-duty hydraulics, 2-year warranty, free ground Continental US shipping. Magister cylinders manufactured using steel piston and steel threaded gland with wear rings for long life. Welded cross tube ends, honed cold-drawn tubing...

www.magisterhyd.com

1.5 bore x 16 stroke hydraulic cylinder, welded cross tube double acting cylinder | Magister Hydraulics

1.5" bore x 16" stroke cross tube hydraulic cylinder 3500 PSI. Heavy-duty hydraulics, 2-year warranty, free ground Continental US shipping. Magister cylinders manufactured using steel piston and steel threaded gland with wear rings for long life. Welded cross tube ends, honed cold-drawn tubing...

www.magisterhyd.com

Dan

 

[Thatoneguy]

I got the new seal kits in today and they appear to be the correct ones. Although according to the instructions it looks like i have the sperry-new holland cylinders... which says i need to replace the gland and piston. Is that really necessary? It seems rediculous to me but then again im struggling to do something that many others have done already.

Im to the point of junking all of them and buying new ones as suggested by theoldhokie.

 

[TheOldHokie]

I got the new seal kits in today and they appear to be the correct ones. Although according to the instructions it looks like i have the sperry-new holland cylinders... which says i need to replace the gland and piston. Is that really necessary? It seems rediculous to me but then again im struggling to do something that many others have done already.

Im to the point of junking all of them and buying new ones as suggested by theoldhokie.

The only reason I can think of for replacing the gland nut and piston would be the new seals are not a proper fit in the old parts

Dan

 

[Vigo]

Unless it is referring to a '1st design, 2nd design' kind of thing where the design of those pieces changed somewhere during the production run and the parts you have only fit the '2nd design', then I don't know why they would say that.

If the seals fit, i would ignore it and carry on. Really, the stakes for failure here are pretty low. What happens if the rebuild fails? Internal leakage, ok it performs badly and you notice and fix it. External leakage, ok it leaks and you notice and fix it. It's not like the cylinder becomes a bomb. The fluid system doesn't 'store' much energy since fluids don't compress much and hoses don' stretch much so even if the gland ripped off the end of the cylinder it probably wouldn't even make it to the end of the rod. It would be like a water tank popping. A big PUH and then fluid everywhere. There's no real danger to failure here, and the most likely form of failure is just leakage. So just keep trying until something actually proves it won't work, or until you're tired of it. Or until it just works!