Dressing Up A Scratched Cylinder Rod???

[Wayne County Hose]

Doug,

You don't have to justify your actions to anybody but yourself. It is very easy for many people to be a "coach", do it this way or that way. But, when you put the ball in their hand, they run in a totally different direction.

If you need a hand with anything, give me a call.

Andy.

 

[Dougster]

Doug, You don't have to justify your actions to anybody but yourself. It is very easy for many people to be a "coach", do it this way or that way. But, when you put the ball in their hand, they run in a totally different direction. If you need a hand with anything, give me a call.
Andy.

Thanks Andy. Like I said before, any time you want to relocate up here to crazy old Taxachusetts, just let me know!

JB is a good man and if my actions in this situation are confusing to him, he deserves a good answer. But in the end, it all boils down to economics. You folks here... and my local cylinder repair guy... convinced me that a temporary patch was not a great idea. Likewise, the possibility of a seal eventually letting go on a jobsite was not a pleasant thought at all. In the end, to my great surprise, the Bradco replacement part was not insanely expensive. To me, this suddenly became a complete no-brainer.

This might have turned out very different if my tractor was strictly for personal use... and if I lived in a place where cylinder repair guys were on every corner and labor rates weren't threw the roof. I envy you guys who have access to cheaper, trusted, high-quality resources.

Dougster

 

[tlbuser]

This might have turned out very different if my tractor was strictly for personal use... and if I lived in a place where cylinder repair guys were on every corner and labor rates weren't threw the roof. I envy you guys who have access to cheaper, trusted, high-quality resources.

Dougster

Glad you found an option you're happy with. After all, individual happiness with any situation is the most important part.

 

[Dougster]

Glad you found an option you're happy with. After all, individual happiness with any situation is the most important part.

Especially when it turns out to be my least expensive option (for a permanent fix) as well.

Dougster

 

[john_bud]

The main problem is the awkwardness of dealing with the long hard-chromed rod (without damaging it) and the fact that I currently have no mounted vise of sufficient strength (and mounting strength) to take a torque of 785 ft-pounds (+/-) in any plane. I'm sure I'll figure something out, but right now I'm lacking in that capability.

And yes, despite my generic peanut butter-based diet, I am WELL over 100 pounds! But at the same time, let's please not forget that I am handicapped since birth with a semi-useless left arm. What you guys do every day without a second thought can be a project requiring major planning and special tools for me... and even then, a day or three of swelling and intense pain if I mess up.

Dougster

As I stated before, if you don't have a way to fixture it, put it back on the hoe. Protect the rod with a towel and wood blocks. Hold it down with a ratchet strap. The wood blocks need to be directly under the strap or you may bend the rod. (Shouldn't exceed the elastic limit, so it should be OK - but why borrow trouble). Is the spec on that rod's piston nut really 785 ft-lb? That would seem to be more of a spec for a 5-6" cylinder. Oh well, the MFG should know.

As it seems you don't have freedom to beef it, cut the cheater bar shorter so your weight will be giving the correct torque. I call that the "sit on it" method.

If the spec is 785, your 3/4 impact with the air pressure turned down (65 psi to the tool?) will probably be close. Do it with the rod on the hoe and then finish up with the cheater bar. Don't forget the loctite! You don't want that nut to come off.



In my experience, hydraulic cylinders rarely let go in a catastrophic manor. They start to weep, then drip, possibly dribble, but I haven't seen a rod seal blow out without warning and turn into a gyser. I'll post some pictures of rods with chips that don't leak and have lots of hours on them. But will have to go out to the shop to snap them.

These are some pics of a recent cylinder repair. Take note of the piston ring compressor used to compress the seals so they can be slid into the cylinder. New seals are TIGHT and won't want to just slide in. Slather with hydraulic oil to aid. Your hoe is fairly new, so it may be tight on the remove too. Use a ratchet strap to pull it out, if need be. You may have to bounce the rod into the cylinder the same way a hammer head is set on a new handle. You don't whack it, you lift and drop the cylinder letting inertia be your friend and allowing the rod to drop down. For a 4 1/2" cylinder I had to improvise and used the "A" frame of a trailer tongue to support the cylinder while lifting and dropping. You may need to think about rigging up something similar. I think you could wrap a 2" ratchet strap around the cylinder/rod and get it in that way. Apply pressure and if it is stubborn tap with a rubber mallet or hammer handle. Oh, and don't forget to double check that all the parts are on the rod. I forgot the gland nut and had to take everything apart before!

 

[Soundguy]

I'm glad you didn't jbweld it.

I've seen paint take out a hyd system cuz someone was sloppy when painting and painted a rod and it got past the wipe and seal. i can only imagine what jbweld would do..

Soundguy

 

[Dougster]

As I stated before, if you don't have a way to fixture it, put it back on the hoe. Protect the rod with a towel and wood blocks. Hold it down with a ratchet strap. The wood blocks need to be directly under the strap or you may bend the rod. (Shouldn't exceed the elastic limit, so it should be OK - but why borrow trouble). Is the spec on that rod's piston nut really 785 ft-lb? That would seem to be more of a spec for a 5-6" cylinder. Oh well, the MFG should know. As it seems you don't have freedom to beef it, cut the cheater bar shorter so your weight will be giving the correct torque. I call that the "sit on it" method. If the spec is 785, your 3/4 impact with the air pressure turned down (65 psi to the tool?) will probably be close. Do it with the rod on the hoe and then finish up with the cheater bar. Don't forget the loctite! You don't want that nut to come off.

Torque specification is the midpoint number right out of Bradco's instruction manual... albeit for the assumed nut size for the 2" shaft. I'll verify once I take it apart.

I've thought about putting the rod back on the backhoe to assist in torquing the nut. That may or may not be a wise or workable idea. Hopefully, I'll find someone to help with that critical step. Otherwise, I am not against buying a much larger vise. I just have to figure out where I can mount it that makes sense for that kind of torque. I keep thinking there is a way to use one of my HD FEL buckets. It would be great to find a large vise that could somehow be effectively clamped onto the massive CAT skidsteer bucket or even my 78" heavy-duty KMW bucket.

Use of Loctite was not mentioned by the dealer. He said that the nut is formed with a crown of some sort to lock it securely onto the rod. He did mention that deforming (i.e., restoring) the crown might be necessary after numerous removals... but that it shouldn't be necessary this first time. I'll ask him again about using the Loctite next time I see him. As always, I am concerned about potentially contaminating the hydraulic oil.

It would certainly be nice to use the monster 3/4" air wrench in lieu of buying a giant torque wrench or pipe & spring scale... and I must admit that the tolerance on the torque setting is very high (+/- 100 ft-pounds)... but I don't trust a mere wrench setting or air pressure adjustment without some other form of verification. At least with my trusty, older 1/2" air wrench, I've been known to end up with a bit too much or too little torque just relying on such seat-of-the-pants adjustments.

In my experience, hydraulic cylinders rarely let go in a catastrophic manor. They start to weep, then drip, possibly dribble, but I haven't seen a rod seal blow out without warning and turn into a gyser. I'll post some pictures of rods with chips that don't leak and have lots of hours on them. But will have to go out to the shop to snap them.

No need for more pix. I understand and accept what you're saying. All I ask is that you consider the remote jobsite issue with my "homeowner" clients typically looking on. What is a laughable nuisance oil leak at home is a catastrophic Exxon Valdez relived to these "environmentally conscious" folks. Add to that the need to stop and repair (as I had to do recently on an FEL control valve leak) and there goes the schedule... as well as the client's confidence in your work.

In the case of the control valve leak, I had to promise the client that I would rent another machine if we lost more than one day. Turned out that I only lost half a day (by working extra late the next day)... but that leak could have cost me a small fortune in rental fees... and taught me a hard lesson about making sure that my machine is in the best condition possible for every paying job.

Dougster

 

[Dougster]

I'm glad you didn't jbweld it. I've seen paint take out a hyd system cuz someone was sloppy when painting and painted a rod and it got past the wipe and seal. i can only imagine what jbweld would do..
Soundguy

Yeah, I don't think I'd have taken that approach. Silver solder would have probably been my preference in terms of a temporary repair... but I am pleased that the replacement rod was not crazy overpriced. The whole temporary repair concept quickly became a moot point.

Dougster

 

[Wayne County Hose]

Doug, no need for loc-tite in this application. Anyway, do me a favor, when you do tighten this nut, touch it and tell me how hot it is from the friction. And what does heat do to loctite? With these locking nuts, if they are going to come loose, loc-tite is not going to do a dam thing to stop it.

Do you want a real nice, sturdy, cheap, and easy to make vise mount? Get a piece of steel, 2" o.d. square tube, 1/4" thick. Mount the vise to this, stick the tube in your class 3 receiver. Instant stable vise for under $20.

Do not, DO not, DO NOT use an impact wrench on the nut. This is also a lock-nut, which changes everything. First of all, to say that "My impact says it develops 1000 ft. lbs. of torque so I can torque stuff to 1000 ft. lbs." is just ignorant. If your impact says 1000 ft. lbs., the average guy is lucky if he's getting 400 out of it. These impacts are rated in test lab conditions. With 1/2" air lines and screw type compressors with an almost unlimited supply of constant 120 p.s.i. air. Did you ever put an air gauge right at your gun and see the pressure drop when you pull the trigger? You would be shocked. Try it.

Don't get too stuck on getting this exact torque. Not only me, a small shop, but also the large shops I know and deal with, do not have anything to set the exact torque with. There are excavator cylinders which get tightened to over 10,000 ft. lbs. Is there a torque wrench for that? of course not. There are ways to get it close, but none of us are going to spend $20,000 on the equipment to do it.

 

[Dougster]

Doug, no need for loc-tite in this application. Anyway, do me a favor, when you do tighten this nut, touch it and tell me how hot it is from the friction. And what does heat do to loctite? With these locking nuts, if they are going to come loose, loc-tite is not going to do a dam thing to stop it.

Do you want a real nice, sturdy, cheap, and easy to make vise mount? Get a piece of steel, 2" o.d. square tube, 1/4" thick. Mount the vise to this, stick the tube in your class 3 receiver. Instant stable vise for under $20.

Do not, DO not, DO NOT use an impact wrench on the nut. This is also a lock-nut, which changes everything. First of all, to say that "My impact says it develops 1000 ft. lbs. of torque so I can torque stuff to 1000 ft. lbs." is just ignorant. If your impact says 1000 ft. lbs., the average guy is lucky if he's getting 400 out of it. These impacts are rated in test lab conditions. With 1/2" air lines and screw type compressors with an almost unlimited supply of constant 120 p.s.i. air. Did you ever put an air gauge right at your gun and see the pressure drop when you pull the trigger? You would be shocked. Try it.

Don't get too stuck on getting this exact torque. Not only me, a small shop, but also the large shops I know and deal with, do not have anything to set the exact torque with. There are excavator cylinders which get tightened to over 10,000 ft. lbs. Is there a torque wrench for that? of course not. There are ways to get it close, but none of us are going to spend $20,000 on the equipment to do it.

Thanks Andy - Are you sure you don't want to relocate up here to Taxachusetts??? On your specific points:

1) What you say sounds reasonable. Out of great respect for both you and JB, I'll ask the dealer and his top mechanic (who have worked on these specific Bradco cylinders 100's of times before) and let them call that shot. I note that there is no mention of either use (or non-use) of Loctite or restoring the nut's crown in the Bradco instructions.

2) Good idea on the hitch-mount vise! Now why didn't I think of that! With my new Putnum XBR Class 5 hitch, that could work really nice!

3) I hear what you are saying on the impact wrench. I went out of my way to do my research and avoid those wrenches with claims that were exaggerated, misleading, mis-stated or just plain silly. So far, this beefy "take no prisoners" monster wrench has never let me down once... even on very large snowplow nuts and bolts that could barely be budged any other way. Still, the issue of torquing accuracy remains...

4) Being a hideous, stubborn old mechanical engineer, I read a manufacturer's spec and I take it literally and dead seriously. In my career, I made my employers an awful lot of money troubleshooting equipment all over the world by simply following manufacturer's specs when others didn't. I hear what you're saying, but I still want to get it as close to spec as reasonably possible.

Dougster