Bendpak cylinder rebuild

[ml504]

The cylinder on my bendpak hd-9xw developed a leak so I purchased the seal kit to try before replacing the entire cylinder. Have anyone on here done this and can offer some points or a how-to?
Thanks,
Matt

 

[Spareparts]

Leaking around the rod???

 

[pstnbly]

I've repacked many cylinders, but not specifically that one. It isn't that hard. my advice is when removing the piston to look over the piston and gland nut carefully and make sure to remove any retaining pins first. Sometimes there are pins through the gland nut or piston puck that are very hard to find and if you try to remove them with them still pinned you will destroy the shaft. Other than that it's straight forward, just be carful the parts can be sharp and damage the seals. You can heat the Teflon seals in very hot water to help.

 

[padroo]

You may find some scoring on the piston. Do a good clean up and lubricate everything with hydraulic fluid on reassembly. Lay the old parts out in the order you remove them and identify the corresponding new part.

 

[brownbagg]

was you able to buy a seal kit, bendpak told me they dont sell rebuild kits and I have to buy a complete new clyinder

 

[padroo]

Most of those seal kits aren't much more than a handful of O rings and some nylon backers.

 

[Jay_mc1]

I have a local place, (45 miles away) that I have had work on over ten cylinders in the past 5 years. 8 out of the 10 were from my big john tree 90' tree spade. Most the time it was just seals, but 1 time they had to build me a new piston because it was bent, and another time they had to build me a new outside case because it had a slight bend and crease in it. New from big john was going to cost me right at $2000, the re-used my piston and built me a new case and seals for $600. The last cylinder I took them was from my bendpak 12000 4 post lift. It did take a little longer To get the seals but they did an amazing job as always. If you have problems finding the seals, it might be worth giving my local shop a call, my bendpak lift is pretty old (maroon and yellow in color) and they were able to get them although I doubt it was from bendpak. Let me know if you would like their number

 

[macdabs]

MY bendpak lift leaked from day one. They sent me a new cylinder and said they are not worth repairing. The new one leaked year later, after the warranty is out , 4 post HD 9W rack . A mustang is stored on it almost all the time operating up and down 5 times a year max. I have a rotary in ground that is going on 40 years old and a rotary above ground 20 plus with no leaks .

 

[matt_i]

I've sourced all of my seals from Hercules (formerly Hercules Bulldog) for forklifts. I had to buy them thru Motion Industries since I had no "direct business" account.

http://herculesus.com/

Not sure if they have the right kit but I am guessing they do.

Its always good to understand why the former seals failed, if there is any rough spots in the chroming I have used a 600 grit diemaker's polishing stone to smooth them out. The seals will glide over/thru a divot as long as its smooth. Your finger and fingernail are very sensitive in figuring out what's good and bad.

If its a traditional threaded cap, there are a couple of challenges. First may need a special tool to unscrew the cap. I have always made these in the shop over using things like punches and chisels to scar them up.

Being a single acting cylinder it may have a u-cup seal instead of an o- or quad-ring. You have to invent some way to get those past the internal threads on the body without tearing them up. I have done three things, either machined them out of PVC pipe, brazed a ring of steel banding wrapped in a loop, or used a piece of .010" (iirc) shim stock wrapped like a funnel to guide the soft parts past the "teeth". As above, a generous coating of fresh/clean fluid is your friend.

 

[RWorth]

Problem with storage lifts is the piston rod is exposed all the time instead of retracted where it is protected from dirt and dust. When the rod gets dirty and is retracted it eats the seals. If you have a machine with an exposed rod, it's a good idea to spray it with WD or CRC ,whatever you use in your shop, before you let the car down and occasionally while it's up. Your seals will thank you.

 

[ml504]

Thanks for the info. Bendpak said the seal kit was a 50/50 chance of fixing the problem. However, if it still leaked they would apply the cost of the seal kit to the purchase of a new cylinder ($480.00). The seal kit was $70 and as someone mentioned just a bag full of different sized o-rings. I use the lift more for storage so the rod is exposed most of the time. I will start lubricating it on a regular basis in hopes of preventing this from happening again.

I'll give it a shot and see what happens.

 

[rburke65]

How old is the lift that it is leaking?

 

[ml504]

3 years old....it gets used very little maybe twice/three times a month.

 

[Z2V]

I sure didn't want to hear that it's leaking after three years. I installed a BendPak HD-9 two weeks ago. On mine the piston is not exposed when the lift is up. It is exposed when the lift is down. Is this different from yours?

 

[575cat]

Easy too rebuild but you will probably find its a crappy bore , new cyl .

 

[rburke65]

Wow.....not too long of a life at 3 years old.

 

[Dr Stan]

Many equipment manufacturing companies do not build their own hydraulic or air cylinders or any other fluid power items. Before buying a new one from Bendpak see if you can find any info on the cylinder to track down the OM.

 

[brownbagg]

i dont think bendpak builds anything but just put together from other mfg.

 

[rburke65]

Maybe a rebuild kit from "China-R-Us"?

 

[ml504]

Going to try and start working on it mid week and will take some photos along the way. Definitely not too happy having to do this but it is what it is.

 

[ml504]

I got the lines disconnected and the lock ring at the end of the nut where it attaches to the bracket holding the steel cables. What is the best way to remove the large (1 1/2") nut? When putting a socket on it the rod spins with it and I'm not sure the best way to prevent the rod from spinning.

 

[macdabs]

Can you get an impact on it and just hold the cylinder with your hand and a quick burp with the gun? I cant remember for sure but I thought the cylinder end with the nut attached to a bracket that pulled the cables and you can remove the cylinder and the bracket together. Whatever you do don't use plumb pliers or vise grips on the cylinder .

Mac

 

[Art Butler]

My gland nut had no threads. The gland nut was held on by a round wire ring. Check to see if you have a small access hole in the cylinder.

 

[Z2V]

Mine has flats cut behind the threads that you put a wrench on. Like Mac mentioned you might get it with an impact. If at last resort you do use pliers, be sure to wrap the piston first so the pliers don't dig into the metal. I would use leather if available.
Good luck
HAPPY NEW YEAR

 

[tk76]

I had a similar leak with my Direct Lift 4 post cylinder. Bought a factory seal kit and took to a local hydraulic shop (NYC area). They charged me around $175 to reseal. Has worked great since with no leaks but does make a groan sound at times now that it didn't make before.

 

[ml504]

Just an update, I didn't have much luck with the seal kit. I ended up speaking with Jeff (VP of sales) at Bendpak and he sent out an entire new cylinder at no charge. I've read about the customer service at Bendpak but now have experienced it first hand. It's a rare thing to find a company that stands behind its products and goes the extra mile and just wanted to share this with fellow members here.

 

[padroo]

Good deal.

 

[r_egan]

I too have a BendPak HD-9 that started leaking two months after the 2 year warranty period. They were unwilling to replace the cylinder at no charged and instead sent me a rubber boot (looks like a CV boot) to install on the cylinder so that hydraulic fluid doesn't drip on my car.

I received the boot but no installation instructions. I assume i unbolt the shaft and slip it over. My question is - how do I get the shaft to retract into the cylinder? Can it simply be pushed by hand back into the cylinder?

 

[Z2V]

Assuming you have the runways landed on the locks and the cables disconnected just run the pump to bring the piston into the cylinder.

 

[r_egan]

Thanks Z2V. Do I need to disconnect the cables or can I remove the bolt and allow the shaft to retract far enough back to slip on the boot?

 

[Z2V]

You can remove the big center nut on the piston and just set all four cable aside.
BE SURE THE RUNWAYS ARE ON SAFETY LOCK. I don't at all mean to insult your intelligence but just a reminder.

 

[r_egan]

Z2V - I appreciate your concern for my safety. I will assure that the runways are on the safety locks before removing the nut.

Thanks again for your help.

 

[Z2V]

Good luck

 

[livinlife]

Yes, good luck.....