The Stovebolt Site Forums The Parking Lot Big Bolts Hydraulic Cylinder Help

I have a grain bed with hoist for my 1 ton. I figure most of the little bolts don't work with these, so that's why I posted on the Big Bolt.

Looks like a while back the PO broke the single hydraulic cylinder "lever hoist" and replaced it with two telescopic cylinders direct lift. Yeah, this is real overkill.

The surfaces are a bit rusty on one of the cylinders. I've never rebuilt this type of a hydraulic cylinder before and would prefer to send this out if it's possible. Is this something that I can take somewhere and have them refurbish / fix / etc... What else should they work on while I have my cylinders there? Would they also have the capability to rebuild the pump and valve? What kind of shop should I look for to send this to?

Thanks, and any help is appreciated.

Hy jhaa_lives, A good hydraulic shop can rebuild/repair all the components in the system, cylinders, pumps, filters, reservoirs, hoses and valves. If your cylinder rams have visible rust on them they should probably be rechromed, a very expensive process, you may be able to buy replacement cylinders of the correct size cheaper than repairing your old ones, I don't know what stores you have in your area that could supply them, Tractor Supply maybe, hope that helps.

depending on how bad the rust is, you can just polish it up with emery cloth. like 3b said any hydraulic place can do about anything. if its a sold shaft ram in the cylinder (whats the diameter of shaft) they can be remade pretty easy. last one had built was about 250 bucks... it wasnt chromed. just polished up in lathe. Remember, they run in oil.

Tractor shops should be able to handle it, or send you to whomever does thier work for them. look up the local John Deere & Case Tractor dealers in your area. If you're driving the rig just swing by and ask, might even be a quick fix they can do that day.

Thanks guys. Plenty of tractor stores here in the midwest. I'll see where they get there stuff fixed. The surface rust is light and I considered trying emery cloth but didn't know if this was the right thing to do. They are not chromed.

The pistons (rams) are telescopic (3 sections). From my memory, they are about 3 feet long. The inner most "piston" is about 3" diameter. The next one is about 4" diameter. They outer cylinder is about 5 to 6" in diameter. Fully extended it's about 7' long. How much do you think 2 of these could lift? (not taking into account the mechanical advantage they have by working at an angle)

I question if the cylinder is rusted or just the exposed shaft. If its the shaft simply remove the rust the best way possible. If you have disassembled the unit and it is rusted internally. you might have to replace it but fine emery cloth could go a long ways. I would doubt that replacement is necessary. Does it leak oil should be some guideline.

those type cylinders usually are on big gravel trucks and will lift about a bazillion tons...to figure it exactly its pump pressure times the square inches of cylinder.. 6 inch cylinder would be app 18sq inches times say 2000lbs pressure on pump....or 18 tons per cylinder on the 6 inch portion it would get less on smaller....so hehehe ya got plenty for one ton like ya said....

You have telescopic cylinders and if your able to post pictures of them I can probably help you. If you give me accurate info on the pump brand/model/type and body length with overhang I can figure the capacity for you. Assuming your truck is a "one ton" you have more than enough power but I'm happy to figure it for you if you furnish the above info. Truck equipment shops are also good repair shops for hoists and cylinders.

Thanks guys. I'm working on getting pictures linked of the cylinders, pump, and valves. I cleaned them up a bit last night and have some information on them. My memory was not quite accurate on the size, but these are still BIG cylinders for a 1 ton.

Cylinders - Extend to 65" (forgot to get unextended length). One has the number 266 stamped on the bottoms cylinder and both have 594 stamped on the stamped on the big cylinder seal and 593 stamped on the middle cylinder seal. The large cylinder is 4" OD, middle ram is 3 1/2" OD, top ram is 3" OD. Assuming a 2000 psi pressure, I'm looking at about 10 ton per cylinder. MUCH more than my little tonner will handle (3 ton max'ish).

Pump - Gresen Minneapolis Model "TB" cast into the unit, 12C is stamped under the model information. Serial number F3 is stamped. It looks like an aluminum body. The unit looks in good shape.

Valve - Gre-Sen Minneapolis 300 cast into the unit. E2 stamped on it. 3 13 2 cast into it (like a date stamped casting mark). The unit looks in good shape.

Got some photo's on the web.

http://www.yesterdaystruck.com/trphotos/a2041.jpg

Here's all the guts of the hdyraulics. Note the outside of the middle ram is BADLY rusted. It doesn't move very well. However, the smaller ram moves just fine. I'm looking for a place to refurbish these if possible.

http;//www.yesterdaystruck.com/trphotos/a2042.jpg

Here's the hydraulic pump and valve. Gresen seems to be a good name.

From the photo's they appear to be Glencoe's made in Illinois. They are very simple inexpensive cylinders and used an O ring seal so are made for low pressure of the Gresen pump. It is probably a vane style pump and operated at about 1000 psi max. They cylinder is so large that the load would move before the pressure ever developed very high so you good.

Unfortunately Glencoe no longer makes hoists and may not even be in business any longer. Do a Google on them for farm implements and the like.
The barrels were not chromed so I'd just go after then with emory cloth as previously suggested and clean them up if not pitted to badly. Hope this info is of some value to you.

This makes sense. The truck was built in the St. Louis plant. The Knapeheid bed was made in Quincy. The truck spent all it's life (until my purchase) in central Illinois. When the original hoist broke, they replaced it with something locally available... from Illinois.

How difficult is it to "unscrew" the caps and remove them? I can see that they are threaded onto the outside. I don't have a pipe wrench big enough. I'd like to get to the inside of the cylinders and hone them. If I can get to that point, then I can replace the O-rings myself.

How involved is it to replace the outer seal / wiper that is on the cap?

Thanks for all your help.

Easily done. Get yourself a chain wrench to remove the caps. When you get it apart it will more or less explain itself, not a complicated design.

OK, it was easy enough to take the caps off with the chain wrench. The rams have two brass "sleeves" at the bottom of them, I assume to help guide them in the cylinder. The brass is in good shape. Emery cloth on the rusty parts of the ram made the rust dissapear. Just some minor pitting here and there. Should I take it all the way down or is this sufficient?

Noticed what looks like a makers mark on the cap, it is the letter P inside a box. Mean anything to you?

The cap has what looks to be a pressed in seal. Metal base, with a rubber wiper, fibrous material ring, O-ring, then another fibrous material ring. The fiber rings look like an artificial leather. They set on either side of what appears to be a rubber O-ring.

Is this a seal that I can push out, buy a new one, and push it in? or do I have to buy all the individual rings and things to replace them back in the metal base?

Thanks for any help.

You can buy neoprene replacement packing seals for nearly any cylinder from a seal house or hydraulic supply. They are a floating style and seal w/o taking up the entire space originally used for the packing which is what the spacers you describe are doing. Just give them the ID/OD or take the old parts int to compare. Very inexpensive too. The bushing you referred to are just what you suspect...guide bushing to keep it centered in the outer tube. Probably held in place with steel stop rings. In the top of the cylinder there is probably a bleeder screw to bleed off air when you fire it back up. If so you might want to replace those as well as they get pretty gummed up. All are cheap parts.

Sounds like your right on top of this repair. Good Luck.