I have an OLD Towmotor forklift with a 4000lb capacity. It's leaking hydraulic fluid from the top of the mast cylinder. I managed to tighten up the packing nut some, but it needs to be re-packed. My question is this: Can I use corrugated ribbon valve stem packing on top of the remains of the existing packing? Or would that make things worse? I saw an article about installing new packing rings without disassembling the cylinder (just cut them and stagger the rings), but finding the right rings for this beast could be a problem. Believe it's left-over from WWII. I'll post the ID plate info later - just need to know about the packing issue for now. Thanx!
cutting and staggering the packing is acceptable in this instance, as I believe the lift cylinder is a single acting cylinder and the top hose is a vent line back to tank and under no pressure .check to see if the hose is kinked or blocked between cylinder and tank any hydraulic repair shop should be able to supply chevron V style packing's in most sizes.(I hope my memory has not failed me on this reply as it has been some time since I have worked on one) Mark
Toadmotor was bought out and became CAT lift truck, but I agree it's most likely just chevron packing that was quite common on the older lift trucks of all brands. I think it was Hyster that used decimal sizes rather than fractional just to mess everybody up. The kits used to come with a stack of already split rings including a flat top and bottom, just pick all the old ones out and lay the new ones in, staggering the joints. Good luck!
Should be no problem finding a hydraulic repair shop in Orange County CA. Just need to measure the ram OD and the ID of the cylinder head then remove the old packings and estimate how tall a stack there was in there when new. To get the old ones out try using say a #6 or #8 sheet metal screw to screw into them one at a time and pull them out. Or go fancy and buy something like these: http://www.gasket-tools.com/packing-tools-hooks.asp The shop you buy the seals from may even have those tools on the shelf.
Thanks for the responses everyone! I'm sure I can find the proper seals somewhere.....Now what I need is a hook spanner wrench to tighten the packing nut with....Maybe one of those "hinged" adjustable spanners. The nut's about 4" - 4.5". Been using a block of wood and a hammer (not very accurate). Think I can rent one somewhere? Seems like they cost about $80 or more to buy. A lot to spend for a (probably) one-time use tool. Thanks again!
How good are you with a torch? Just make a template out of some cardboard and trim till it fits the packing nut real nice then take a plate of say 3/8 thick steel and transfer the pattern to it and cut out with a torch. Leave a little meat to let you grind and file till it fits just nice leave a short arm on it that you can slip a piece of 1 1/2 DOM tubing over and you are good to go! Now if you are real lucky and know someone with access to a water jet or plasma torch table you can save a bunch of time with the grinder and files! Or do a search on Ebay: http://www.ebay.com/itm/VTG-WILLIAMS-HOOK-SPANNER-WRENCH-No-474A-4-1-2-TO-6-1-4-ADJUSTABLE-USA-/262318526148?hash=item3d13670ec4:g:MrgAAOSwP~tW2NQP or: http://www.ebay.com/itm/Pro-America-Kal-Tool-Adjustable-Hook-Spanner-Wrench-2-to-4-3-4in-MADE-IN-USA-/131372503719?hash=item1e966952a7:g:rPMAAOSw7ThUhMI9
Wish I had a torch - woulda made a spanner a while back. But, I followed your links and found that they're not all that expensive after all. Don't know where I got $80 from. Guess I'll just buy one. Found a couple of hydraulic shops in the area, so I'll be measuring the old parts. I know I can get the dimension of the ram, since it's right there.....measuring the internal bore of the cylinder could be a little trickier. I do have an inside caliper - question is if it's long enough to reach down in there once I get the packing nut off and the old seals out....We'll see. Thanks for your help. I'll let you know what happens.
if it is 1 way cylinder your seals on the bottom of the rod may be worn out causing oil to seep a round and push out the top.
I guess it is a one-way....It's the main mast. Power to lift, gravity to lower. Am I gonna have to dis-assemble this whole thing, or can I put new seals in from the top (removing the old seals)?
Should be a displacement cylinder, only the rod seals at the top. Let's hope anyway.
Did some more cleaning and was curious about the vent hose at the top of the mast cylinder - followed it down to the main hydraulic oil tank. So, it's an overflow/drain too......Anyway, the hose and the elbows were clogged solid with goo. Cleaned 'em out and reassembled. It still needs new top end seals, but the constant leakage has been reduced quite a bit. Onward and upward.