Need education/advice on rebuilding telescopic main cylinder on Cat TC30 forklift.

[Kawgomoo]

I have a little cat tc30 fork lift. the main cylinder is drooling out the bottom and the forks drift down.

I cannot seem to locate any information on how to properly disassemble and reassemble the cylinder, much less service specs or anything like that.

I feel i have average mechanical ability, but no forklift experience at all.

The repair manual on ebay is 200 dollars, which puts it well out of my reach.

 

[joestewart]

Remove cylinder from machine. Disassemble cylinder paying scrupulous attention to the proper placement and orientation of all the components. Install new o-rings and seals and lube generously. Torque the piston nut to specification (note: this may be hundreds or even greater than a thousand foot pounds). Slide gland onto rod. Slide rod with piston into cylinder. Torque gland nut. You are done!

It might pay to leave the base of cylinder attached to machine so that you can apply torqe to the gland nut while the rest of the cylinder is fixed in position.

The repair manual will probably not tell you how to rebuild the cylinders. The Lull manual was $169 and it gives no detail on how to rebuild the cylinders.

My Lull manual gives some torque specs for gland nuts depending on nut size. I can email this to you.

I had never rebuilt a cylinder before I serviced the four cylinders on my Lull forklift. It is certainly within your capability.

There is a ton of youtube videos on how to rebuild cylinders.

If you run into trouble during the rebuild, go to the local hydraulic shop to seek advice (as I did on multiple occasions - it helps to make a token purchase of o-rings and seals while trying to get the free advice)

Keep all dirt and dust out of your cylinder during the process.

Send my your email address and I'll email you this table out of the Lull manual.

 

[Kawgomoo]

Well, if this was a single ram cylinder i wouldnt be so hesitant. But this thing is just weird. Its a telescopic cylinder, 2 stages i believe. But it is possible that its a 3 stage.

It seems the "body" of the cylinder is in the middle, and there appear to be ram rods that extend from both the top, and bottom, of the cylinder body.

I could be crazy. I will take a closer look today and snap some pics.

Any input on who to call for parts? I tried Baum Hydraulics, but they didnt have a listing for my machine. He said tear it down and call back they might be able to match it up. {that slightly worries me**

 

[joestewart]

Sounds more complicated than I thought.

But even so, I think it could be done.

Tear the cylinder down and when it comes to needing parts, bring the torn down cylinder to your local hydralic rebuild shop. They will match up all the o-rings and seals and should not cost more than, say $40 for all these parts. You may have to leave the cylinder there for a couple of hours so they can match every thing up.

I went through the two boom lift cylinders on a 1974 Bantam excavator. Called the company that took over Bantam (forgot name) and asked for rebuild kit for cylinders. They quoted me $149 each (I needed two) and I would have to wait two months (not sure of the reason for the wait - I thought it was to give them a chance to "make" the seals). Well, I brought the old o-rings, wear pads, seals and just the gland (the cylinder was too huge to haul down to the shop) down to the local hydraulic shop. It took them about four hours, but they matched everything up and it cost under $40 total. I did not have to purchase anything from Bantam. Got some great advice from the techs there and went home and assembled cylinders. That was three years ago and excavator is still being used today with no leaks from those cylinders. Someone told me that the hydraulic shop would charge $700 each to go through those huge cylinders.

Anyway, I think you can do it. Anxiously awaiting photos. From the looks of the cylinder, what kind of wrench is going to be necessary to get the gland off?

 

[BillG]

The "body" that you refer to is free lift portion of the cylinder. This part raises the carriage (forks) through the first level without raising the inner rail of the mast, thus free lift. After that it depends on whether this is a duplex or triplex mast (how many rails including the outside one). A duplex will have a stage that comes out the bottom and so on. A Cat lift truck dealer can order your parts or may have them on the shelf. This is a pretty common model, have your serial number ready. Also they may ask for the mast deck number which is stamped in the mast usually on a flat surface but they can be difficult to locate depending on how many coats of paint cover it.

 

[Kawgomoo]

Are there any tricks or precautions to note when taking this thing apart? aside from generally paying attention to what came from where.

 

[BillG]

Without knowing exactly which mast that you have it is difficult at best to be specific. Generally speaking, make sure that when you get ready to remove the cylinder that you properly support the sliding sections of the mast. When removing the carriage (what the forks are connected to) that you don't get your fingers in the wrong places and when disconnecting the chains make sure that you tie them so they don't suddenly roll off the sheeves and hit you in sensitive places. If you have sideshift and it uses a hose take up reel (outside the mast channels), the reel is spring loaded and can ruin your day if the hoses get away from you.

 

[Kawgomoo]

Alright, well i got the cylinder out. It wasnt much to undo, but man. It was alot of work. That thing is freaking heavy!!

Basically i just released the upper and lower pin, took off 2 of the chains and jacked part of the mast up to free the cylinder. I had a little toe jack i made for lifting lathes and stuff off the ground to get rollers under them. Worked perfect for lifting the section of the mast.

But now that i have it out and sitting on the bench. Im confused, again.

You hit it on the head about the body sliding up and down a fixed shaft, and that shaft has 2 shafts that telescope downward from it.

Where do i start disassembling this thing? Do i remove the collar that needs a pin spanner? that collar is what holds the packing in the "body" there also seems to be another collar on the middle rod that holds packing between it and the last stages rod.

That make any sense?

Basically...do i work big to little or little to big?

 

[Kawgomoo]

Alright, got it all apart. That was a small nightmare. Turned a set of oil filter pliers into a pin spanner. Worked well enough.

Everything came apart smooth, pretty obvious what goes where and how it all comes apart once you dive in. Alot of trepidation on my part. I have zero experience with this sort of thing, and its a personal machine that ive worked my entire life to be able to afford. And it still aint much.

My only question now, is on this 2nd stage cylinder does the piece in the middle, above the oil holes, come off? If so....How? I have attached a pic and circled the part in question. It seems it will turn on the shaft, but doesnt want to slide in either direction.

 

[BillG]

No need to remove it, the poly seal has to go over the piston anyway, and it's not meant to be removed. Make sure you install the seals with the lip in the correct direction (towards pressure). It helps to heat the poly seals before installation to get them a little more limber. Heating them in hot water works best (boiling oil can get real ugly), and don't get in to much of a hurry that you cut the seal. Work steady with blunt tools when working them around the piston. Use plenty of vaseline or assembly lube when assembling.

 

[Kawgomoo]

I have a little plastic seal stretcher onner thing left over from fixing my buddies bmw. I think a little hot water and i should be good to go.

Hurry is not in my nature. Everytime i try and move alittle faster i screw something up and set myself back 2 days. Slow and steady is my only speed. Not even all that steady at times.

Thanks for the heads up on that piston. I was really worried i would need to remove it {because i cant**.

Looks like this should go back together pretty easy.

There is one high spot {digger** on the piston shaft. I would like to dress it down. Any recomendation on what Arkansas stone to use. Is white fine enough or do i need a harder, finer cutting stone?

 

[BillG]

Probably harder, hard chrome is is too much for a file or soft stone. You won't know until you try it, how deep, long and wide. There are some commercial fillers that I have used in deep grooves. I have also brazed in a few bad ones and then stoned them off.

 

[Kawgomoo]

Its a little pinger, about the size of a pennies edge. But it has a little raised lip around it, i just dont want it to cut any seals on there way on.

 

[BillG]

Just clean up the lip so a fingernail won't catch it.

 

[lodgey]

Nice discussion. I always wonder about the such information. Disassembly is something that makes me worry about my machines and equipment. This forum is rather useful as I will be able to provide some information whenever it required. I will also try this too.