Hydraulic Cylinder Replacement

BenTh · Jun 17, 2005

Hello,

Well I've played around a bit with the PT-1418 that you might have heard about in another thread. Mowed about 5 acres with a Trailmower. Then I got around to moving some dirt. Oops!

The hydraulic cylinder that drives the bucket tilt failed. Best that I can reconstruct the failure is as follows. The actuator looks like it had become over extended (i.e. that is in the direction of the bucket tilted full up). I then lowered the bucket and POP! the piston arm was not longer parallel to the cylinder and oil was gushing out around it.

There is an internal nut in the cylinder which appears to attach the piston rod to the internal piston thing which was missing, hence I beleive it had become overextended. Lowering the bucket then caused the pivot arm to seat against a cross brace in the two large weight bearing arms (since the cylinder was overextended). This then appears to have caused the cylinder plunger to be stressed and caused it to pop.

So, I would appreciate it if anyone has any experience or knowledge re: sources for replacement cyclinders for the PT. I did some looking around but didn't find anything with the 'eye socket' ends that they used. But I'm probably just looking in the wrong places.

I'm going to check with PT next week, but I'd also like to see what other options I might have, if any.

Thanks,

Ben

Bob999 · Jun 18, 2005

My understanding is that PT manufacturers the hydraulic cylinders they use. I don't know if that has always been true but it is my understanding for current models.

I suspect that PT will be your best source of repair parts or a replacement.

toy · Jun 18, 2005

If it is not messed up too bad you might be able to get it rebuilt at a local hydroulic shop.

BenTh · Jun 18, 2005

( If it is not messed up too bad you might be able to get it rebuilt at a local hydroulic shop. )

When I first started looking at it, I had hoped that it could be rebuild. However, I'm not sure it can, or it's worth it. The actuator piston thing is pretty well bent. The bend is right where the diameter reduces down to accomodate the stuff that goes on the end of it. So that'd have to be replaced.

Then, I'm not sure about the front of the cylinder. With the bent rod coming out of it, it appears that the hole has become slightly elliptical. If this end is replaced as well, I suppose it could be done.

That being said, I'll look into it. Perhaps it's not as bad as it appears to me.

Charlie_Iliff · Jun 18, 2005

Ben:
There are a lot of sources for hydraulic components, including local shops and tractor supply places like Tractor Supply Corp. You might get lucky at a TSC and have your cylinder match one for a 3 point tilt or other application.
Over the years, I have gotten good service from Bailey, as well as advice on the phone. If you measure the piston diameter, the open and closed pin to pin lengths and the pin sizes, I'll bet they can match it.
. Bailey

J_J · Jun 18, 2005

I rebuilt the lifting cylinders on my 1445 last year. I ordered the rebuild kits from PT, and replaced all soft parts. The only similar cylinders that I could find were the top link cylinders for tractors. Baileynet.com will build any kind of cylinder you desire. If you get the cyl from PT, they run about $105.00 for the lift cyl for my Pt-1445.

Sedgewood · Jun 18, 2005

If you get the cyl from PT, they run about $105.00 for the lift cyl for my Pt-1445. 

That doesn't compare unfavorably to the cost of a $12.00 PT rebuild kit once you factor in their $50.00 minimum order. You gotta buy four to get one! /forums/images/graemlins/tongue.gif

Sedgewood

J_J · Jun 18, 2005

I wrote my reply before I had read all the post. I think he damaged his cylinder beyond repair, and the nut that hold the inside guts to the rod, was missing. What I think happened, was that the tilt cylinder was already extended, or bottomed out, and when the lift cylinders were extended or brought to full down, it made the tilt cyl go past manufacture design. A loose nut on the inside of the cyl might have helped this to happen. On my 1445, I have a flat spot on the tubes that are in between the lift arms. I can see how this could happen.

davesisk · Jun 18, 2005

Hey Ben:

I'm having a hard time visualizing this. Can you post some pics?

One poster said that these odd cylinder links resemble 3-pt toplink cylinders, which sounds like an awefully good guess. The ends of the older 3-pin connection deal are weld-on cat 0 3-pt lower links, if I'm not mistaken, so that wouldn't surprise me at all if these were 3-pt cylinders.

Sounds like the best choice based on some of the posts is just to get a replacement from Power-trac. Since a loose nut on the inside of a cylinder isn't something that you're likely to notice until it's too late, I'd definitely suggest checking the lift arm cylinders and steering cylinders just to make sure they appear to be tight.

Locally, Gregory Poole Equipment in Raleigh has a great hydraulics shop...they could've rebuilt the wheel motor I replaced had it been rebuildable (it wasn't), and they had the best price (even considering mail order sources) on a new wheel motor. Definitely give them a call even if you don't think the cylinder is rebuildable...they may be able to replace the rod and piston pretty cheap if the cylinder sheath isn't damaged. If they can't rebuild it, they may be able to get the same cylinder for a better price than Power-trac. Just a thought...

HTH,
Dave

BenTh · Jun 19, 2005

( What I think happened, was that the tilt cylinder was already extended, or bottomed out, and when the lift cylinders were extended or brought to full down, it made the tilt cyl go past manufacture design. )

From what I could reconstruct, this is close to what happened. However, I believe that the cylinder was damaged before the lift cylinders were brought down. In fact, the lift cylinders were about half to three quarters extended when the tilt cylinder broke.

I'll post some pictures tommorow of the failed cylinder (I just got my camera back tonight.)

Anyway, best as I can reconstruct, with the lift arms almost fully extended, the tilt cylinder jammed in an overextended position. I say 'overextended' since there is evidence that the tilt pivot arm seated against the upper lift arm crossbrace, which I assume would not happen if the tilt arm were not overextended.

As the lift arms were lowered, the tilt pivot arm seated against the crossbrace, putting pressure on the tilt cyclinder. Since the tilt cylinder was fully extended and probably overextended and jammed, the cylinder bent like an elbow with the junction between the piston rod and the cylinder being the elbow joint. Said bending, not being in the nature of this type of hydraulic cylinder, caused it to start squirting oil on my lawn!

I've checked the tilt pivot arm and it turns freely without a hint of jamming, so it's unlikely that it caused the failure.

I believe that the root cause of the failure was actually the tilt cylinder. It would seem to me that it first failed, causing it to overextend and possibly jam. The overextension pushed the tilt pivot arm until it seated against the crossbrace ( I am assuming that the mechanical design is such that this would not happen if the tilt cylinder extension were to remain in its normal range.) Then with the pivot arm seated against the crossbrace, when the lift arms were lowered, the pivot arm could no longer pivot, putting all the pressure on the tilt cylinder, and pop!

Anyway, as JJ said, the cylinder is probably beyond repair. The piston arm is bent (look for pictures tommorow). The nut or whatever that was threaded onto the piston arm is no longer threaded onto it. I don't know if this was the cause of the failure or because of it.

I feel fortunate that it was the cylinder that went rather than something else. The lift arms look ok. There is a small twist to one of the arms on the tilt pivot, but it's small and I don't think it will be a problem. Crossing my fingers that I don't have to bend it back. /forums/images/graemlins/frown.gif