Both lift cylinders began spewing at the same time, what have I done?

[tankueray]

Howdy all,
I'm not sure what's going on. I have a Bobcat CT440 (Hydro) with the 9TL FEL. It has between 700-750 hours on it, I bought it used in June of 2020 with 604 hours on it. I have not used it since November, we've only had one week with a few days of hard freezing this year (in January). It was about 60 degrees yesterday when this happened.

Yesterday I started the tractor up, lifted the forks and rear brush hog in order to drive, and drove it about 100 feet - nothing is wrong yet. I picked up one of those plastic Keter storage sheds on a pallet (the box says it weighs 110lbs.), turned around, and moved it about 20 feet before setting it down. I'm not sure when in this operation it started, but both of my lift cylinders began spewing fluid. Once I parked the tractor, set down the forks, and shut it off, it was still leaking (I assume while the pressure went down). I pushed the joystick down after shutting it off, but didn't go side to side.

I did look in the manual and it said to warm it up for 5 minutes before lifting the front or rear, I'm pretty sure from start to shutdown wasn't even 10 minutes. Sorry.

Have the seals on my lift cylinders blown at exactly the same time? Bobcat wants $150 per kit, does anyone know of another option? Should I DIY or take it somewhere, I have the service manual and it doesn't cover the FEL at all, so I'll be not only doing this for the first time ever, but with no instructions.

FWIW - I'm a woman and a decent vehicle mechanic, but I know nothing of diesel engines or hydraulics (or tractors). I'm also concerned I might not have the physical strength to get the dumb things off the tractor, but I do have a friend with a shop that can help rebuild them. I appreciate any ideas or advice (like what to cover the hoses/holes with, how not to drink fluid, how to bleed the system after install, etc.).

Also, is it okay to add makeup fluid like Delvac or should I buy OEM?

The serial is AE3500XXX.
Thanks.

 

[tankueray]

I'm not sure if this will help, but here are photos of the cylinders.

 

[keony]

Odd coincidence there, might check the pressure relief valve might be stuck. Good luck.

 

[4570Man]

Cylinders are fairy easy to rebuild once you get them apart. Sometimes it’s easy to get them apart and sometimes it’s a real problem to get the pins out and get the end cap off. If that works like I think it does you have to rotate the end cap and that wire should push out the side. Once the wire is out the end cap would push out. Do you have a hydraulic shop locally? I’ve always disassembled the cylinder and taken it to a local shop to get matched up. In the absence of having that I’d probably just order the bobcat kit.

 

[oldnslo]

Tankueray
Where did the oil come out at on those cylinders? With the crimp type ends in those pictures they would appear to be single acting cylinders where they are powered to extend and gravity load retracts them. If my presumption is correct some pressure in those drain lines could have caused them both to leak at the same time.

Did the loader start to drop when you saw the leak?

 

[4570Man]

Tankueray
Where did the oil come out at on those cylinders? With the crimp type ends in those pictures they would appear to be single acting cylinders where they are powered to extend and gravity load retracts them. If my presumption is correct some pressure in those drain lines could have caused them both to leak at the same time.

Did the loader start to drop when you saw the leak?

I’m pretty sure that’s a crimp on hose sheath and the cylinder actually is double acting.

 

[tankueray]

Odd coincidence there, might check the pressure relief valve might be stuck. Good luck.

Where can I find that? Is it just for the FEL? There were no issues with the rest of the system while I was using it.

Cylinders are fairy easy to rebuild once you get them apart. Sometimes it’s easy to get them apart and sometimes it’s a real problem to get the pins out and get the end cap off. If that works like I think it does you have to rotate the end cap and that wire should push out the side. Once the wire is out the end cap would push out. Do you have a hydraulic shop locally? I’ve always disassembled the cylinder and taken it to a local shop to get matched up. In the absence of having that I’d probably just order the bobcat kit.

Yes, the YouTubes told me that it's a square lock ring. Strangely, this is primarily an oil and ag area, and I can only find two hydraulic shops in the directory, there are quite a few hose shops though.

Tankueray
Where did the oil come out at on those cylinders? With the crimp type ends in those pictures they would appear to be single acting cylinders where they are powered to extend and gravity load retracts them. If my presumption is correct some pressure in those drain lines could have caused them both to leak at the same time.

Did the loader start to drop when you saw the leak?

I think it was coming from the shaft seals. They're double acting, one hose connected to each end. The crimp is to hold on the cover (it looks like a sharkbite, and I hate those things). No, the loader and the rest of the hydro system worked fine, well except there was a bad jerk when I tilted the pallet. My dad was spotting me, and I didn't even know about it until he followed me to the parking spot and then decided to say something.

Since I bought it, it will ever so slowly drop overnight if I leave the bucket raised (the lift, don't know about the tilt). Honestly I figured that was normal if left under pressure, I've never met one that didn't; I always set both front and back on the ground before shutting it off.

What's weird is that the fluid was clear, I couldn't smell it, and it's not all over the tractor right now. We did have some light rain come through last night, but shouldn't there be some sign of a petroleum-based fluid on my paint or tires?

So the cold isn't a factor? Would it help if I told you that the tractor has always lived and worked in 80-120 degree temps? We have summer, hotter than hell, second summer, and maybe 5 nights below 30 degrees here. Except Snowmageddon a few years ago, which the tractor lived through. (I still don't know how to use the gel stuff, I just made sure it was full of diesel before it froze, and didn't drive it for a month after.) My friend is telling me that it's because it was cold and the leak will stop once we get back up into the 70's. I honestly don't remember ever using it when it's cold (below 75 for me), so maybe he's right?

 

[tankueray]

Okay, I found the relief valve in the manual. It looks like it's behind the left side foot step? Yes, I have one set of rear aux ports, thank God.

 

[oldnslo]

If lift cylinders there should no pressure on rod end while lifting so first thing I would check is to verify the quick disconnect for rod end is properly connected. Reason for this if partially connected you could get pressure intensification across the lift cylinders especially with no load on the bucket. That would explain both failing at same time.

I would expect to find oil residue where They leaked.

 

[tankueray]

If lift cylinders there should no pressure on rod end while lifting so first thing I would check is to verify the quick disconnect for rod end is properly connected. Reason for this if partially connected you could get pressure intensification across the lift cylinders especially with no load on the bucket. That would explain both failing at same time.

I would expect to find oil residue where They leaked.

Unfortunately, I don't know if they were leaking while lifting, because my dad is not good at paying attention to those things. I do know it was spraying in a stream while holding steady and after I dropped it down and shut it off.

Sorry, it's too dark and cold to go outside, there's a junction unit thing under the floor where all of the hoses, um, "initiate" from, I think it has quick connects on the back but I can't remember the front. It's either near to that main valve or on the opposite side I think. That's the thing you're talking about, right? (Am I asking a stupid question, are quick connects standard and that's exactly what you're talking about?) You can see from the pictures that there's not a quick connect at the actual rod ends, I remember looking for their ends and thinking they'd be hard to disconnect from wherever they go to, but unscrewing them from the cylinders didn't look too fun either. Thank you for the "why", I really appreciate that.

I promise I'm quite good at mechanics and machinery, but I'm in a foreign land here. I really wish there was a tractor class like driver's ed. I have to Google half the stuff I read here, that's why I've just been a lurker since I bought the tractor.

I'm still trying to understand opening up the system, like I can really take off a filter or a hose and all the fluid won't leak out? That sounds like one of my friends playing a trick on me. It would be much easier if there were a service manual for the loader, or any manual for it for that matter.