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.

 

[CliffordK]

My guess is that you've had a slow leak for quite some time.

Your hydraulic cylinder rods look mighty dirty. Of course we're only seeing an inch or so of the rods.

But the first thing I might do is clean the visible part of the rods (up to that rib of grease). Use a good degreaser?? If you can extend them a bit, all the better.

The rods should have a mirror chrome finish.

If they don't clean up, then you have bigger problems.

 

[oldnslo]

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 are not asking stupid questions. Yes typically the quick disconnects are close to the main directional control valve on the tractor. They allow removing the loader with minimal oil loss and no tools.

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?

Depends on where filter or hose is located in the circuit or system. The hoses connected to the cylinders should just drain oil in the lines between cylinder and main directional control valve. NOTE: Will state the obvious and make sure there is no weight induced pressure on the lines or learn from mistakes….

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.

To answer your question on operating in cold weather it should not cause cylinders to leak. I have operated equipment at -20 F and cylinders didn’t leak. Typical problem in cold weather is pump cavitation ( starving pump) since cold oil does not flow as well as warm oil does not get drawn into the pump.

 

[jyoutz]

What I do is remove the cylinder and take it to a hydraulic shop. It’s easier and you don’t have to source the correct seals and install them. But checking hydraulic pressure would be a good idea so you don’t damage the new seals.

 

[JimRB]

Adam Booth gives some great lessons in hydraulic cylinder operation, inspection and resealing. Here is just one video of many he has done.

 

[tankueray]

My guess is that you've had a slow leak for quite some time.

Your hydraulic cylinder rods look mighty dirty. Of course we're only seeing an inch or so of the rods.

But the first thing I might do is clean the visible part of the rods (up to that rib of grease).

You're probably right. Yeah, sorry, that grease is there because I love my battery powered grease gun and I mow a lot of dirt. I always rinse it off after the dirt party, but I've been meaning to get the pressure washer out since last summer. ('Round here, that's what we call a "protective layer"; we do not judge by the color of the tractor or pickup, because they're all brown.)

I always leave it down when parked, so hopefully they're okay.

NOTE: Will state the obvious and make sure there is no weight induced pressure on the lines or learn from mistakes….

I'll put the above advice under the "how not to drink fluid" category. Thank you.

But does that mean I need to suspend the FEL somehow or can I remove them as they are, compressed, with it sitting on the ground? Double action means either, right? I guess it only matters if I'm the one that has to remove the shaft, and extended won't fit in the back of my SUV, so compressed it is.

Here is just one video of many he has done.

Thanks, if mine turn out to look like that, I'm going to have to lock my toolbox and throw away the key.

• So, should I remove the hose at the quick connect (long and secured in multiple places) or at the cylinder (fittings look hard to put a wrench on and don't look like they swivel). Those front ones look like I can't get them off until I release the cylinder from the frame. And I don't think they terminate in quick connects after looking at the diagram.
• Is covering the loose hose connections with a baggie wrapped with electrical tape good enough to protect them from dirt?
• When things get reinstalled: Loctite, anti-seize, plumber's tape, or just clean?

 

[CliffordK]

The quick connects have a valve to stop the flow of oil. That will make working with them easier.

However, eventually a shop will want to strip down the cylinder. I probably wouldn't leave my hoses with a hydraulic shop.

 

[oldnslo]

A quick simple test to see if or how bad those lift cylinders are leaking would be to use the loader to lift the front of the tractor. Doing that puts the rod ends under pressure. With front tires off the ground you could walk around and look for yourself to see leak rate.

If decision is made to remove the cylinders then place the loader on the ground, turn engine off, move joystick in all directions to relieve any trapped pressure. That portion of the circuit is now depressurized and safe to work on.

 

[tankueray]

The quick connects have a valve to stop the flow of oil.

Yes! I learned that the other night, thank you! I'm used to air and water hoses, and only a few work like that, but the hydraulic ones have I guess a clamping mechanism that can limit the flow if not fully engaged, that's pretty cool. Funny story - I'm a huge fan of quick connects, and that's the only reason I figured out my weird PTO connection when I first got the tractor, it works opposite of how you'd expect and it's annoying. I have two impact drivers, one you pull on and one you push to engage/disengage. If I didn't have that other driver, think I'd still be trying to figure out that PTO.

I probably wouldn't leave my hoses with a hydraulic shop.

I think that is excellent advice.

A quick simple test to see if or how bad those lift cylinders are leaking would be to use the loader to lift the front of the tractor. Doing that puts the rod ends under pressure. With front tires off the ground you could walk around and look for yourself to see leak rate.

Oh, I saw it. Dad said it was leaking and I jumped off the tractor before shutting it down, with the forks still high enough above the ground for driving. It was streaming from both sides like a cow being milked. I'll bet it was a quart of fluid during the 60 seconds or so I watched them and after I shut off the tractor when the residual pressure was abating. That's the reason for the post title, it seemed so unlikely that they'd both start doing that at the exact same time, I thought there must be some explanation that every tractor or Bobcat owner knows that I don't.

If decision is made to remove the cylinders then place the loader on the ground, turn engine off, move joystick in all directions to relieve any trapped pressure. That portion of the circuit is now depressurized and safe to work on.

Yes, I'm going that route when the weather cooperates. I went to see my friend with the shop yesterday and he said to bring them in, we'd pull the shafts and get the parts at the hydraulic shop, and then repair them there. He's rebuilt the cylinders on his giant forklift more times than I can remember, and it's as old as me. He's also got a lathe and honing tools if we need to smooth any surfaces (the one that's my favorite is referred to as the "dingle ball").

He also said to lift it up a few feet and block it in case the shaft needs to be compressed to maneuver it out.

I have been so lucky that I have had men in my life that are willing to teach me rather than do it for me because it's faster or easier, and I thank you all for your patience and kindness as well. Y'all were wonderful in reducing my fear and anxiety just by explaining how things work. I'm not technically young anymore, but there are still young people out there that want to learn to "do"; please continue to share your wisdom and explain the "why" whenever the opportunity presents itself. I believe the world would be a much better place if we all got elbow-deep in grease or manure more often.

 

[aircommuter]

It’s correct that the cylinder is held together with that square wire you see protruding. You should pull on the wire and rotate the cap at the same time. Spray some penetrating lubricant in there first since moisture usually gets in those type. You can find online places to get cylinder kits by dimensions. When you go back together put some silicone or polyurethane sealant over the wire opening.

 

[Dennis Mohn]

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.

It would be good if you could extend the cylinders for a better view of the chrome rods. The pictures you have look fairly dry , where did the fluid appear to be from when you checked? Did you dry it any before taking the pictures, the cylinder ends look dry in the picture. ?. The dirt behind the pin boss could have worked its' way into the gland packing creating a leak. Both cylinders do not normally begin to leak suddenly and at the same time. That is the reason I mentioned the dirt and gland packing. If the bucket drifts down slowly as it sets it could be an indication of wear to the piston packing . the reason I asked for pictures for the cylinders to to see if there is any rust or "dings" on the rod which would also allow oil to escape past the gland packing. I have rebuilt many cylinders in the past and always check these things before beginning to dismantle the cylinder.