Green Tractor Talk banner

1 - 20 of 21 Posts

·
Registered
Joined
·
64 Posts
Discussion Starter #1

Hello all. Just took delivery of a new 1025r FILB with a 60mmm. Have about 10 hrs on it so far. Wow what a nice machine.
I have plenty of newbie questions but i'll limit this thread to hydraulics.
I've been taking off the loader and back hoe each day so I can mow our property and for practice etc.
It's been very hot here in NE PA the last few days. And both implements sat in the sun while I was mowing.
The loader and back hoe come off no problem, but both days, when I went to re connect each implement, the pressure in the hydraulic lines of the loader and back hoe had risen so high, that I just could not get the hoses to re connect!. So, both days I just let them sit until the sun when down and they cooled off, and then, no problem. Everything goes together fine.
When the pressure was low enough to re connect, you can take your finger and push on the male hose ends and they will release, squirting a bit of hydraulic fluid out. When I'm having trouble, no amount of force from me can get the line to release.
Has anyone else had this experience?
More of a symptom of the heat, than a defect it seams.
Just baffled. Thanks, George
 

·
Registered
Joined
·
149 Posts
I believe he is referring to putting the loader/backhoe back on after sitting in the sun.

Yes, seen it happen. Had same problem when we put plows outside. If we didn't connect the hoses on plow back onto each other, we needed to hit ball end of fitting with a hammer and have a towel over the coupling so we didn't get sprayed with hydro oil.

Can you put the loader or backhoe somewhere where sun isn't heating it up?
 

·
Super Moderator
Joined
·
2,267 Posts
Yes, what you described is quite common. When a disconnected hydraulic attachment has a temperature rise and is higher than when it was disconnected, it will experience a pressure increase inside of it. Since it's now no longer connected to the tractor, the pressure has no way to relieve, where if it were connected to the tractor the pressure would just relieve back into the system if you shut the tractor off and move the SCV stick to the 4 positions (raise, lower, dump, curl) for the FEL and/or mower. Shutting the tractor off and moving the backhoe's levers will relieve the pressure at the power beyond.

When you did what you described, having the attachments off and sitting in the sun, the pressure built inside them. You can relieve the pressure manually by covering the end of the male fitting with a rag to capture the spray of oil, and pushing the fitting against something hard and sturdy, like the frame of the tractor or attachment. Be careful not to inject it into your skin or eyes. That is dangerous and requires medical attention.
 

·
Registered
Joined
·
340 Posts
Normal problem with heat. Either try to reconnect when it is cooler in evening or morning or throw some towels or other protection over the connectors


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
1,312 Posts
You should be able to relieve the pressure even if it has heated up in the sun by operating the backhoe control levers and letting the pressure equalize. Only if all cylinders are fully extended should you run into a problem where there is nowhere for the excess pressure to go. This is assuming that when you disconnect the backhoe you are connecting the lines together so that the hydraulic circuit is complete.
 

·
Registered
Joined
·
2,159 Posts
When releasing pressures in hoses as others have said put rag over end of hose, I also put on gloves and safety glasses......
I have found safety glasses in both clear and tinted with readers in them, (for us older guys) so seems I wear them when ever I go out the door......
 

·
Premium Member
Joined
·
740 Posts
I've experienced a similar phenomenon after disconnecting the loader in the winter, and reconnecting in the spring. It is frustrating. I've thought about purchasing a Waite's Tool it can be seen in this thead where this image and contact came from the generosity of others. I have not pulled the trigger, yet...but will most likely regret it next spring when I fight it...again.


https://www.farmshow.com/a_article.php?aid=23028

George Waite
Waite's Tools
P.O. Box 66
Atwood, Colo. 80722
(ph 970 522-5696; [email protected])

 

Attachments

·
Premium Member
Joined
·
14,751 Posts
Wrap a rag around the end of the fitting, press the end hard against the frame or anything hard. It relieves the pressure on the fitting, wipe the fitting off with the rag. Works fine been doing this for the past 18 -20 yrs .
 

·
Registered
Joined
·
1,846 Posts
Serious question here.

If the fittings on the backhoe are connected to each other, as they should be, how can pressure build and not be eased by operating the levers to relieve said pressure, like you do when disconnecting it?
As someone else mentioned, even at high pressures, if the cylinders arent all the way extended, it will relieve it, will it not?

This obviously wont work with the loader, as those hoses cant be connected to one another, but should on the backhoe.

Years ago we would have this issue on some bobcat attachments from time to time, and while the loosen the fitting trick to bleed off pressure works, we didnt find it necessary on anything that had a working control valve past the connection.
 

·
Registered
Joined
·
12,341 Posts
Wrap a rag around the end of the fitting, press the end hard against the frame or anything hard. It relieves the pressure on the fitting, wipe the fitting off with the rag. Works fine been doing this for the past 18 -20 yrs .

remind me not to try and shake ur hand the next time we meet:lol: even yrs ago when my hoses did that sitting in the garage-why-IDK-:unknown:i would say i just did not have all the pressure off the bucket, before disconnecting the hoses?:dunno:

i bought a set of them Wait's pliers then, used them one time and haven't had to since then. they work nice--since then have seen what others have invented for way more pennies less than the fancy dancy pliers :laugh: but as my wife says-I own a set-just had to have them-famous last words of hers:mocking:
 

·
Registered
Joined
·
1,312 Posts
Serious question here.

If the fittings on the backhoe are connected to each other, as they should be, how can pressure build and not be eased by operating the levers to relieve said pressure, like you do when disconnecting it?
As someone else mentioned, even at high pressures, if the cylinders arent all the way extended, it will relieve it, will it not?
Yes, it will relieve the pressure - even if you live in the South. :thumbup1gif:

You may need to operate multiple levers at the same time but unless all cylinders are extended there will be a place for the hydraulic fluid under pressure to flow to.

In case someone doesn't know why - there is less volume in the rod side of the cylinder than the other side, because the rod takes up space. When a cylinder is extended a greater volume of fluid goes into the cylinder than comes out, thusly if there is pressure in the system you can create more space by allowing a cylinder to extend - which the fluid under pressure will go into.

Now if your outriggers are on the ground, the bucket fully curled, the dipper tucked all the way in and the swing pinned - then you may not have an unloaded place for the excess pressure to go. In that situation you might have to relieve the pressure the hard way, or remove the swing pin if you can do it safely. It is a good reason to store with the outriggers all the way up - with them up there will always be a place to bleed excess pressure to - and it protects the chrome plating of the cylinders.
 

·
Registered
Joined
·
2,942 Posts
Serious question here.

If the fittings on the backhoe are connected to each other, as they should be, how can pressure build and not be eased by operating the levers to relieve said pressure, like you do when disconnecting it?
As someone else mentioned, even at high pressures, if the cylinders arent all the way extended, it will relieve it, will it not?

This obviously wont work with the loader, as those hoses cant be connected to one another, but should on the backhoe.

Years ago we would have this issue on some bobcat attachments from time to time, and while the loosen the fitting trick to bleed off pressure works, we didnt find it necessary on anything that had a working control valve past the connection.
Whether the hoses are connected together or not, fluid is still trapped on both sides of the hydraulic pistons. If the valves are cycled then possibly the small differences in pressures between the rod side of the cylinders and the piston side may equalize but will be still greater than the atmospheric absolute pressure.

I have used the rag over the fitting against a hard object often but the pliers tools look pretty sweet.
 

·
Registered
Joined
·
1,396 Posts

Hello all. Just took delivery of a new 1025r FILB with a 60mmm. Have about 10 hrs on it so far. Wow what a nice machine.
I have plenty of newbie questions but i'll limit this thread to hydraulics.
I've been taking off the loader and back hoe each day so I can mow our property and for practice etc.
It's been very hot here in NE PA the last few days. And both implements sat in the sun while I was mowing.
The loader and back hoe come off no problem, but both days, when I went to re connect each implement, the pressure in the hydraulic lines of the loader and back hoe had risen so high, that I just could not get the hoses to re connect!. So, both days I just let them sit until the sun when down and they cooled off, and then, no problem. Everything goes together fine.
When the pressure was low enough to re connect, you can take your finger and push on the male hose ends and they will release, squirting a bit of hydraulic fluid out. When I'm having trouble, no amount of force from me can get the line to release.
Has anyone else had this experience?
More of a symptom of the heat, than a defect it seams.
Just baffled. Thanks, George
congratulations on your new toy. I've got a 1025r FILB on order, thanks for posting the issue as I will likely encounter the same problem. In my case I will never do any mowing except with my old 1975 Brush Hog which even still has the southern flag on the side! Brush hog small IMG_20180621_202535765_TOP.jpg
 

·
Registered
Joined
·
1,312 Posts
...If the valves are cycled then possibly the small differences in pressures between the rod side of the cylinders and the piston side may equalize but will be still greater than the atmospheric absolute pressure.
It won't be higher than atmospheric pressure*. The reason is that when a cylinder is extended the total volume of the system increases. With the valves opened it provides an unrestricted path for the pressure to equalize. Only if there is some resistance to a cylinder extending will the pressure rise above ambient.

It goes like this: the sun heats up the fluid, it want's to expand but has nowhere to go because the valves are shut blocking off any pathways. There is more force on the backside of the cylinders than the rod side so the fluid is trying to extend the cylinders but cannot because there is no path for the fluid on the rod side to escape. The result is that the pressure in the lines increases.

When you cycle the valves you open a pathway for the fluid to escape from the rod side of the cylinder and the cylinder extends which increases the total volume of the system and the fluid equalizes on all sides. If at least one cylinder is allowed to extend freely it will "use up" all the excess pressure. Additionally, if you were to manually extend a cylinder - such as pushing down one of the outriggers - you would lower the pressure in the system to below ambient - the appropriate valves would need to be open when doing so.

*It is a closed system so I believe that it would be slightly higher than atmospheric pressure due to the resistance of seals and what-not, but a small enough difference that it would have no effect on the ability to make a connection.

A thought experiment, take a hydraulic cylinder and connect both ports with a hydraulic line. No valves, just a completely open circuit. The cylinder is full of hydraulic fluid and it is extended half way. Now heat it up.

What happens? Does the the cylinder extend or does it stay still?
 

·
Registered
Joined
·
1,396 Posts
It won't be higher than atmospheric pressure*. The reason is that when a cylinder is extended the total volume of the system increases. With the valves opened it provides an unrestricted path for the pressure to equalize. Only if there is some resistance to a cylinder extending will the pressure rise above ambient.

It goes like this: the sun heats up the fluid, it want's to expand but has nowhere to go because the valves are shut blocking off any pathways. There is more force on the backside of the cylinders than the rod side so the fluid is trying to extend the cylinders but cannot because there is no path for the fluid on the rod side to escape. The result is that the pressure in the lines increases.

When you cycle the valves you open a pathway for the fluid to escape from the rod side of the cylinder and the cylinder extends which increases the total volume of the system and the fluid equalizes on all sides. If at least one cylinder is allowed to extend freely it will "use up" all the excess pressure. Additionally, if you were to manually extend a cylinder - such as pushing down one of the outriggers - you would lower the pressure in the system to below ambient - the appropriate valves would need to be open when doing so.

*It is a closed system so I believe that it would be slightly higher than atmospheric pressure due to the resistance of seals and what-not, but a small enough difference that it would have no effect on the ability to make a connection.

A thought experiment, take a hydraulic cylinder and connect both ports with a hydraulic line. No valves, just a completely open circuit. The cylinder is full of hydraulic fluid and it is extended half way. Now heat it up.

What happens? Does the the cylinder extend or does it stay still?
So your implying that JD hasn't installed a pressure relief valve in the system to prevent catastrophic failure under this kind of condition? I would think the pump would have one that vents back to the reservoir,
 

·
Registered
Joined
·
1,312 Posts
So your implying that JD hasn't installed a pressure relief valve in the system to prevent catastrophic failure under this kind of condition? I would think the pump would have one that vents back to the reservoir,
We're talking about a disconnected backhoe here...
 
1 - 20 of 21 Posts
Top