My FEL is bleeding down

   / My FEL is bleeding down #1  

StuartDK45SE

Silver Member
Joined
Dec 28, 2014
Messages
206
Location
Angleton, Texas
Tractor
Kioti DK45SE
2013 DK45SE bought new in 2014, only 64 hours.

I thought I noticed the other day that my FEL wasn't where I left it several hours earlier. Today I took a measurement and came back three hours later and it had bled down 3 inches in that time. What is acceptable? I would assume as new as it is for it not to bleed down at all.
 
   / My FEL is bleeding down #2  
That is pretty normal. The control valve does not have O rings or other seals other than very close tolerance between the valve body and the spindles.
Some bypass will occur under load.
 
   / My FEL is bleeding down #4  
Yep, 3 inches in 3 hours or an inch an hour is well within normal. Some are tighter than others, and might bleed a little less than that, but they all bleed down some.
 
   / My FEL is bleeding down #5  
Just about all hyd will leak down, some will hold better that others.

Worn seals will allow the cyl to leak down .

Worn spools in the hyd valve could leak down.

You tractor dealer service dept will have the leak down tolerance for your machine.

Sometimes it is how much you can tolerate.

Is it a safety concern
 
   / My FEL is bleeding down #6  
As others mention, valve bodies have no seals. IT is a tight metal on metal tolerance and not 100%.

3" in 3hrs is likely acceptable. But call the dealer and ask.

Worn out seals in a cylinder will cause the loader to be weaker, but will NOT cause the loader to leak down UNLESS there is an external leak somewhere.
 
   / My FEL is bleeding down #7  
Can it be true that thousands are rebuilding their cyl to fix a leak down when it is the valve causing all the problem.

It just seems to me that a load placed on a leaking cyl will leak down. That load being the bucket and lift arms.

It does seem strange that people that rebuild their cyl don't have the leak down after rebuilding.

Few people on TBN have said that by replacing the valve that the leak down was stopped.

Same with the 3pt leak down. Few people are replacing their 3pt valves.

They all seem to do the cyl. Why is that.

Just saying.
 
   / My FEL is bleeding down #8  
Those rebuilding the cylinders may well be solving a problem with leak down. Especially if the leak down occurs during operations. Cylinders do have O rings on there pistons and do wear out and leak by.
However, if you raise the FEL and shut the engine off some slow leak down will occur due to the spools allowing fluid to bypass. The spools are letting fluid from all three cylinders to bleed off pressure and the FEL lowers. If one cylinder has bad O rings the other cylinder will not be leaking down and support the bucket and arms. Rebuilding the worn cylinder will correct that problem.
 
   / My FEL is bleeding down #9  
Even though the valve spools will leak some due to metal to metal tolerances, There is a leak down rate in drops per min for that situation for the dealer to replace the valve.

Now, let me ask you whether you would replace a $50 set of cyl seals or a $300 valve.

Now consider this, if a raised bucket and lift arms is putting down pressure on the piston in a very good cyl, that would therefore accelerate the valve leak down rate, correct.

So what pressure do the dealers use to establish the leak down rate, a static situation or a dynamic situation.

You might not even notice the leak down when using the cyl, except if you can't make the cyl go into relief, then you know something is wrong.

So now, add a cyl with worn out cyl seals, raise the loader and add a shutoff valve in the base end of the cyl, do you think the lift arms and bucket will descend a certain amount until the pressure is equalized.

In a static environment with no pressure and worn seals, the piston probably will not move in a cyl.

I am so confused, but not really.
 
   / My FEL is bleeding down #10  
It just seems to me that a load placed on a leaking cyl will leak down. That load being the bucket and lift arms.


Just saying.

Only if the cylinder is leaking externally.

It does seem strange that people that rebuild their cyl don't have the leak down after rebuilding.



Just saying.

If there was an external leak past the gland nut, then yes a rebuild would fix this. Or possibly one more theory I will discuss at the end of this post.

Same with the 3pt leak down. Few people are replacing their 3pt valves.

A 3PH is totally different. The "rod" side of the cylinder is open to the case (tank). So a leak past the piston goes straight to the tank. On a loader, the leak past the piston would HAVE to go through the valve (which is closed) to get back to tank. So, if the valve is TIGHT and NOT leaking by, there is no leak down.


Now that theory I mentioned. It IS possible for the valve spool to only be leaking by on the rod side port. In that case, if piston seals are shot, then fluid can bypass the piston, and then bypass the valve spool and you have leak down. In this case, Rebuilding the seals will stop leak down. But so would a valve replacement.

I know this has been debated on here FAR too many times. It is simple hydraulics. With a properly functioning valve, any fluid that wants to bypass the piston seals STILL has no where to go and should not leak down.

You can completely remove the seals, raise the loader, and unhook the quick connects and it will stay up all day long.
 
 
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