ARK500 FEL leaks down slowly

[HyperPete 641]

My FEL leaks down somewhat slowly when raised.  There is a slight amount of oil on the pistons, but not nearly enough to cause drips.

Could low oil cause this, or air in the system, or am I looking at seal cleaning / replacement?

Does anyone know where/how to check the level, and/or how to bleed?

To clean, will a seal saver for motorcycle forks work?

I presume it uses standard hydraulic oil, such as for aircraft hydraulics or air compressors.

Thank you!

[HyperPete 641]

I found this thread  but it does not go into testing or bleeding.  It's also for an ARK550 which I'm guessing is very similar to the ARK500.

 

[wallfish 17,597]

Most used motor oil

The reservoir drain and fill is on the upright. 

To bleed a hydraulic system just use it and cycle through all the cylinders multiple times. The air is released in the reservoir. But you need to keep checking the level as the air is released it's replaced with oil. If it feels "Spoungy" that is air in the system compressing. Keep cycling through to get it all out.

 

The leak down is most likely in the valve. Oil leaking past those seals inside. It just flows through the return lines and into the reservoir. Could also be the cylinder seals.

Raise the bucket, shut off the engine and disconnect that return line at the reservoir and catch any oil in a container. if oils drips it's seals somewhere. If it doesn't it's a leak somewhere

 

Search the files for a manual

[lynnmor 7,623]

1 hour ago, wallfish said:

The leak down is most likely in the valve.

Pay attention to this short sentence, for a cylinder to move an unequal amount of oil needs to move out of one side while oil moves into the opposite side.  Because one side has the rod taking up much of the space even a cylinder with bad seals won’t move much unless there is an additional problem and often that is the valves.

[HyperPete 641]

Thank you for the replies.  I considered the seals because if the oil seeped past them, it seemed to make sense that the volume in the pressure side would be reduced, allowing it to drop.

I understand now that this is not necessarily the case, and I will test by disconnecting the return line, as @wallfish suggested. 

This may take me a while to do, as summer chores and maintenance around the home & yard take precedence. 

Happy wife, happy life!

Edited July 6, 2023 by Pete D

[wallfish 17,597]

4 hours ago, Pete D said:

Thank you for the replies.  I considered the seals because if the oil seeped past them, it seemed to make sense that the volume in the pressure side would be reduced, allowing it to drop.

I understand now that this is not necessarily the case, and I will test by disconnecting the return line, as @wallfish suggested. 

This may take me a while to do, as summer chores and maintenance around the home & yard take precedence. 

Happy wife, happy life!

When I had mine it would leak down but not enough to worry about. I had no need for holding stuff up with it overnight so it wasn't really an issue. For winter storage the bucket was rested raised and up against a wall for space reasons. If it's not a bother to you then maybe not bother with it. VERY common for older hydraulic systems to leak down slow. Leaking down fast, that's definitely a problem that should be fixed. 

[gwest_ca-(File Mod) 11,281]

https://www.wheelhorseforum.com/search/?q=ark&quick=1&type=downloads_file

[HyperPete 641]

5 hours ago, wallfish said:

When I had mine it would leak down but not enough to worry about. I had no need for holding stuff up with it overnight so it wasn't really an issue. For winter storage the bucket was rested raised and up against a wall for space reasons. If it's not a bother to you then maybe not bother with it. VERY common for older hydraulic systems to leak down slow. Leaking down fast, that's definitely a problem that should be fixed. 

Slow is relative.  It does not slam down, but it drops noticeably when I drive 500 - 1000 feet (6" to a foot).

I guess, in retrospect, that's somewhat fast.  Manageable for the time being, however.

 

@gwest_ca - thank you.  I searched for FEL and got similar results.  The 1980 version shows an exploded view of the valve block, but I won't know if the o-ring sizes will be accurate until I tear into it.

[HyperPete 641]

Google found this, which I may go by.  New spool block could be an option if necessary.

 

[HyperPete 641]

Update: FEL is Ark 508QM

 

(Found my tractor, formerly for sale here.)

 

[HyperPete 641]

Thread revived from the dead.

I have read 4 manuals and multiple threads.

I cannot, for the life of me, find any information concerning changing the oil.  There is plenty of info concerning total oil capacity, what kind of oil, where to fill, how to bleed, and where to check fill level.

Can anyone tell me how to completely DRAIN it in order to fill it with fresh oil?  Do I have to disconnect hoses and do several fills & drains to get all of the old oil out?

 

I have many projects in various states of completion, but this just became a priority because the FEL won't lift a rototiller.  Probably just low on oil, but that's a good reason to change it for the 1st time since I have owned it.

 

Thank you!

[953 nut 58,332]

You won't get 100% of the old oil out but removing the lower hose will drain most of it.

 

[HyperPete 641]

12 minutes ago, 953 nut said:

You won't get 100% of the old oil out but removing the lower hose will drain most of it.

 

 

 

That's exactly what I needed.

Thank you!

[lynnmor 7,623]

I copied this from somewhere, maybe it contains some information you can use:

 

 C l a m p   t h e   s u p p l y   h o s e   t o   t h e   p u m p   a n d   r e m o v e   i t   f r o m   t h e   p u m p ,   t h e n   r e l e a s e   t h e   c l a m p .
 
 Y o u   a r e   n o t   g o i n g   t o   b e   a b l e   t o   d o   a   f u l l   f l u i d   c h a n g e   e a s i l y .   T h e   c y l i n d e r s   a r e   s t i l l   f u l l   o f   f l u i d   a n d   t h e y   h o l d   a   l o t   m o r e   t h a n   t h e   l i t t l e   b i t   l e f t   i n   t h e   b o t t o m   o f   t h e   r e s e r v o i r .   R e p l a c e   w h a t   y o u   c a n   d r a i n   a n d   c a l l   i t   a   d a y   i f   u s i n g   t h e   s a m e   t y p e   o f   f l u i d   t h a t   i s   i n   t h e   l o a d e r .   T h e   a d d i t i v e   p a c k a g e s   o f   t h e   v a r i o u s   f l u i d s   a v a i l a b l e   a r e   n o t   u s u a l l y   c o m p a t i b l e .
 
 I f   y o u   a r e   c h a n g i n g   t h e   t y p e   o f   f l u i d ,   y o u   r e a l l y   s h o u l d   d o   a   m o r e   c o m p l e t e   d r a i n   o f   t h e   s y s t e m ,   i n c l u d i n g   t h e   c y l i n d e r s .
 
 -   R a i s e   t h e   a r m s   a l l   t h e   w a y   a n d   c u r l   t h e   b u c k e t   i n t o   t h e   d u m p   p o s i t i o n .
 
 -   P l a c e   a   l e n g t h   o f   s t e e l   o n   t h e   g r o u n d   u n d e r   t h e   b u c k e t   e d g e   f o r   i t   t o   s k i d   o n   w h e n   t h e   a r m s   a r e   l o w e r e d .
 
 -   C o m m e n c e   t h e   d r a i n   p r o c e s s .
 
 -   L o w e r   t h e   a r m s   b y   g r a v i t y   ( n o t   t h e   e n g i n e )   u s i n g   t h e   a r m   c o n t r o l .
 
 -   W h e n   t h e   b u c k e t   c o n t a c t s   t h e   s k i d ,   a l s o   m o v e   t h e   c u r l   c o n t r o l   t o   r o l l   t h e   b u c k e t   b a c k .
 
 W h e n   t h e   b u c k e t   i s   s i t t i n g   l e v e l   o n   t h e   s k i d ,   t h e r e   i s   o n l y   a   l i t t l e   f l u i d   l e f t   i n   t h e   s y s t e m   a n d   t h e   t y p e   o f   f l u i d   c a n   b e   s a f e l y   c h a n g e d .
 
 -   R e c o n n e c t   t h e   h o s e   a n d   f i l l   t h e   r e s e r v o i r .
 
 T h e   p u m p   c o n t a i n s   v e r y   l i t t l e   f l u i d   b y   i t s e l f .   W h a t   i t   d o e s   c o n t a i n   i s   a d e q u a t e   f o r   s t a r t i n g   t h e   e n g i n e .   A n y   a i r   i n   t h e   s y s t e m   w i l l   b e   p u r g e d   o u t   b a c k   t o   t h e   r e s e r v o i r   f o r   v e n t i n g   s i m p l y   b y   c y c l i n g   t h e   c y l i n d e r s   o n c e   t h e   e n g i n e   h a s   b e e n   s t a r t e d .   T h e   f l u i d   i n   t h e   r e s e r v o i r   p r o v i d e s   a   h e a d   ( p o s i t i v e   p r e s s u r e )   f o r   t h e   p u m p   a n d   t h e   p o s i t i v e   d i s p l a c e m e n t   p u m p   w i l l   m o v e   t h e   a i r .
 
 -   C y c l e   t h e   a r m   c y l i n d e r s   f i r s t   a n d   r e p l e n i s h   t h e   r e s e r v o i r   w h e n   t h e   a r m   c y l i n d e r s   r e a c h   f u l l   e x t e n s i o n .
 
 -   C y c l e   t h e   c u r l   c y l i n d e r s   f u l l   s t r o k e   3   o r   4   t i m e s   w h i l e   t h e   a r m s   a r e   a t   f u l l   h e i g h t ,   f i n i s h i n g   w i t h   t h e   b u c k e t   c u r l e d

[HyperPete 641]

40 minutes ago, lynnmor said:

I copied this from somewhere, maybe it contains some information you can use:

 

 C l a m p   t h e   s u p p l y   h o s e   t o   t h e   p u m p   a n d   r e m o v e   i t   f r o m   t h e   p u m p ,   t h e n   r e l e a s e   t h e   c l a m p .
 
 Y o u   a r e   n o t   g o i n g   t o   b e   a b l e   t o   d o   a   f u l l   f l u i d   c h a n g e   e a s i l y .   T h e   c y l i n d e r s   a r e   s t i l l   f u l l   o f   f l u i d   a n d   t h e y   h o l d   a   l o t   m o r e   t h a n   t h e   l i t t l e   b i t   l e f t   i n   t h e   b o t t o m   o f   t h e   r e s e r v o i r .   R e p l a c e   w h a t   y o u   c a n   d r a i n   a n d   c a l l   i t   a   d a y   i f   u s i n g   t h e   s a m e   t y p e   o f   f l u i d   t h a t   i s   i n   t h e   l o a d e r .   T h e   a d d i t i v e   p a c k a g e s   o f   t h e   v a r i o u s   f l u i d s   a v a i l a b l e   a r e   n o t   u s u a l l y   c o m p a t i b l e .
 
 I f   y o u   a r e   c h a n g i n g   t h e   t y p e   o f   f l u i d ,   y o u   r e a l l y   s h o u l d   d o   a   m o r e   c o m p l e t e   d r a i n   o f   t h e   s y s t e m ,   i n c l u d i n g   t h e   c y l i n d e r s .
 
 -   R a i s e   t h e   a r m s   a l l   t h e   w a y   a n d   c u r l   t h e   b u c k e t   i n t o   t h e   d u m p   p o s i t i o n .
 
 -   P l a c e   a   l e n g t h   o f   s t e e l   o n   t h e   g r o u n d   u n d e r   t h e   b u c k e t   e d g e   f o r   i t   t o   s k i d   o n   w h e n   t h e   a r m s   a r e   l o w e r e d .
 
 -   C o m m e n c e   t h e   d r a i n   p r o c e s s .
 
 -   L o w e r   t h e   a r m s   b y   g r a v i t y   ( n o t   t h e   e n g i n e )   u s i n g   t h e   a r m   c o n t r o l .
 
 -   W h e n   t h e   b u c k e t   c o n t a c t s   t h e   s k i d ,   a l s o   m o v e   t h e   c u r l   c o n t r o l   t o   r o l l   t h e   b u c k e t   b a c k .
 
 W h e n   t h e   b u c k e t   i s   s i t t i n g   l e v e l   o n   t h e   s k i d ,   t h e r e   i s   o n l y   a   l i t t l e   f l u i d   l e f t   i n   t h e   s y s t e m   a n d   t h e   t y p e   o f   f l u i d   c a n   b e   s a f e l y   c h a n g e d .
 
 -   R e c o n n e c t   t h e   h o s e   a n d   f i l l   t h e   r e s e r v o i r .
 
 T h e   p u m p   c o n t a i n s   v e r y   l i t t l e   f l u i d   b y   i t s e l f .   W h a t   i t   d o e s   c o n t a i n   i s   a d e q u a t e   f o r   s t a r t i n g   t h e   e n g i n e .   A n y   a i r   i n   t h e   s y s t e m   w i l l   b e   p u r g e d   o u t   b a c k   t o   t h e   r e s e r v o i r   f o r   v e n t i n g   s i m p l y   b y   c y c l i n g   t h e   c y l i n d e r s   o n c e   t h e   e n g i n e   h a s   b e e n   s t a r t e d .   T h e   f l u i d   i n   t h e   r e s e r v o i r   p r o v i d e s   a   h e a d   ( p o s i t i v e   p r e s s u r e )   f o r   t h e   p u m p   a n d   t h e   p o s i t i v e   d i s p l a c e m e n t   p u m p   w i l l   m o v e   t h e   a i r .
 
 -   C y c l e   t h e   a r m   c y l i n d e r s   f i r s t   a n d   r e p l e n i s h   t h e   r e s e r v o i r   w h e n   t h e   a r m   c y l i n d e r s   r e a c h   f u l l   e x t e n s i o n .
 
 -   C y c l e   t h e   c u r l   c y l i n d e r s   f u l l   s t r o k e   3   o r   4   t i m e s   w h i l e   t h e   a r m s   a r e   a t   f u l l   h e i g h t ,   f i n i s h i n g   w i t h   t h e   b u c k e t   c u r l e d

 

Also very helpful, thank you!

[HyperPete 641]

Ok, I ran into problems with both the FEL and the hydro trans.  I created a new thread here: 

 

[HyperPete 641]

On 4/16/2025 at 10:09 AM, lynnmor said:

I copied this from somewhere, maybe it contains some information you can use:

 

 C l a m p   t h e   s u p p l y   h o s e   t o   t h e   p u m p   a n d   r e m o v e   i t   f r o m   t h e   p u m p ,   t h e n   r e l e a s e   t h e   c l a m p .
 
 Y o u   a r e   n o t   g o i n g   t o   b e   a b l e   t o   d o   a   f u l l   f l u i d   c h a n g e   e a s i l y .   T h e   c y l i n d e r s   a r e   s t i l l   f u l l   o f   f l u i d   a n d   t h e y   h o l d   a   l o t   m o r e   t h a n   t h e   l i t t l e   b i t   l e f t   i n   t h e   b o t t o m   o f   t h e   r e s e r v o i r .   R e p l a c e   w h a t   y o u   c a n   d r a i n   a n d   c a l l   i t   a   d a y   i f   u s i n g   t h e   s a m e   t y p e   o f   f l u i d   t h a t   i s   i n   t h e   l o a d e r .   T h e   a d d i t i v e   p a c k a g e s   o f   t h e   v a r i o u s   f l u i d s   a v a i l a b l e   a r e   n o t   u s u a l l y   c o m p a t i b l e .
 
 I f   y o u   a r e   c h a n g i n g   t h e   t y p e   o f   f l u i d ,   y o u   r e a l l y   s h o u l d   d o   a   m o r e   c o m p l e t e   d r a i n   o f   t h e   s y s t e m ,   i n c l u d i n g   t h e   c y l i n d e r s .
 
 -   R a i s e   t h e   a r m s   a l l   t h e   w a y   a n d   c u r l   t h e   b u c k e t   i n t o   t h e   d u m p   p o s i t i o n .
 
 -   P l a c e   a   l e n g t h   o f   s t e e l   o n   t h e   g r o u n d   u n d e r   t h e   b u c k e t   e d g e   f o r   i t   t o   s k i d   o n   w h e n   t h e   a r m s   a r e   l o w e r e d .
 
 -   C o m m e n c e   t h e   d r a i n   p r o c e s s .
 
 -   L o w e r   t h e   a r m s   b y   g r a v i t y   ( n o t   t h e   e n g i n e )   u s i n g   t h e   a r m   c o n t r o l .
 
 -   W h e n   t h e   b u c k e t   c o n t a c t s   t h e   s k i d ,   a l s o   m o v e   t h e   c u r l   c o n t r o l   t o   r o l l   t h e   b u c k e t   b a c k .
 
 W h e n   t h e   b u c k e t   i s   s i t t i n g   l e v e l   o n   t h e   s k i d ,   t h e r e   i s   o n l y   a   l i t t l e   f l u i d   l e f t   i n   t h e   s y s t e m   a n d   t h e   t y p e   o f   f l u i d   c a n   b e   s a f e l y   c h a n g e d .
 
 -   R e c o n n e c t   t h e   h o s e   a n d   f i l l   t h e   r e s e r v o i r .
 
 T h e   p u m p   c o n t a i n s   v e r y   l i t t l e   f l u i d   b y   i t s e l f .   W h a t   i t   d o e s   c o n t a i n   i s   a d e q u a t e   f o r   s t a r t i n g   t h e   e n g i n e .   A n y   a i r   i n   t h e   s y s t e m   w i l l   b e   p u r g e d   o u t   b a c k   t o   t h e   r e s e r v o i r   f o r   v e n t i n g   s i m p l y   b y   c y c l i n g   t h e   c y l i n d e r s   o n c e   t h e   e n g i n e   h a s   b e e n   s t a r t e d .   T h e   f l u i d   i n   t h e   r e s e r v o i r   p r o v i d e s   a   h e a d   ( p o s i t i v e   p r e s s u r e )   f o r   t h e   p u m p   a n d   t h e   p o s i t i v e   d i s p l a c e m e n t   p u m p   w i l l   m o v e   t h e   a i r .
 
 -   C y c l e   t h e   a r m   c y l i n d e r s   f i r s t   a n d   r e p l e n i s h   t h e   r e s e r v o i r   w h e n   t h e   a r m   c y l i n d e r s   r e a c h   f u l l   e x t e n s i o n .
 
 -   C y c l e   t h e   c u r l   c y l i n d e r s   f u l l   s t r o k e   3   o r   4   t i m e s   w h i l e   t h e   a r m s   a r e   a t   f u l l   h e i g h t ,   f i n i s h i n g   w i t h   t h e   b u c k e t   c u r l e d

 

I'm unable the empty the system of ATF well.  After going through this procedure and assuming it was empty, I filled with 10W30. 

 

When I jacked up the front of the tractor to drain the trans, over a quart of pretty pure ATF leaked out of the FEL breather at the fill plug.  I'm guessing the ATF is lighter, and sat on top of the motor oil.

 

I don't want to run a mix, and I feel that I'm now committed to 10W30.

 

How can I drain the system more thoroughly?  I even tried gently blowing air through the fill hole, but not more more fluid came out of the bottom hose.

 

⁉️🤔😵

[lynnmor 7,623]

14 minutes ago, HyperPete said:

 

I'm unable the empty the system of ATF well.  After going through this procedure and assuming it was empty, I filled with 10W30. 

 

When I jacked up the front of the tractor to drain the trans, over a quart of pretty pure ATF leaked out of the FEL breather at the fill plug.  I'm guessing the ATF is lighter, and sat on top of the motor oil.

 

I don't want to run a mix, and I feel that I'm now committed to 10W30.

 

How can I drain the system more thoroughly?  I even tried gently blowing air through the fill hole, but not more more fluid came out of the bottom hose.

 

⁉️🤔😵

Not knowing your exact system, I am at a total loss.  Is your loader tied in with the tractor transmission?  Any loader that I dealt with was completely separate and used hydraulic oil.

[HyperPete 641]

I'm pretty certain they are totally separate.  I see nothing in either manual about interconnection, and I see no tubing from the FEL system connected to the transmission.

[HyperPete 641]

So, I have been thinking about returning to transmission fluid.  It bugs me that I can only drain fluid from the right upright by removing a hose, and not at all from the left leg.  So, basically, it's impossible to get more than about 50% of the fluid out of the system as-is.  So I have not done anything since I drained & filled last.

I've thought about drilling a hole in the bottom of the left upright, threading it, and installing a drain plug so I can drain both sides..

 

Am I asking for trouble; will it depressurize / leak regardless of the kind of plug I use?  Can I just use a pipe thread plug with Teflon tape, or would I need some kind of compression fitting?  Are metal chips a serious concern if i use rare earth magnets around the hole I drill, and possibly grease on the drill bit?

[8ntruck 7,453]

You don't  want to use Teflon tape on threaded fittings in a hydraulic system.  Doing so introduces the possibility of slivers of Teflon tape contaminating the system - mechanically, not chemicaly.  The plant I retired from banned the use of Teflon joint tape for this reason.

[wallfish 17,597]

17 hours ago, HyperPete said:

So, I have been thinking about returning to transmission fluid.  It bugs me that I can only drain fluid from the right upright by removing a hose, and not at all from the left leg.  So, basically, it's impossible to get more than about 50% of the fluid out of the system as-is.  So I have not done anything since I drained & filled last.

I've thought about drilling a hole in the bottom of the left upright, threading it, and installing a drain plug so I can drain both sides..

 

Am I asking for trouble; will it depressurize / leak regardless of the kind of plug I use?  Can I just use a pipe thread plug with Teflon tape, or would I need some kind of compression fitting?  Are metal chips a serious concern if i use rare earth magnets around the hole I drill, and possibly grease on the drill bit?

There shouldn't be any fluid in the left upright unless someone modified it. The right upright is the only reservoir from the factory. Are there hoses or lines connected to it?

Waffling back and forth between fluids is just going to keep mixing fluids and take more effort. Pick one and stick with it and change the fluid a couple of times. Follow the draining instructions you posted for changing the type of fluid even though you are keeping it the same fluid and that will remove the most of the mixed fluid as well.

If you're getting a quart of ATF flowing out of the breather then jack it up even farther and get even more out first. (That seems like an excessive amount)

Drain per instructions, run and operate the system, rinse and repeat as long as necessary. Yeah it's a PITA, but once the fluid type was changed...

[HyperPete 641]

1 hour ago, wallfish said:

There shouldn't be any fluid in the left upright unless someone modified it. The right upright is the only reservoir from the factory. Are there hoses or lines connected to it?

Waffling back and forth between fluids is just going to keep mixing fluids and take more effort. Pick one and stick with it and change the fluid a couple of times. Follow the draining instructions you posted for changing the type of fluid even though you are keeping it the same fluid and that will remove the most of the mixed fluid as well.

If you're getting a quart of ATF flowing out of the breather then jack it up even farther and get even more out first. (That seems like an excessive amount)

Drain per instructions, run and operate the system, rinse and repeat as long as necessary. Yeah it's a PITA, but once the fluid type was changed...

 

yep, well, maybe ill stick to the 10w30 then.  I expect that a second fill & drain should clear the system pretty well, and the 3rd ffill should be fine.  I'm just frustrated by the ATF coming out after following the instructions to a T.  I keep thinking of my 2017 Ridgeline where you have to do 3 transmission fluid changes in a row to change most of the fluid since there is no way to drain the torque converter.  Danged engineers!

 

I operated it a little after the 1st change, so it should be pretty well mixed.

And no, now that you mention it, there are no lines to the left upright.  I don't know where that ATF came from.

To jack the front any higher, I'll have to remove the weight box.  It's already up about as high as I am able to jack it.

 

I have not brewed in decades, or I would "relax, and have a homebrew!"

Edited 19 hours ago by HyperPete

[wallfish 17,597]

1 hour ago, HyperPete said:

I have not brewed in decades, or I would "relax, and have a homebrew!"

You can order plans online for how to still some moonshine in small batches, which can be done right on the stove top! Get that brew going before the BFH comes out!!!! LOL

I've done it and it's pretty good too!

 

I think that ATF might be separating and floating to the top.

Suction it out off the top ?????

[HyperPete 641]

3 minutes ago, wallfish said:

You can order plans online for how to still some moonshine in small batches, which can be done right on the stove top! Get that brew going before the BFH comes out!!!! LOL

I've done it and it's pretty good too!

 

I think that ATF might be separating and floating to the top.

Suction it out off the top ?????

 

I think I'll stick with buying my small batch tequila.  Distilling myself sounds a lot like work, Agave will be hard to come by in PA, and unless it it made in Tequila, MX, it isn't tequila.

Sounds like a cool experiment, though!

 

I will give suctioning a shot, but I'd take the odds that once oil & ATF mix, it becomes a homogenous mixture.  It would be very helpful if that was not the case.

 

Oh, and I really appreciate your input & assistance!