ARK500 FEL leaks down slowly

[HyperPete 482]

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 482]

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 17,485]

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 7,557]

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 482]

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 17,485]

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) 11,243]

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

[HyperPete 482]

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 482]

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

 

[HyperPete 482]

Update: FEL is Ark 508QM

 

(Found my tractor, formerly for sale here.)

 

[HyperPete 482]

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 57,854]

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

 

[HyperPete 482]

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 7,557]

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 482]

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 482]

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

 

[HyperPete 482]

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 7,557]

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 482]

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.