Hydraulic top link issues
- Thread starter mgraham112
- Start date
Leejohn
Elite Member
The best way to get the air out is get cyl all the way end. Then remove rod end hose then run the cyl all the way out. After all the way out just bump the control valve in to fill the unhooked hose with oil.
If you had done that when it was new there would not been any oil in the rod end. Now there is oil in it might get a little messy. You can take the rod quick connect couple then put the hose in a bucket to catch the oil.
If you had done that when it was new there would not been any oil in the rod end. Now there is oil in it might get a little messy. You can take the rod quick connect couple then put the hose in a bucket to catch the oil.
MtnViewRanch
Elite Member, Advertiser
- Joined
- Mar 19, 2005
- Messages
- 10,456
- Tractor
- Mahindra 7520, Mahindra 3215HST, Case 580 extendahoe, Case 310 dozer, Parsons trencher, Cat D6,
For sure air is the problem. Completely cycle (full strokes) in each direction 10-20 times. If you have a problem after that, then you have a real problem. 
LD1
Epic Contributor
^^^^agree. It's just air that hasn't been bled all out yet.
npalen
Elite Member
I had some issues with air in my top link cylinder and found, after Brian at MtnViewRanch suggested checking, that the weight of the implement was causing the cylinder to extend too fast. The pump was apparently unable to keep up with the demand of the cylinder.
Brian sent me a restrictor fitting which solved the problem for the most part.
Edit: For clarification, trying to get air out of the system by cycling the cylinder "up and down" was seemingly pulling air into the cylinder as the load was dropping too fast.
Brian sent me a restrictor fitting which solved the problem for the most part.
Edit: For clarification, trying to get air out of the system by cycling the cylinder "up and down" was seemingly pulling air into the cylinder as the load was dropping too fast.
Last edited:
MtnViewRanch
Elite Member, Advertiser
- Joined
- Mar 19, 2005
- Messages
- 10,456
- Tractor
- Mahindra 7520, Mahindra 3215HST, Case 580 extendahoe, Case 310 dozer, Parsons trencher, Cat D6,
In reality, the full stroke cycling should be done with zero load on the unit. After a few different situations, what I have found is that over all, it has worked out best to have the flow restrictors on both ports.
OP
mgraham112
Gold Member
- Joined
- Feb 11, 2013
- Messages
- 313
- Location
- SC
- Tractor
- long 2460 - belarus 250 - JD 4230 - Kioti DK40SE
Well... I had a few minutes today and I cycled it numerous times and it is still happening. I'll take the cylinder off and try that route
ovrszd
Epic Contributor
- Joined
- May 27, 2006
- Messages
- 33,499
- Location
- Missouri
- Tractor
- Kubota M9540, Ford 3910FWD, Ford 555A, JD2210
I've had this problem on my Kubota for four years.
I got a pair of restrictors from Brian and tried them. They slowed my top link movement to the point of causing a slight squeal what activating that valve. Same problem existed.
I thought it might be a problem in the cylinder. But I've been "scolded" for suggesting it's possible for the cylinder to act like that.
Talked to a friend that's a tractor mechanic. He asked me if my "tank" line goes into the tank below the oil level? I don't know if it does or not. He said that's the only place it could be sucking air from.
I've just accepted it.
Curious to hear a solution for yours. Be sure to post any outcome.
I got a pair of restrictors from Brian and tried them. They slowed my top link movement to the point of causing a slight squeal what activating that valve. Same problem existed.
I thought it might be a problem in the cylinder. But I've been "scolded" for suggesting it's possible for the cylinder to act like that.
Talked to a friend that's a tractor mechanic. He asked me if my "tank" line goes into the tank below the oil level? I don't know if it does or not. He said that's the only place it could be sucking air from.
I've just accepted it.
Curious to hear a solution for yours. Be sure to post any outcome.
MtnViewRanch
Elite Member, Advertiser
- Joined
- Mar 19, 2005
- Messages
- 10,456
- Tractor
- Mahindra 7520, Mahindra 3215HST, Case 580 extendahoe, Case 310 dozer, Parsons trencher, Cat D6,
I've had this problem on my Kubota for four years.
I got a pair of restrictors from Brian and tried them. They slowed my top link movement to the point of causing a slight squeal what activating that valve. Same problem existed.
I thought it might be a problem in the cylinder. But I've been "scolded" for suggesting it's possible for the cylinder to act like that.
Talked to a friend that's a tractor mechanic. He asked me if my "tank" line goes into the tank below the oil level? I don't know if it does or not. He said that's the only place it could be sucking air from.
I've just accepted it.
Curious to hear a solution for yours. Be sure to post any outcome.
Richard, a couple of things. First, because you don't like how slow the unit worked with the size restrictors I provided, drill them out to .070. Second, did you try feathering the valve at all?
I have had 1 customer that I know of where it took 30 complete cycles to get all the air out of the cylinder and hoses. Typically it should only take 5-10 complete cycles. I have had a few customers where it was 15- 20 complete cycles.
If air is getting in, then something some where is wrong.
When the rod springs back as in the Op's video, that is a vacuum and most likely from the cylinder getting pulled out faster than the oil can get in and will continue to happen until either he starts feathering the control or restrictors are installed, at a minimum of on the rod side of the unit.
These cylinders should be close to rock solid, next to no movement at all, after all they should be full of oil.
On a side note, my top links do move in and out on their own, typically about 1/8" due to the flexing (expansion) of the hoses when additional working pressures are put on the links.