Hydraulic Cylinder Operation

[NordTrac]

Got a brand new pull-type snowblower (Meteor SB78-PT) late November. Right from the start, the hydraulic cylinder controlling the vertical deflector would act up. It would move once by about 6" (not the full stroke) and then by ever smaller distance until it seemed to lock up.

Since the hydraulic motor for the rotation worked fine, I swapped the remote circuits and got the same result. I then swapped circuit polarity and again, same behavior. I contacted the dealer and he sent me a new cylinder that I finally had the opportunity to install this weekend... no change!

Now I'm suspecting something wrong with the remotes I had installed by the dealer. Swapped circuits and polarity again without luck. Finally, with RPMs around 1000 and moving the remote circuit lever by a tiny amount, the cylinder started to behave normally over the full stroke repeatably. However, if I moved it too much it would locks again. So, I'm now thinking that the original cylinder was fine too and just needs very small hydraulic flow to activate properly.

I'm not familiar with hydraulics. Is this normal behavior? Should I add some sort of restrictor to the circuit?

 

[McMXi]

I've run a Land Pride SB1574 behind the MX6000HSTC with factory rear remotes for five years now and never had a problem with the deflector cylinder or rotation motor and that's with full factory flow.

Currently I'm running rotation and deflection off a Summit Hydraulics multiplier with restrictors. This is the first winter I've experienced issues with rotation due to ice. When I ran rotation off one of the standard rear remotes there was enough flow to break any ice bonds that were blocking the ring gear. With restrictors I have to be more diligent about clearing off the rotation ring. I plan on opening up the restrictors this spring when it's time to get the flail back on.

 

[Jsjac]

Is there some kind of load holding valve to keep the cylinder from moving when the valve is not stroked?
If there is a load holding valve setup the pressure on the lock check valves may need to be lowered.
Maybe a picture of the plumbing to the cylinder on the snow blower?

 

[#40Fan]

With the cylinder removed, does the deflector move freely?

 

[Like Tractors]

The hydraulic couplers on the hoses are the problem most likely, if the dimensions aren't correct, under high flow one will check fluid flow. Farm experience as a kid tells me this.

 

[TheOldHokie]

Got a brand new pull-type snowblower (Meteor SB78-PT) late November. Right from the start, the hydraulic cylinder controlling the vertical deflector would act up. It would move once by about 6" (not the full stroke) and then by ever smaller distance until it seemed to lock up.

Since the hydraulic motor for the rotation worked fine, I swapped the remote circuits and got the same result. I then swapped circuit polarity and again, same behavior. I contacted the dealer and he sent me a new cylinder that I finally had the opportunity to install this weekend... no change!

Now I'm suspecting something wrong with the remotes I had installed by the dealer. Swapped circuits and polarity again without luck. Finally, with RPMs around 1000 and moving the remote circuit lever by a tiny amount, the cylinder started to behave normally over the full stroke repeatably. However, if I moved it too much it would locks again. So, I'm now thinking that the original cylinder was fine too and just needs very small hydraulic flow to activate properly.

I'm not familiar with hydraulics. Is this normal behavior? Should I add some sort of restrictor to the circuit?

What is this 'polarity" that you are switching?

Are these factory remotes?

Cylinders dont care about flow rates.

Dan

 

[GreensvilleJay]

curious, found this site.

Hydraulic Cylinder Speed Calculator

put in 6GPM, 2.5" bore,8" long 1" shaft..... takes like 1.4 SECONDS to extend !
I assume 6 GPM, cylinder is 2.5x8 from mfr, my guess on the shaft

It seems to be a pretty 'stout' cylinder to move the deflector

'polarity' refers to how the hoses are connected.since both couplers are females, either pulling back or pushing forward can control up, simply by changing the 'polarity' of the hoses.

the higher the GPM the faster the ram moves. @1GPM it'll take 10 seconds

 

[Kennyd4110]

The hydraulic couplers on the hoses are the problem most likely, if the dimensions aren't correct, under high flow one will check fluid flow. Farm experience as a kid tells me this.

I was going to say basically the same...

Either incompatible or a bad QD.

 

[TheOldHokie]

[

I was going to say basically the same...

Either incompatible or a bad QD.

Owners manual description for the couplers is "Agri-ball tip" The other set seems to work so incompatible seems unlikely.

OP can remove the coupler on the rod end hose and stick the hose in a bucket or the hydraulic filler. If the problem goes away its probably a bad tip.

Dan

 

[PoTreeBoy]

You're not trying to use your loader controls for this, are you?

 

[McMXi]

The problem follows the hoses used for the cylinder since swapping remotes and swapping cylinders didn't correct the problem. It does seem likely that the problem is one of the couplers on the end of the hoses connected to the cylinder, or a problem with the hose itself. Maybe swap the hoses from the rotation motor to the deflector cylinder and see if the problem goes away.

 

[NordTrac]

With the cylinder removed, does the deflector move freely?

Yes, it does move freely

 

[NordTrac]

What is this 'polarity" that you are switching?

Are these factory remotes?

Cylinders dont care about flow rates.

Dan

Polarity was meant to convey swapping both hoses on the same circuit. Don't know of a better word to describe this as opposed to switching circuits.

They are Kubota remotes installed when I bought the tractor used.

 

[NordTrac]

You're not trying to use your loader controls for this, are you?

No. Using rear remotes.

 

[NordTrac]

The problem follows the hoses used for the cylinder since swapping remotes and swapping cylinders didn't correct the problem. It does seem likely that the problem is one of the couplers on the end of the hoses connected to the cylinder, or a problem with the hose itself. Maybe swap the hoses from the rotation motor to the deflector cylinder and see if the problem goes away.

I need to swap back to the original cylinder next weekend. I'll swap the hoses from the motor to the cylinder and see what happens.

 

[NordTrac]

Is there some kind of load holding valve to keep the cylinder from moving when the valve is not stroked?
If there is a load holding valve setup the pressure on the lock check valves may need to be lowered.
Maybe a picture of the plumbing to the cylinder on the snow blower?

Here's a picture of the original cylinder after I disconnected the hoses. I forgot to take the cylinder part number to research its design features.

 

[TheOldHokie]

Here's a picture of the original cylinder after I disconnected the hoses. I forgot to take the cylinder part number to research its design features.
View attachment 168547

The cylinder is not your problem. Its a vanilla double acting cylinder and about as simple as it gets.

Do the remote valves have a float position? I am guessing you dont know what that means.

I suggest you conduct a quick and simple test of the hose connections.

Disconnect both hoses at the cylinder, put the ends in a bucket, and start the tractor.

Move the control lever full down. You should get a strong continuos flow from one hose.

Pull the lever full up and you should get the same flow from the other cylinder.

If you dont get good flow in each direction somethings wrong at the valve or outlets.

Dan

 

[Kennyd4110]

Polarity was meant to convey swapping both hoses on the same circuit. Don't know of a better word to describe this as opposed to switching circuits.

It was a perfect way to describe it.

 

[LorenS]

The problem follows the hoses used for the cylinder since swapping remotes and swapping cylinders didn't correct the problem. It does seem likely that the problem is one of the couplers on the end of the hoses connected to the cylinder, or a problem with the hose itself. Maybe swap the hoses from the rotation motor to the deflector cylinder and see if the problem goes away.

Since the problem moved with the hose and it DOES work at very low flow rate, I would suspect an obstruction in the hose (maybe even part of I the hose itself from when the assembly was constructed) is acting like a spring-loaded check valve.

 

[TheOldHokie]

Since the problem moved with the hose and it DOES work at very low flow rate, I would suspect an obstruction in the hose (maybe even part of I the hose itself from when the assembly was constructed) is acting like a spring-loaded check valve.

Would you care to offer a way to actually test that theory?

Dan