manganos
Platinum Member
When I leave the tractor for a while. (parked for a week or so) and I come back. My BH is resting on the ground and the stabilizers are down a tad. Is it normal for them to drop a when parked? Thanks for the help.
BX 22 Hydraulics
- Thread starter manganos
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Steven
Gold Member
Re: BX 22 Hydrolics
I have a bx22 also and the stablizers drop about 1 inch or less if left for a week. not sure of the backhoe because i always drop it to the ground for safety reasons so the kids dont get hurt if the play with it even though they know not to. I'm not sure if this is a problem but know i know of two that do it.
I have a bx22 also and the stablizers drop about 1 inch or less if left for a week. not sure of the backhoe because i always drop it to the ground for safety reasons so the kids dont get hurt if the play with it even though they know not to. I'm not sure if this is a problem but know i know of two that do it.
This is no problem. All of the hydraulic valves on the tractor are known as "spool" valves. They have a control spool that slides in a machined, cast housing. As you move the joystick you slide the spool in the housing to open fluid paths to the different cylinder ports.
The clearance between the spool and housing is between 0.0005" and 0.0015". This clearance allows a small leakage to occur between the hydraulic ports in the valve. Since gravity causes pressure in the hydraulic cylinders due to holding up different implement parts, this pressure will cause a very slow leakage flow through the valve. While the flow rate is only a few drops per minute, over time the cylinders will "droop". More pressure on the cylinder, the faster it will go.
In larger construction machines (dozers, loaders, etc) they sometimes use what are called counterbalance or pilot operated check valves which can be made virtually leak free. This will hold the cylinders without drift at 5000 PSI. On our little machines, there is no reason to justify the cost for this design feature. I'm not sure, since I have yet to get my BX22 service manual (dealer is waiting for the factory), but the 3 PT control valve may be a leak free type valve to hold heavy implements in a position over long time periods.
BTW this is why you should use the BH holding pins when driving a distance or parking it for a longer period.
paul
The clearance between the spool and housing is between 0.0005" and 0.0015". This clearance allows a small leakage to occur between the hydraulic ports in the valve. Since gravity causes pressure in the hydraulic cylinders due to holding up different implement parts, this pressure will cause a very slow leakage flow through the valve. While the flow rate is only a few drops per minute, over time the cylinders will "droop". More pressure on the cylinder, the faster it will go.
In larger construction machines (dozers, loaders, etc) they sometimes use what are called counterbalance or pilot operated check valves which can be made virtually leak free. This will hold the cylinders without drift at 5000 PSI. On our little machines, there is no reason to justify the cost for this design feature. I'm not sure, since I have yet to get my BX22 service manual (dealer is waiting for the factory), but the 3 PT control valve may be a leak free type valve to hold heavy implements in a position over long time periods.
BTW this is why you should use the BH holding pins when driving a distance or parking it for a longer period.
paul
Carl_NH
Elite Member
- Joined
- Apr 5, 2002
- Messages
- 3,782
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- Coastal NH
- Tractor
- 01 Kubota B21TLB, 2010 Ferris 52" ZTR, Cub Cadet 1811, Gravely Super8
As Paul states, this is normal. My B21TLB stabilizers go down about a 1/4"in an idle week with the BH & FEL at rest.
I have a neighbor with a JD 310 and it sits for a week with the boom up - no real leakdown to speak of.
Carl
I have a neighbor with a JD 310 and it sits for a week with the boom up - no real leakdown to speak of.
Carl
Before I put the tractor up tonight I put the pins in to hold it. Thanks again.Worksmart
Silver Member
- Joined
- Jan 24, 2002
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- 226
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- S.E. Michigan
- Tractor
- L6060, BX22, 1953 Farmall Super A, 1949 Farmall Cub, 1964 International Cub, 1966 International Cub, 1976 International Cub
Mine too. Only 8 hrs on machine. I just use the pins. No big deal. C
