Woods BH75 Pressure hold issue

[Jass]

I have a new-to-me 2006 Woods BH2500-1 frame mounted backhoe with a Woods PTO hydraulic pump and the pressure does not hold. The backhoe digs fine and has seemingly good downward digging pressure, but if you raise the boom and the outriggers all up completely they all immediately start to lose pressure and begin dropping towards the ground. The fluid level in the onboard tank is full. Has anyone else experienced this issue? Any thoughts on what the issue might be that is causing this issue? Any/all help appreciated

 

[TheOldHokie]

I have a new-to-me 2006 Woods BH2500-1 frame mounted backhoe with a Woods PTO hydraulic pump and the pressure does not hold. The backhoe digs fine and has seemingly good downward digging pressure, but if you raise the boom and the outriggers all up completely they all immediately start to lose pressure and begin dropping towards the ground. The fluid level in the onboard tank is full. Has anyone else experienced this issue? Any thoughts on what the issue might be that is causing this issue? Any/all help appreciated

Thats three seoarate circuits and there are basically two routes for that leakdown to occur:

1) Via the seals in the cylinders
2) Via the spools in the control valve.

Easy to diagnose which way its going. Fixing it maybe not so easy.

Dan

 

[Jass]

It would seem odd that all of the cylinders would have the seals go out at roughly the same time. Any suggestions on diagnosing and isolating to one or the other?

 

[TheOldHokie]

It would seem odd that all of the cylinders would have the seals go out at roughly the same time. Any suggestions on diagnosing and isolating to one or the other?

It would be even odder that three different valves went bad. Quit possibly its some of both

Start with the outrigger cylinders which are easy to access.

1. Raise one stabilizer and chain it up.
2. Remove the base end hose and plug/cap the port on the cylinder.
3. Start tractor, move valve to raise (retract) position, and hold it there.

If the cylinder tries to extend the piston seals are leaking. Rinse and repeat with other cylinders.

Dan

 

[Jass]

Thanks. Just to clarify, on step 2 you indicate to "remove the base end hose" - is that the hose that would be closest to the ground when the outrigger is fully extended?
Then, on step 3, is that for the same stabilizer that was fully raised up and chained up in step #1?
Finially, again on step 3, if you try to raise (retract) that same stabilizer, isn't it already supposed to be fully raised. Not clear how that cylinder would extend if attempting to raise (retract)?
Sorry for being dense on this, and appreciate your suggestions.

 

[TheOldHokie]

Thanks. Just to clarify, on step 2 you indicate to "remove the base end hose" - is that the hose that would be closest to the ground when the outrigger is fully extended?
Then, on step 3, is that for the same stabilizer that was fully raised up and chained up in step #1?
Finially, again on step 3, if you try to raise (retract) that same stabilizer, isn't it already supposed to be fully raised. Not clear how that cylinder would extend if attempting to raise (retract)?
Sorry for being dense on this, and appreciate your suggestions.

Asking questions is how we learn and those are good questions.

1. The base end is the end opposite the rod end
2. You are testing on the cylinder that has been raised and supported.
3. If the cylinder is leaking internally the retract pressure will leak past the seals to the base end and equalize on both sides of the piston. Now the tricky part. Because the cross sectional area of the base side of the piston is greater than the cross sectional area of the rod side the net force on the rod will be outward (extend). Thats how we know the seals are leaking.

Dan

 

[Russell King]

deleted

 

[Jass]

Asking questions is how we learn and those are good questions.

1. The base end is the end opposite the rod end
2. You are testing on the cylinder that has been raised and supported.
3. If the cylinder is leaking internally the retract pressure will leak past the seals to the base end and equalize on both sides of the piston. Now the tricky part. Because the cross sectional area of the base side of the piston is greater than the cross sectional area of the rod side the net force on the rod will be outward (extend). Thats how we know the seals are leaking.

Dan

Okay, I performed the test described on both outriggers and sure enough the cylinders wanted to extend when I held the levers in the retract position. So, I assume all the cylinders need new seals installed, correct?

If that is the case and they all need a rebuild, how difficult are these to rebuild? I am pretty mechanically inclined so am willing to tackle unless there are all sorts of real specialized tools involved?

If I do tackle the rebuild, might you have a recommendation for the best place to get parts, and any idea if there is one kit for all of the cylinders?

Thanks for your inputs on all of this.

 

[TheOldHokie]

Okay, I performed the test described on both outriggers and sure enough the cylinders wanted to extend when I held the levers in the retract position. So, I assume all the cylinders need new seals installed, correct?

If that is the case and they all need a rebuild, how difficult are these to rebuild? I am pretty mechanically inclined so am willing to tackle unless there are all sorts of real specialized tools involved?

If I do tackle the rebuild, might you have a recommendation for the best place to get parts, and any idea if there is one kit for all of the cylinders?

Thanks for your inputs on all of this.

Seal kits from a Woods dustributor. Messicks wants $38 per stabilizer.

Dan