B3030 relief valve

KennyV · Jun 7, 2006

I think Mad is right about the relief valve not being a prime suspect… If a work port had a relief spring that far off you would certainly notice it as being very weak in that function during normal use… KennyV.

KennyV · Jun 7, 2006

I think Mad is right about the relief valve not being a prime suspect… If a work port had a relief spring that far off you would certainly notice it as being very weak in that function during normal use… KennyV.

MadReferee · Jun 7, 2006

Is this excessive leakdown?

Once the valve spools have been used they start to wear. Spool rod surfaces with no tolerance when new now have some. Even the slightest scratch will cause some leakdown. Scratches can be caused by microscopic particules in the fluid and burrs and imperfections on the valve casting where it meets the spool rod (common with new equipment). Also, the relief and load check poppets may not be seated tightly due to crud. Since this is a fairly new tractor any of the above may be causing your leakdown. However, leakdown is inevitable and a fact of life.

BTW, if you decide to adjust the relief springs with shims to get additional oomph for your backhoe, make sure you do not exceed the system pressure. Doing so will negate the reason for having the reliefs. Use a proper gauge connected correctly.

MadReferee · Jun 7, 2006

Is this excessive leakdown?

Once the valve spools have been used they start to wear. Spool rod surfaces with no tolerance when new now have some. Even the slightest scratch will cause some leakdown. Scratches can be caused by microscopic particules in the fluid and burrs and imperfections on the valve casting where it meets the spool rod (common with new equipment). Also, the relief and load check poppets may not be seated tightly due to crud. Since this is a fairly new tractor any of the above may be causing your leakdown. However, leakdown is inevitable and a fact of life.

BTW, if you decide to adjust the relief springs with shims to get additional oomph for your backhoe, make sure you do not exceed the system pressure. Doing so will negate the reason for having the reliefs. Use a proper gauge connected correctly.

ovrszd · Jun 8, 2006

( Stef
Your logic sounds good…
Finding a leak down can be a problem. You might find a fast, like yours, using a stethoscope, either electronic or conventional. You will need to have everything around rather still and quiet, then as you near the leak you will hear it.
Multi viscosity oil can leak down where a strait weight may not. There are no real seals in many control valves, close machine tolerances usually give acceptable leak down, most leaks like you have outlined are in the control valve. Good luck and happy hunting.
Should you locate, post back with your findings…KennyV.
)

I agree with KennyV, leakdowns like you are describing are usually in the control valves. Not sure if this is excessive enough to justify warranty repair or if that's applicable???

ovrszd · Jun 8, 2006

( Stef
Your logic sounds good…
Finding a leak down can be a problem. You might find a fast, like yours, using a stethoscope, either electronic or conventional. You will need to have everything around rather still and quiet, then as you near the leak you will hear it.
Multi viscosity oil can leak down where a strait weight may not. There are no real seals in many control valves, close machine tolerances usually give acceptable leak down, most leaks like you have outlined are in the control valve. Good luck and happy hunting.
Should you locate, post back with your findings…KennyV.
)

I agree with KennyV, leakdowns like you are describing are usually in the control valves. Not sure if this is excessive enough to justify warranty repair or if that's applicable???