backhoe problems

Will78 · Jun 26, 2011

Hoe is one year old and I only have 500 psi at the dipper stick cylinder. 1000 PSI at the bucket cylinder. The boom has 2750 PSI. The dipper and bucket also leak off when extended. New pump and new cylinders on the hoe. I guess the last guy was throwing parts at it to try and fix it. Couldn't get it fixed and sold it to me. I'm thinking I need to look at the control valves. I noticed he used teflon tape on a few fitting. Wondering if I have a valve sticking or leaking?

J_J · Jun 27, 2011

Was that the relief pressure on the boom cyl? If the other cyl can't make the pressure, then they are probably worn. You could take the hose with the good pressure and attach it to any of the other cyl and check the pressure to eliminate worn valve, and verify which BH cyl are good.

Cidertom · Jun 27, 2011

relief valves shot. Failed open or have busted springs. My guess.

Will78 · Jun 27, 2011

I checked all the vales today and everythig looked fine. The PSI check is at the end of the line that hooks to the cylinder so the cylinder shouldn't be the problem. It looks like the adjustment has been messed with. The cap has obviously been opened. I'm going to put the gauge back on the end of the lines and try to adjust the PSI.

J_J · Jun 27, 2011

Just because you get good pressure at the cyl hose, only means that you have good pressure. The cyl could still be worn and bypassing. If you install a hyd gage at the input to the FEL valve, any valve you operate will show the pressure for the cyl you are activating. A good cyl will show relief pressure if maxed out.

Will78 · Jun 28, 2011

I think I follow you now. I'm not a bright one! lol. I'll play around again tomorrow.

Will78 · Jun 29, 2011

Just got off the phone with Tommy, the owner of affordable tractor. Could not have been more helpful. Very nice guys to work with! Very imprressed with his willingness to walk me thru everything. Especially since I got the hoe used and haven't spent any money with him yet. He also has a lot of knowledge to share about the equipment he sells.

Also like to thank you guys for your help also.