Backhoe thumb retrofit

[wdchyd]

Regarding the "Cushion Valve"on thumb cyls....I've been doing this for years but someone here on TBN (Don't recall who:ashamed mentioned it only works on dual cyl setups (similar to plow/BH swing circuits ect..).....

Thinking about it, when used on single cyl/double acting, the volume of oil from base end of cyl is larger displacement than rod end, thus resulting in unwanted intensification during induced load from bucket cyl force.....No??

IIRC the previous thread that this was brought up was a Volvo Mini Excavator with thumb cyl failure......

(Added: BCANTELL's Thread on "Mini Ex Thumb" & Stonehaller suggestion re: cushion valve)

 

[bobsphotos]

I plumbed up the crossover valve tonight and I have to report that it works awesome. I was able to adjust the extend circuit of the thumb cylinder so that no matter where it is, it cannot move the bucket and vice-versa. Thanks KennyD for the fix and thanks to all those that chimed in to help.

 

[kennyd]

I plumbed up the crossover valve tonight and I have to report that it works awesome. I was able to adjust the extend circuit of the thumb cylinder so that no matter where it is, it cannot move the bucket and vice-versa. Thanks KennyD for the fix and thanks to all those that chimed in to help.

Nice job Bob:thumbsup: Thanks for reporting back.