Bobcat 331 Excavator Hydraulic Thumb problems

[Modn]

Looks correct. I wonder if it has a mate on the bottom side?

Good idea, I will take a look.

 

[kclark2227]

No disassembly of valve required. Just remove the plug cap currently in valve and install. If he has the hoses connected to correct coupler on the boom, the this plug goes in the top side of the valve as it sets in the machine.
It is shown in the installation instructions for the clamp (thumb) Bobcat sells for that machine. Here is clip from next page of instruction, shows better where it goes.
View attachment 447778

The only 331 models that did not have provision in the valve for port relief were very early models; all those with 5519 as first 4 digits of serial number and 521913973 and below. All others will accept simple port relief installation in not already factory equipped.

SSDoxie, I know this is an old post so I'm hoping you're still around. I have a '99 Bobcat 331 that doesn't have a thumb. I would like to put a thumb on it. It has the aux lines on the boom and the aux foot pedal on the left of the floor. My Bobcat dealer says that I need a port relief valve that is no longer made and would have to be some aftermarket part or buy one off of a salvaged unit. They are saying because its a '99 model that it needs it. They haven't looked up the serial number. They did print off the thumb installation instructions from Bobcat and from what it says, my Serial # should be ready to just put the thumb one and start working. Looking at what you stating in your post above that agrees with what I find. But I don't know how to follow these hydraulics and I don't know what to look for or where to look to see if I'm good to go or if I need to install port relief. My Serial # is 521917785. Thanks in advance.