The valve (spool) for the lift cylinders has to travel out of the valve futher than I would consider normal.. It only does it on the up motion. That would be out for the valve.. I first thought I had play in the linkage, but realized it was just excessive travel in the valve.. What would cause this and how to fix it? It is only in the up movement which is out in the spool valve.. There is no leakage, everything works good, has good lifting power. Just not very sensitive. Especially when compared to the tilt, and the up on the lift cylinder. Thanks
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Why do you feel there is excessive movement? Play in the linkages will make the pedal more more.
reaperman
Well-known member
- Joined
- Dec 18, 2011
- Messages
- 599
If you look at the linkage underneath the seat, you will notice the linkage for the tilt is strait in line with the hydro pump. Leaving hardly any places for slack. The linkage to raise/lower the boom has to make two separate 90 degree angles, plus a pivot in the linkage arms between those two angles. There is just too many areas for slop in the left side linkage system. There are even bushings in the pedal itself that can wear thin. We had a machine like this, it drove me nuts how far I had to move the pedal to make the arms react.
It is not slop in the linkage. I removed almost all of it. I originally thought it was that. But after removing slop. i noticed it still took alot of foot pedal to move.. After investigating and comparing the two valves i noticed the excessive stroke needed to move the boom. It is only when valve is being pulled out. It takes 2-3 times longer stroke to get the same movement as the other direction. It is smooth when it starts to move and has power, but the extra needed foot pedal is noticeable.. I can watch the difference at the spool valve in the different strokes in and out. Thanks you guys are great help.
I don't want to bet a dead horse , but my rehab is complete, and I still have the same question. I have basically zero slop in the linkage and foot pedal.. The Boom valve requires much more pedal movement distance to get the movement in the boom .. I am referring to the valve at the spool. The valve must be pushed in or puled out quite a bit. It works fine ,but I believe the extra stroke distance is not correct. My son ask if it could be because the boom weights more than the tilt when empty. More weight would require more fluid/ power to lift? i just find this odd and interesting. I have put many hours in this rehab and it is bugging me. The tilt will move with very little pedal movement.
Travel does not need to increase for extra load, it just means it takes longer to lift with less travel of the spool.
With the cab up, movig the pedal, watch the movement of the actual spool on the control valve. I still feel it could be slop or wear on the rubber and steel bushings. BUt if they are indeed tight, i have no idea what's going on, it is remotely possible someone replaced the spool with another one that was wrong, but i'd like to think that has not happened as they are generally matched to the hole, Bobcat do not sell jsut a spool, you need the entire housing.
flyerdan
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- Mar 7, 2009
- Messages
- 983
Just a swag on my part, but since there doesn't seem to be any wear or slop in the valve, is it possible that it was made that way for more precise positioning?
Id suggest downloading the component repair book and have a look at the diagrams. That's a lot easier than taking something apart. The valve body could be drilled differently to allow for a different flow pattern while still retaining the same seals for all three spools.
Thanks for the input. I agree it appears it is made that way.. The travel at the valve is where i first noticed it. I was tracking down slop and noticed the excessive travel.. It is quite noticeable when compared to the other valve. This is at the spool.. If someone thinks of it check there machine sometime.. It is a little difficult to do.. You have to have the cab up , machine running with the spool unlocked.. Safety could be a concern. Thanks for the help.
