aux hydraulics had a mind of their own- dangerous - could use some help

[clydesdale]

Hi, I have a 2010 bobcat s150 with aux hydraulics. I bought the machine used 1.5 yrs ago. It has about 775 hours on it. I am using it around my house. It does not get used hard and this is my first skid steer and I am not a skilled operator, as I have about 30 hours on the machine. But, here is my issue. My aux hydraulics sometimes act erratically. For example, I was using the plow yesterday and angled the plow with the thumb control on the right stick. I angle it all the way to the right, let go and the plow angled all the way back to the left, violently. It did this twice on me. So, i would lower the throttle before I would angle the plow. Once it stays put for a few seconds it is fine. It is just when you initially angle it. It has also done this with the combination bucket. When i use the thumb to open the clamshell, it might then close unexpectedly right after I open it. It is as if the thumb control malfunctions. My brother thought there could be air in the line. Any thoughts? Thanks.

 

[bobbie-g]

On all my machines, the thumb control will make the hydraulic fluid move in either direction as you described. But, the right trigger switch will make the hydraulics move in only one direction. I have to be careful to keep my trigger finger away from the trigger. I've seen most of the behavior you describe when I've inadvertently pulled the trigger. See if that causes the symptoms you are seeing. Further, I think the trigger puts the hydraulics in max flow, whereas the thumb switch _should_ provide some variable control. On my machines, the variable control is mostly in my imagination. Let the forum know if this is your issue. ---Bobbie-G

 

[clydesdale]

On all my machines, the thumb control will make the hydraulic fluid move in either direction as you described. But, the right trigger switch will make the hydraulics move in only one direction. I have to be careful to keep my trigger finger away from the trigger. I've seen most of the behavior you describe when I've inadvertently pulled the trigger. See if that causes the symptoms you are seeing. Further, I think the trigger puts the hydraulics in max flow, whereas the thumb switch _should_ provide some variable control. On my machines, the variable control is mostly in my imagination. Let the forum know if this is your issue. ---Bobbie-G

I don't think that is it. I don't think the trigger does anything, except the back up beep. I can hit the trigger and it makes a horn like beep sound from the back up beeper. I just can't remember if it is the left trigger or right trigger that does that.

 

[clydesdale]

I don't think that is it. I don't think the trigger does anything, except the back up beep. I can hit the trigger and it makes a horn like beep sound from the back up beeper. I just can't remember if it is the left trigger or right trigger that does that.

Well, you are correct sir. If I use the left trigger, I get a back up beep horn. But, if i use the right trigger, boom, full hydraulics and plow violently goes right. I did it twice to confirm. I need the plow to work, so I didn't keep doing it. I then used the thumb trigger and it was like the hydraulics were a little unhappy. So.... I am a total rookie. I have been spooked so I shut the hydraulics off when I pull the machine into the garage. I wasn't sure if it would freak out and blast something in the garage. So, what is the purpose of this trigger function? What attachnents would use that? I guess the solution is stay the hell away from it? Thanks.

 

[BC873G]

Well, you are correct sir. If I use the left trigger, I get a back up beep horn. But, if i use the right trigger, boom, full hydraulics and plow violently goes right. I did it twice to confirm. I need the plow to work, so I didn't keep doing it. I then used the thumb trigger and it was like the hydraulics were a little unhappy. So.... I am a total rookie. I have been spooked so I shut the hydraulics off when I pull the machine into the garage. I wasn't sure if it would freak out and blast something in the garage. So, what is the purpose of this trigger function? What attachnents would use that? I guess the solution is stay the hell away from it? Thanks.

I like to use the trigger when operating a tree shear. Hit the trigger and the shear will close automatically. A lot better than holding the thumb switch until it closes. You have to hit the trigger a second time though to stop. It will not stop on its own when the machine loads up.

 

[bobbie-g]

I like to use the trigger when operating a tree shear. Hit the trigger and the shear will close automatically. A lot better than holding the thumb switch until it closes. You have to hit the trigger a second time though to stop. It will not stop on its own when the machine loads up.

Tnx for the feedback! Glad it all makes sense to you now. On my snowplow, I installed a needle valve in one of the hydraulic lines. I just adjust the valve to pinch down the flow for a nice gentle action on the plow when I use my thumb in either direction. Yes, I know that puts more pressure on the line(s), but I'm guessing everything is designed to take that pressure. With a backhoe attachment, I have to turn on the hydraulics full time with the trigger, then get on the backhoe to operate it. I also run a mower and lock the mower on with the trigger. And good tip from BC873G on the tree shear. I have one and never thought to use the trigger! Love it! --- Bobbie-G

 

[clydesdale]

Tnx for the feedback! Glad it all makes sense to you now. On my snowplow, I installed a needle valve in one of the hydraulic lines. I just adjust the valve to pinch down the flow for a nice gentle action on the plow when I use my thumb in either direction. Yes, I know that puts more pressure on the line(s), but I'm guessing everything is designed to take that pressure. With a backhoe attachment, I have to turn on the hydraulics full time with the trigger, then get on the backhoe to operate it. I also run a mower and lock the mower on with the trigger. And good tip from BC873G on the tree shear. I have one and never thought to use the trigger! Love it! --- Bobbie-G

Thanks guys. So, do I have this right....I can angle the plow and get full violent plow angle, hit the trigger and it would stop? Or would it reverse? I remember when using the combo bucket it seemed to just start opening and closing. What SHOULD happen with the trigger with the plow and with the combo bucket? Thanks so much guys.