Bobcat 753 Auxillary Hydraulics

[candidcomrad]

For some reason unknown to me I try to engage my auxillary hydraulics and they will not stay engaged. I press the aux. button once and the first green light comes on and the I press the button once more and the second green light comes on. I actuate the trigger on the right handle and squeeze the trigger on the front of the right handle and it engages and operates the backhoe for about a minute and disengages and when attempting to reengage the aux. hydraulics it will allow one green light to come on but as soon as I hit the button for the second greenlght it does not come on and the first green light goes out. Can anyone help me out with this problem. I have tried calling the Bobcat dealer and they want to act all secretive about any advice. Thanks

 

[Tazza]

Does it blink at all?
I wonder if the coil may be faulty. If you lift the cab, you can remove the coils from the stems and swap them over, swap the leads too. See if it goes away. If so, you have a bad coil.

 

[candidcomrad]

Does it blink at all?
I wonder if the coil may be faulty. If you lift the cab, you can remove the coils from the stems and swap them over, swap the leads too. See if it goes away. If so, you have a bad coil.

Are these the two coils located on top of the pump mounted on the right hand side sitting in the seat below the cab? Thanks

 

[Tazza]

Are these the two coils located on top of the pump mounted on the right hand side sitting in the seat below the cab? Thanks

They should be on the control block. Right hand side when sitting in the seat.

 

[candidcomrad]

They should be on the control block. Right hand side when sitting in the seat.

I will try your idea in the morning and let you know how it goes. Is each coil controlling a different part of the hydraulic system? Like is one for the aux. and the other for the main hydraulics? Thanks

 

[Tazza]

I will try your idea in the morning and let you know how it goes. Is each coil controlling a different part of the hydraulic system? Like is one for the aux. and the other for the main hydraulics? Thanks

One makes the oil flow one way, the other makes it go the other.
Depending on your machine, there could be one or two more coils, these are your safety lock outs.

 

[candidcomrad]

One makes the oil flow one way, the other makes it go the other.
Depending on your machine, there could be one or two more coils, these are your safety lock outs.

I switched the coils and the connectors but had the same results. Works for a minute and disengages and will not reengage. I did notice that if I get the first green light on and hold the slide trigger to the right on the right control handle and not release it I can reach forward with my left hand and operate the backhoe but as soon as I release the slide trigger on the control handle it will not operate. Could my problem be in the control handle or the overhead contol engage switch? Thanks

 

[Tazza]

I switched the coils and the connectors but had the same results. Works for a minute and disengages and will not reengage. I did notice that if I get the first green light on and hold the slide trigger to the right on the right control handle and not release it I can reach forward with my left hand and operate the backhoe but as soon as I release the slide trigger on the control handle it will not operate. Could my problem be in the control handle or the overhead contol engage switch? Thanks

The thumb switch is for momentary operation, as you know. I believe the trigger is essentially the same, its not a click on, click off style so i suspect your handle should be ok. As you state the light goes off leads me to believe there is another fault, not the handle. If it was a wire shorting out for the switch it would turn on and off but not the green light on the panel....
I guess it could be a controller issue getting hot, but i'd suspect moisture in the connectors first, see if you can check the pins on the connectors first.

 

[candidcomrad]

The thumb switch is for momentary operation, as you know. I believe the trigger is essentially the same, its not a click on, click off style so i suspect your handle should be ok. As you state the light goes off leads me to believe there is another fault, not the handle. If it was a wire shorting out for the switch it would turn on and off but not the green light on the panel....
I guess it could be a controller issue getting hot, but i'd suspect moisture in the connectors first, see if you can check the pins on the connectors first.

I will give it a try first thing in the a.m. I disconnectted the backhoe attachment today but will give it a try. I am getting to the point where I don't have much use for the attachment and may just sell the thing since I use the bucket more around the yard. Thanks

 

[candidcomrad]

I will give it a try first thing in the a.m. I disconnectted the backhoe attachment today but will give it a try. I am getting to the point where I don't have much use for the attachment and may just sell the thing since I use the bucket more around the yard. Thanks

Gave it another try and had the same results. I also tried the aux. hyds. with nothing attached and it did engage and you could actually hear the pump but it disengaged as before. Thanks