763 questions

[theboogers]

i got a older 773 wiith 400 hours on it from a farmer i know. real clean. anyhow i got a old, clean with new hoses, but working d100 case backhoe attachment. took me a long time to get the hydraulics to attach. the quick disconnect would not go on. i tried to turn key to left to drain off pressure but it still wouldn't work. i had to break the coupling at the qd to relieve the pressure then attach. took forever to learn how to bypass hand controls on bobcat to allow working of attachment. backhoe worked real nice, but it has a lot of sticks for the movement. not as nice as kubota unit i used with just 2 sticks. it will take a little getting used to. my question is even at a idle the backhoe works real fast. is there a way to slow down the hydraulics a little to adjust the backhoe movements? do i have to put a relief valve somewhere to really let pressure off of system on 763 to allow attachment to pop on? is there a relay not opening releasing the pressure enough? i waited about 10 15 seconds for the pressure to release without any luck. thanks,

 

[thetool]

I am not familiar with the backhoe, but some things I thought about--
Seems to me, if your control valve is internally tight, and you neutral the sticks, the only pressure you have in the aux lines is between the loader control valve and the backhoe control valve. Electric aux controls can be powered up, engine off, and wiggled to relieve this pressure and make it so you can easily remove your couplers.
If your valve is not internally tight, and your backhoe parts have any part not at rest on the ground or against a support lock pin, gravity will pressure up the system and make coupler removal difficult.
You said that it moves too quickly--is there not "feather" in the controls? Does it seem like when you slightly stroke a lever the flow is suddenly wide open? This could indicate a problem in the control valve, or you may have a cheap control valve without feather cutouts in the spools. You could have old pieces of rubber debris in the valve, causing it to bang open and shut when you stroke your lever. You could have spool centering spring problems causing this also. "Too fast" means to me either actually too fast or lack of fine control or "feather," two separate issues but often called by the same name.
Or, the backhoe could just be for a smaller machine than you have-small cylinders and such-I don't know.
Good Luck

 

[theboogers]

I am not familiar with the backhoe, but some things I thought about--
Seems to me, if your control valve is internally tight, and you neutral the sticks, the only pressure you have in the aux lines is between the loader control valve and the backhoe control valve. Electric aux controls can be powered up, engine off, and wiggled to relieve this pressure and make it so you can easily remove your couplers.
If your valve is not internally tight, and your backhoe parts have any part not at rest on the ground or against a support lock pin, gravity will pressure up the system and make coupler removal difficult.
You said that it moves too quickly--is there not "feather" in the controls? Does it seem like when you slightly stroke a lever the flow is suddenly wide open? This could indicate a problem in the control valve, or you may have a cheap control valve without feather cutouts in the spools. You could have old pieces of rubber debris in the valve, causing it to bang open and shut when you stroke your lever. You could have spool centering spring problems causing this also. "Too fast" means to me either actually too fast or lack of fine control or "feather," two separate issues but often called by the same name.
Or, the backhoe could just be for a smaller machine than you have-small cylinders and such-I don't know.
Good Luck

thanks for the reply. i was told later by someone else to turn the ignition on and use the aux controls to let off pressure. i am looking into needle valves to reduce the swing speed of the backhoe, which is a very old unit. it can be slow but takes a lot of concentration to keep slow.

 

[jerry]

thanks for the reply. i was told later by someone else to turn the ignition on and use the aux controls to let off pressure. i am looking into needle valves to reduce the swing speed of the backhoe, which is a very old unit. it can be slow but takes a lot of concentration to keep slow.

On the backhoe take the swing hoses off the control valve block and remove the adapter fitting to see if there is a restrictor washer in the line. On ours there is a brass washer .200 thick with 1/8 hole in it on both swing lines. I have the double ended cylinder gear and pinion swing not the chain.