Late 90's Boss Bobcat 763 Hydraulic cylinder removal (Boom)

[cmb7684]

My 763 was sitting up for a while as I tinkered with the spool valve repair that took me forever. Needless to say all went back together and so far no leak at the spool valves that I repaired. To make the spool valve repair I lifted the boom and locked it out with the orange safety arm lock. I guess the sun and elements beating on it along with sitting up was too much as the arm without the safety latch is leaking fluid out of the dust cover where the piston goes into the cylinder. As I was going back and forth on the pedals with the orange safety lock engaged trying to make it move enough to let me unlock the safety latch one the boom lift cylinders sprung a leak.
I have watched a few videos on how to rebuild the cylinder but I have found none that tell you a safe way to get it out.
To add insult to injury, I also have not been able to get the boom to lift all the way up to unlock the safety arm to let the boom down. The leak is bad enough to address it right away but no so bad it cant be run for a few minutes to let the boom down. I assume because the cylinders were locked in the up position and all the fluid leaked out of the machine during the spool valve repair the cylinders need to fill back with fluid in order to build enough pressure to lift the boom enough to disengage the safety latch to allow the boom to lower to the ground. The side that is leaking has filled with fluid and is moving that side of the boom up and down. The side of the boom with the safety cylinder lock out that is not leaking is the one that does not appear to try to move up or down to release the lock out.
So it brings me to a few questions:
1. What is he best way to get the air out of the system specially with a leak in the cylinder arm so the other cylinder will start to move?
2. If I have to remove the cylinder while the boom is in the air locked out from the other side, is it possible. Can the cylinder with the lock out hold the boom safely in place while I remove the boom cylinder on the opposite side?
3. Any good videos of removing the cylinder while the boom is in the air or on the ground?
4. What is the best method to replace from each position. I assume its best with the boom on the ground as if the one on the lock out side was leaking it would not be able to be locked out using the safety lock out. Can anyone direct me or steer me to any how to's on removing the cylinders that lift the boom? Also please include any suggestions on safety regardless of how basic it may seem.

5.

 

[Tazza]

Even with air, the cylinder should still lift. Get it up and remove the safety bar. Lower the boom and use a good piece of timber where the boom touches the front of the frame. This will make it so the arms sit up a little from the chassis. Remove the lines from inside the engine bay. Remove the pins and drop the cylinder down and it shoudl have enough space under the arms to slide out.
Remove gland and replace the seals.
Any issues, flick me an e-mail and i should be able to go into more detail if needed.

 

[jhatchett]

Even with air, the cylinder should still lift. Get it up and remove the safety bar. Lower the boom and use a good piece of timber where the boom touches the front of the frame. This will make it so the arms sit up a little from the chassis. Remove the lines from inside the engine bay. Remove the pins and drop the cylinder down and it shoudl have enough space under the arms to slide out.
Remove gland and replace the seals.
Any issues, flick me an e-mail and i should be able to go into more detail if needed.

I have a leaking lift cylinder as well and getting ready to replace the seals soon. I could use a part number for the seal kit and any tips or pointer to a youtube video for the process. 763 G series sn: 512255067

 

[Tazza]

I have a leaking lift cylinder as well and getting ready to replace the seals soon. I could use a part number for the seal kit and any tips or pointer to a youtube video for the process. 763 G series sn: 512255067

Get the ram off, remove the seals and take them to a hydraulic seal shop, they will mtch them for you.
Loader parts source sell them, but you'll have to make sure they send you the rite ones, they are about $25/30 a set from memory.

 

[jhatchett]

Get the ram off, remove the seals and take them to a hydraulic seal shop, they will mtch them for you.
Loader parts source sell them, but you'll have to make sure they send you the rite ones, they are about $25/30 a set from memory.

I ended up taking the machine to the shop and they replaced the seals for $100 while I watched. Mechanic raised the arm and locked in the safety bar, relieved the hydraulic pressure, popped out the forward pivot pin, lowered the cylinder with the rear pin still in place, unscrewed the cylinder, pulled the piston out and took it to the work bench. Replaced the seals and then put it back into the cylinder, screwed the cap back on, put the pin back in. raised/lowered a few times to get all the air out, topped up the hydraulic fluid, washed the machine and parked it next to my trailer. If it wasn't an hour drive each way I think I would use the bobcat shop more often.