Replacing Spool Seals On 763 Control Valve

Discovered a new leak the other day and thought others might want to know what I did to remedy the problem. Here are the notes I made to myself just in case I have to do another, or heaven forbid this one again. The first ones lasted 2600 hours and are replaced with what I think are a superior replacement so they should out last me.


It is a good idea to drain the hydraulic fluid first so it won't run out when you pull the spools. Lock the loader arms in the up position with the orange bar to make access over the side of the machine to the control valve.
When replacing the front and back seals of the two spools in the control valve remove the front rubber covers and seals first. There are two screws that hold each cover on and are hard to get to. It is easier if you first remove the emergency release valve and a couple of the lines to the control valve. After removing the two front boots and you can remove the top valve and it will just come right out from the back with little problem and one seal attached to the spool, then sticking your finger in the front hole remove the other seal. The bottom valve will be easier to access when the top one is removed, and comes out the same way. When replacing the seal on the spools make sure you take notice of the way it goes on, with the raised bump on the OD of the seal to the inside of the control valve (which at first appears wrong). When you replace the front seal behind the boot it goes the same way bump towards the control valve. Both spools and boots should be removed at the same time and the two front seals and boots should be replaced before replacing the spools with the back seals. The spools will just slide right in and you just have to replace the two screws attaching each spool. IMPORTANT TO NOTE: Do not at anytime take the clip off of the back of the bottom spool as there are two balls and springs that will go flying if you do. You just have to take the two screws that hold the cover to the control valve off and pull the spool and cover out. Once you have the spools installed it is just a little time to reassemble and replace the fluid. When we did my machine it took about 3 hours with minimal problems except for access to the front boot bolts. Overall a pretty easy job once you know what to do and what not to do. I have been told other Bobcat machines are similar and just might have a few more things you need to remove to provide access room for the spool removal.

Brian

You could have cut the seals sliding them on all the way of the spool.

rnbuck01 said:

You could have cut the seals sliding them on all the way of the spool.

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You are correct you could cut them installing over the spool. But in the end you have to slide one over the spool to get it where it belongs, if you don't want to take the detent assembly apart. One thing that could be done and recommended, that we did not do, would be to put a wrap or two of saran-wrap over the spool to prevent cutting of the seal. once the seal is in place you can just remove the saran-wrap. Lucky for us we did not cut the seal as we have no leaks at this time. Good you brought that up though for someone reading this thread and thinking of doing this job them self.

nobull1 said:

You are correct you could cut them installing over the spool. But in the end you have to slide one over the spool to get it where it belongs, if you don't want to take the detent assembly apart. One thing that could be done and recommended, that we did not do, would be to put a wrap or two of saran-wrap over the spool to prevent cutting of the seal. once the seal is in place you can just remove the saran-wrap. Lucky for us we did not cut the seal as we have no leaks at this time. Good you brought that up though for someone reading this thread and thinking of doing this job them self.

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r u a bobcat tech

rnbuck01 said:

r u a bobcat tech

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I know I must have replaced spool seals on Bobcats at least 100 times or more on many different models and have never cut a seal by sliding it over the length of the spool , take care and go slow and all will be well , I have put a seal in backwards a few times not paying attention and you will know if you did real fast as it flows right out , the way I think about how the seal goes is by looking at the inside ring and have the inside of the v facing the valve as pressure will push the tip of the inside against the spool-----a 1/4 drive 3/16 allen socket and a 1/4 inch ractheting spinner makes this job go easier , if you don't have one a 1/4 drive socket with a piece of an allen wrench cut from a key with a lite tack weld to hold it together works real good as it has a smaller diameter than a allen socket and gets between the wall and the spool caps well , also a Gearwrench ratcheting bit driver is the ultimate tool for those allen bolts , I have used a 1/4 drive air ratchet but find it hard to get in on certain machines ------there are actually 4 balls and 2 springs , but you would never see them unless you dissassemble the centering spring on the end of the spool , but if detent is not working when you go in for a seal job be aware of that second set of balls and springs -----------you got an easy model to do as some machines you have to remove bolts holding the valve in , disconnect a few tubes and cock the valve to get the spool out the back side ---on a couple of models it is possible to grind a little half circle off the top of the plastic fuel tank filler neck and get the spool out , it does effect it any as it is 2 1/2 to 3 inches long and you only take off 3/8 -1/2 "----------another trick on newer machines that have spool lock out solinoids on the spools is to power up the electrical system by turning on the ignition after you have every thing disconnected and you can slide the whole nose off the valve with the solionids still in place which saves the time of taking the both of them in and out -----------care should be take in what seals you put back in as there are quite a few different styles that were used over the years , some are replacement upgrades and will interchange some don't , there were black quad rings , then orange plastic cups that a special installation tool was available to install the spring side seal , then tan , green , purple

rnbuck01 said:

r u a bobcat tech

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Quote: rnbuck01 "r u a bobcat tech"
No I am not a Bobcat tech. For twenty three years I was a air,gas and electric tool service tech. A few years ago I purchased a Bobcat and have been working on most aspects of my machine since. I have access to a few "very" knowledgeable people to help with jobs I would not like to attempt myself the first time. Where I don't do these jobs repetitively I like to take notes in case I might need them in the future. Which brings us back to where I am now on this thread. Probably a whole lot more than you wanted to know

Brian

nobull1 said:

Quote: rnbuck01 "r u a bobcat tech"
No I am not a Bobcat tech. For twenty three years I was a air,gas and electric tool service tech. A few years ago I purchased a Bobcat and have been working on most aspects of my machine since. I have access to a few "very" knowledgeable people to help with jobs I would not like to attempt myself the first time. Where I don't do these jobs repetitively I like to take notes in case I might need them in the future. Which brings us back to where I am now on this thread. Probably a whole lot more than you wanted to know

Brian

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Great post. Have a question on the seals for the lift/tilt spool valves. I pulled out 3 black seals that have a small indentation, but was not "true" V seals. The 4th was orange and was a "V" type seal. Kit as black and orange seals. http://luxjo.supermotors.net/BOBCAT/MAIN%20HYDRAULIC%20VALVE%20SPOOL%20REBUILDS/DCP05903.JPG Also, I did pull off end cap of lift spool. Is there an easy way to get the spring and balls back in?

OX1 said:

Great post. Have a question on the seals for the lift/tilt spool valves. I pulled out 3 black seals that have a small indentation, but was not "true" V seals. The 4th was orange and was a "V" type seal. Kit as black and orange seals. http://luxjo.supermotors.net/BOBCAT/MAIN%20HYDRAULIC%20VALVE%20SPOOL%20REBUILDS/DCP05903.JPG Also, I did pull off end cap of lift spool. Is there an easy way to get the spring and balls back in?

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there were many different seals over the years , some interchangable , some not , the black ones were old school , after black then came some orange ones which were thin and you needed a tool to install them over the spool and not damage them , then cream colored , purple and green , since your is mixed up I'd tell you to give dealer your serial number and see what they recomend ----------there is a pair of pliers to put the spring and balls back in , you can do it with out the tool , this is how I do and I have the pliers in my box but sledom use them , it is hard to explain but here goes , I put the collor in a vise grapping it by the shaft where the e clip goes , it needs to be out the cap to do this , put one bal and the spring into the hole , and cock the bottom ball into thecollar , put the top ball over the spring on top , use a screw driver sideways to push the ball down as you push the spool and it will go right in

OX1 said:

Great post. Have a question on the seals for the lift/tilt spool valves. I pulled out 3 black seals that have a small indentation, but was not "true" V seals. The 4th was orange and was a "V" type seal. Kit as black and orange seals. http://luxjo.supermotors.net/BOBCAT/MAIN%20HYDRAULIC%20VALVE%20SPOOL%20REBUILDS/DCP05903.JPG Also, I did pull off end cap of lift spool. Is there an easy way to get the spring and balls back in?

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Just re-sealed the whole hyd. control valve on my 763c ... The spring and ball were as easy as anything you have ever done..Here is how to do it in 30 seconds... Put the spool valve back into place...place the spring into its hole , place ball into its hole , and hold with a finger or thumb keeping pressure on the first ball and the end of the spring. Then place the other ball into place , keeping pressure on the first ball , and now the second ball. Here's how to get them back in without a worry... Take a pair of channel lock pliers...lightly slide the jaws of the pliers over the balls holding them GENTLY in their place. With the side of the pliers against the control valve housing when you clamp the balls together LIGHTLY...begin to push the spool valve cover over the spool valve into place , while releasing a LITTLE pressure on the pliers... It should slide over the balls and spring like butter.....

fishhunter2 said:

Just re-sealed the whole hyd. control valve on my 763c ... The spring and ball were as easy as anything you have ever done..Here is how to do it in 30 seconds... Put the spool valve back into place...place the spring into its hole , place ball into its hole , and hold with a finger or thumb keeping pressure on the first ball and the end of the spring. Then place the other ball into place , keeping pressure on the first ball , and now the second ball. Here's how to get them back in without a worry... Take a pair of channel lock pliers...lightly slide the jaws of the pliers over the balls holding them GENTLY in their place. With the side of the pliers against the control valve housing when you clamp the balls together LIGHTLY...begin to push the spool valve cover over the spool valve into place , while releasing a LITTLE pressure on the pliers... It should slide over the balls and spring like butter.....

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Thanks for help everyone. Got her all sealed up and back to like new..........errrrrrrrrrrr, well, back to not leaking anyway. Is there away to post pics. I took 40 or more pics of the entire procedure, would like to post up.

OX1 said:

Thanks for help everyone. Got her all sealed up and back to like new..........errrrrrrrrrrr, well, back to not leaking anyway. Is there away to post pics. I took 40 or more pics of the entire procedure, would like to post up.

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I have done it with a heavy duty cable tie before.
For pictures, you need to host them on a site like photobucket. You can then open them and copy/paste to the forum. That or give a link to the photobucket list.

Tazza said:

I have done it with a heavy duty cable tie before.
For pictures, you need to host them on a site like photobucket. You can then open them and copy/paste to the forum. That or give a link to the photobucket list.

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The pics are hosted, here is the link. http://luxjo.supermotors.net/BOBCAT/MAIN HYDRAULIC VALVE SPOOL REBUILDS/ Still don't see any way to post up the pics though.

OX1 said:

The pics are hosted, here is the link. http://luxjo.supermotors.net/BOBCAT/MAIN%20HYDRAULIC%20VALVE%20SPOOL%20REBUILDS/ Still don't see any way to post up the pics though.

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To insert pictures, you right click/copy right click/paste them into the message body.
With som many images, it's possibly best to leave the like you did. Nice job on taking them for us too.