Replacing detent balls on aux. hydraulics

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Tazza

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Has anyone replaced the detent balls for the aux hydraulics on a 743 while the spool was attached to the machine and engine in place?
I was silly, when i re-bult the control block, i didn't touch the detent assembly. It clicked in and held when i tried it on the bench, but that was when there was no oil moving or levers attached.
If its going to be too hard, i think i will just leave it as it is.
 

skidsteer.ca

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Tazz I just know on my 553, I'm going to have to fab up a 90 degree bent set of plyiers or borrow the factory tool, because the detent spring is way to tough to compress in that crampt little space. I may have to pull the valve to resurface the load check valve seat anyhow. I put a new popit in there but the tilt cylinder still leaks down when you first move the spool until you move it enough for the pump to pick up the oil the load check is leaking by. Was hoping it would wear in and seat itself, but it has'nt. That would be the time for me to do it. To bad you missed the opotunity when it was easy, I know mine worked ok the first 20 times I used it too. Then the little detent balls got to small when the rust came off, this should be rebuit any time the valve is out i guess. For $.20 worth of parts, would have been so easy. I feel your pain, done things like that b4. Regards Ken
 

Tazza

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Tazz I just know on my 553, I'm going to have to fab up a 90 degree bent set of plyiers or borrow the factory tool, because the detent spring is way to tough to compress in that crampt little space. I may have to pull the valve to resurface the load check valve seat anyhow. I put a new popit in there but the tilt cylinder still leaks down when you first move the spool until you move it enough for the pump to pick up the oil the load check is leaking by. Was hoping it would wear in and seat itself, but it has'nt. That would be the time for me to do it. To bad you missed the opotunity when it was easy, I know mine worked ok the first 20 times I used it too. Then the little detent balls got to small when the rust came off, this should be rebuit any time the valve is out i guess. For $.20 worth of parts, would have been so easy. I feel your pain, done things like that b4. Regards Ken
Are you sure its the poppet and seat causing the trouble? i remember my old 731 had this exact same problem. I replaced the cylinder seals and exactly the same, but if i pushed my heel back slightly it would stop (with the engine off). The load checks were fine, as in the poppet and seat. The problem was the O rings they used on the load check assembly. The 731 did use a gresson control block, and i'm pretty sure bobcat use their own branded controls now. Worst case, when you pull the control block you can always lap the poppet and seat in.
As for the detent installation tool, i was thinking of using a hose clamp to hold the balls and springs in place. Then slide the back on while moving the clamp forward. Basically like installing pistons in an engine. The clamp will slide along releasing the detent balls into the cap. Its worth a try i guess....
 

skidsteer.ca

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Are you sure its the poppet and seat causing the trouble? i remember my old 731 had this exact same problem. I replaced the cylinder seals and exactly the same, but if i pushed my heel back slightly it would stop (with the engine off). The load checks were fine, as in the poppet and seat. The problem was the O rings they used on the load check assembly. The 731 did use a gresson control block, and i'm pretty sure bobcat use their own branded controls now. Worst case, when you pull the control block you can always lap the poppet and seat in.
As for the detent installation tool, i was thinking of using a hose clamp to hold the balls and springs in place. Then slide the back on while moving the clamp forward. Basically like installing pistons in an engine. The clamp will slide along releasing the detent balls into the cap. Its worth a try i guess....
I hose clamp would work, maybe even a good wire tie, if you have the space for it to slide on the spool ahead of the detent cap. I should check that, I bought new balls but should have got spares too, it was B4 I found this place. My hyd guy told me there was a tool that machined the load check seat flat again, but the valve would have to come out for access reasons. Cylinders will stay put overnite. But dump cyl creeps down (especially with forks on) when you just move the spool a little with you R heel. If you go fast enough its not a problem. It just bugs me that it ain't "right". Have never tried it with the engine off. You do this just to eliminate the pump flow? The original popet had a groove wore .010 to .015 all around the outside, replacing it made 50% improvement of the problem. Only have 25 or so hours on the new popet yet too. Ken
 

Tazza

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I hose clamp would work, maybe even a good wire tie, if you have the space for it to slide on the spool ahead of the detent cap. I should check that, I bought new balls but should have got spares too, it was B4 I found this place. My hyd guy told me there was a tool that machined the load check seat flat again, but the valve would have to come out for access reasons. Cylinders will stay put overnite. But dump cyl creeps down (especially with forks on) when you just move the spool a little with you R heel. If you go fast enough its not a problem. It just bugs me that it ain't "right". Have never tried it with the engine off. You do this just to eliminate the pump flow? The original popet had a groove wore .010 to .015 all around the outside, replacing it made 50% improvement of the problem. Only have 25 or so hours on the new popet yet too. Ken
Thats a fair amount of wear!
I know the tilt cylinder creep all too well, you don't notice it when your running the machine, but when you shut it down you hear it creaping. I'm sure this is just because i have to pull the cylinder apart about 4 times to repair a crack where a hose attached. So i'm sure its just the piston seal.
I shut the machine down to do this so there was no oil moving, so i knew that i wasn't compensating for the lowering of the arms by giving it more oil when i pushed my heel down a bit.
Thats a fair amount of wear! I can't see a problem in making a seat reamer for the valve if needed. One option is if you have the control block out is to give bobcat a call, they would re-machine the seat if they had the gear, which i would think they would, as its their branded control block. Never be afraid to ask them to do little thinks like that, they are happy to help. I know a guy that takes parts in and gets them to assemble it for him and they have no problem with it.
My only concern with replacing the detent balls is the fact that i don't know what the cap is like, if the balls have worn a groove in the housing and replacing the balls may do nothing. But i guess i will deal with that when i need to.
 

Luthor

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Thats a fair amount of wear!
I know the tilt cylinder creep all too well, you don't notice it when your running the machine, but when you shut it down you hear it creaping. I'm sure this is just because i have to pull the cylinder apart about 4 times to repair a crack where a hose attached. So i'm sure its just the piston seal.
I shut the machine down to do this so there was no oil moving, so i knew that i wasn't compensating for the lowering of the arms by giving it more oil when i pushed my heel down a bit.
Thats a fair amount of wear! I can't see a problem in making a seat reamer for the valve if needed. One option is if you have the control block out is to give bobcat a call, they would re-machine the seat if they had the gear, which i would think they would, as its their branded control block. Never be afraid to ask them to do little thinks like that, they are happy to help. I know a guy that takes parts in and gets them to assemble it for him and they have no problem with it.
My only concern with replacing the detent balls is the fact that i don't know what the cap is like, if the balls have worn a groove in the housing and replacing the balls may do nothing. But i guess i will deal with that when i need to.
Yes Tazza, I have done this. You will not be able to use a normal worm drive hose clamp, I had to use a slightly modified plastic ratchet clamp as used on the black poly. pipe for garden and lawn irrigation.
 

Tazza

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Yes Tazza, I have done this. You will not be able to use a normal worm drive hose clamp, I had to use a slightly modified plastic ratchet clamp as used on the black poly. pipe for garden and lawn irrigation.
ahh yes, i can see that working, it also won't scratch anything.
Did you replace them on the machine, or did you have to pull the control block out? As removing the control block is not an option for me, it will involve way too much time and effort to remove it now. I think i stand a chance to do it on the machine, but the engine sure will make it harder. I can pull the engine fairly easily if i really need to, but again thats a last resort. I can see i'm in for alot of swearing and frustration to get it done. Did you also replace the springs? i'm just wondering if i should replace them while i'm there, i think they were about $5 each.
Thanks for the input.
 

Luthor

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ahh yes, i can see that working, it also won't scratch anything.
Did you replace them on the machine, or did you have to pull the control block out? As removing the control block is not an option for me, it will involve way too much time and effort to remove it now. I think i stand a chance to do it on the machine, but the engine sure will make it harder. I can pull the engine fairly easily if i really need to, but again thats a last resort. I can see i'm in for alot of swearing and frustration to get it done. Did you also replace the springs? i'm just wondering if i should replace them while i'm there, i think they were about $5 each.
Thanks for the input.
Tazza, I did mine in situ with the engine in, all I removed was the battery. Old detent balls were badly worn but springs were O.K. You will need a 25mm ratchet clamp machined down to approximately 5mm thick with the outermost part of the locking mechanism removed, some grease, quite a few spare balls and lots of patience but believe me it can be done most likely after a few failed attempts. Good Luck.
 

skidsteer.ca

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Tazza, I did mine in situ with the engine in, all I removed was the battery. Old detent balls were badly worn but springs were O.K. You will need a 25mm ratchet clamp machined down to approximately 5mm thick with the outermost part of the locking mechanism removed, some grease, quite a few spare balls and lots of patience but believe me it can be done most likely after a few failed attempts. Good Luck.
Tazz Cap on my 553 for the detend looked ok, it was just the balls, and the spring is still pretty stiff to. Luthor Are you just refering to a heavy duty wire tie, or is this something much better? Ken
 

Tazza

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Tazz Cap on my 553 for the detend looked ok, it was just the balls, and the spring is still pretty stiff to. Luthor Are you just refering to a heavy duty wire tie, or is this something much better? Ken
I managed to get it on today.
Don't even think about doing it on the machine if you don't have alot of patience, believe me! I was swearing at it ALOT, i started with 4 balls and finished with NONE. The old man had a poke around with a telescopic magnet and managed to find 3 out of 4.
I tried making a compressor out of an old pair of vice grips, but it refused to work properly. I ended up using a meduim sized cable tie, about 4-5mm wide. Don't use the big ones, as you won't be able to slide the case over to release the balls into. Use a nice amount of grease on the spring to hold the balls in place. Start the tie so its like a loop, hook it over the hole with the spring and balls in place and line it so the top ball ends up in the point thats made where the tie goes through its self. pull it down slowly and you will need to poke the ball around a bit as you tighten it up. When in place push the cover over and the tie will slide back releasing the balls, while holding it in place cut the tie off and finish pushing it forward.
Like i said, its NOT fun, but as Luthor said, its can be done! i was all set to make a split ring that i could put over and pull down with a hose clamp, thankfully i didn't need to make that!
 

Luthor

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I managed to get it on today.
Don't even think about doing it on the machine if you don't have alot of patience, believe me! I was swearing at it ALOT, i started with 4 balls and finished with NONE. The old man had a poke around with a telescopic magnet and managed to find 3 out of 4.
I tried making a compressor out of an old pair of vice grips, but it refused to work properly. I ended up using a meduim sized cable tie, about 4-5mm wide. Don't use the big ones, as you won't be able to slide the case over to release the balls into. Use a nice amount of grease on the spring to hold the balls in place. Start the tie so its like a loop, hook it over the hole with the spring and balls in place and line it so the top ball ends up in the point thats made where the tie goes through its self. pull it down slowly and you will need to poke the ball around a bit as you tighten it up. When in place push the cover over and the tie will slide back releasing the balls, while holding it in place cut the tie off and finish pushing it forward.
Like i said, its NOT fun, but as Luthor said, its can be done! i was all set to make a split ring that i could put over and pull down with a hose clamp, thankfully i didn't need to make that!
Good one Tazza, you did well with only 4 balls, I think I started with a bag of 10 or so and ended up with only 2 or 3 left over.
 

Tazza

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Good one Tazza, you did well with only 4 balls, I think I started with a bag of 10 or so and ended up with only 2 or 3 left over.
It was definatly NOT a nice way to spent a saturday morning! After loosing the 4 balls i gave up, my dad came up later in the day and searched around with a magnet for about 30 mins and he managed to find 3. I decided to give it 1 more go in the afternoon and presto! I'm so clad i don't work on these machines for a living!!!!
Its my own fault, i should have replaced them when the control block was on the bench. Its a good lesson learnt......
Every time i goto the dealer and see ppl working on the bobcats, i think “i could do that“ then i remember the torture thats involved in repairs some times....... I remember last time i was there, the parts section is in the same area as the repairs. I was waiting for some parts and you could hear one of the mechanics swearing at one of the machines (i guess thengs weren't going quite rite) all i could think was i have sooo been there.....
 

skidsteer.ca

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It was definatly NOT a nice way to spent a saturday morning! After loosing the 4 balls i gave up, my dad came up later in the day and searched around with a magnet for about 30 mins and he managed to find 3. I decided to give it 1 more go in the afternoon and presto! I'm so clad i don't work on these machines for a living!!!!
Its my own fault, i should have replaced them when the control block was on the bench. Its a good lesson learnt......
Every time i goto the dealer and see ppl working on the bobcats, i think “i could do that“ then i remember the torture thats involved in repairs some times....... I remember last time i was there, the parts section is in the same area as the repairs. I was waiting for some parts and you could hear one of the mechanics swearing at one of the machines (i guess thengs weren't going quite rite) all i could think was i have sooo been there.....
So I guess the rule is, purchase a minimum of 7 spare balls, top up your patience, and wait for the stars to align before begining. Congrats, Tazza and Luthor. There is definitely some satisfaction in the feeling you can wrench with the best of them.
While it may be frustrating to try the same thing several times b4 you suceed, It's also expensive to pay a pro to try the same frustrating thing you are at $60 plus a hour.
Guess I need to get off my soapbox now and get to it.
;) Ken
 
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