Bobcat 600 Sheave questions

[MikeHall]

I just bought a bobcat 600 that had the variable speed unhooked. The hydraulic line is no longer there and the fitting on the valve is capped off now. It sure looks like it has been this way for a very long time. The sheave is complete and I was able to get the first snap ring and cap off as well as the large snap ring holding the whole piston assemble inside the sheave. I have however not been able to get the piston unit to come out of the sheave. I have check and checked again for a possible bur or damage to the boar of the sheave which would cause it to get stuck but I see nothing. What is the trick to getting that whole piston unit pulled out? I suspect that it was unhooked due to a leak or that is what I am hoping so maybe it will be an easy fix. Also, another question which I think I have done my best to address is sealing the Wisconsin manifold to the heads? My manifold is not in the best of shape with a good bit of erosion which will keep the flanges from sealing correctly. I cleaned up all the exhaust mating surfaces and uses a bronze brazing rod to add a little material to the flange then ground it all level with the intake flanges which are in good shape. I believe the manifold will seal well now but is there any tricks to keeping them sealed up over time?

 

[alchemysa]

Welcome to the forum Mikehall.
Member 6brnorma is best qualified regarding the sheave so hopefully he will respond soon.
Regarding the manifold. You should have a round, shallow, cup shaped, gasket in each of the six holes. (4 exhaust, 2 intake). You can see one of these gaskets in the left side of the pic attached. They are comprised of a thin circle of gasket material sandwiched between thin metal.
Mine came as part of a complete gasket set but I'm sure they would be available on their own.
Theres a thread for 610 parts... http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=99315
This guy is a good source for cheap Wisconsin parts. ... Tim At Rock Creek Consulting. Brumbaugh Rd. New Enterprise, Pa. 16664 814-766-3675. Search for Wisconsin engine parts on Ebay and you should find him. Or email at... [email protected]

 

[MikeHall]

Welcome to the forum Mikehall.
Member 6brnorma is best qualified regarding the sheave so hopefully he will respond soon.
Regarding the manifold. You should have a round, shallow, cup shaped, gasket in each of the six holes. (4 exhaust, 2 intake). You can see one of these gaskets in the left side of the pic attached. They are comprised of a thin circle of gasket material sandwiched between thin metal.
Mine came as part of a complete gasket set but I'm sure they would be available on their own.
Theres a thread for 610 parts... http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=99315
This guy is a good source for cheap Wisconsin parts. ... Tim At Rock Creek Consulting. Brumbaugh Rd. New Enterprise, Pa. 16664 814-766-3675. Search for Wisconsin engine parts on Ebay and you should find him. Or email at... [email protected]

Thanks for the post. I have that gasket set but clearly they do not last that long as I have seen many of these engines with black smut around the manifold from leaking. I was not sure if there was anything that could be done to increase longevity of those gaskets. I guess just making sure the manifold is good at tight will do that job. http://s239.photobucket.com/user/Mhall222/library/Bobcat%20M600

 

[MikeHall]

Thanks for the post. I have that gasket set but clearly they do not last that long as I have seen many of these engines with black smut around the manifold from leaking. I was not sure if there was anything that could be done to increase longevity of those gaskets. I guess just making sure the manifold is good at tight will do that job. http://s239.photobucket.com/user/Mhall222/library/Bobcat%20M600

Looking through my manual again I think I see how the piston is removed. After pulling the larger snap ring from behind the outer cap i then put the cap back on with the snap ring on the actual piston shaft and use pry bars behind that outer cap to coax the pistons assembly out. The drawing in the manual through me off a bit and the instructions lack detail but i think this should work .I do need to get another snap ring for the piston as it was broken when i went to remove it.

 

[MikeHall]

Looking through my manual again I think I see how the piston is removed. After pulling the larger snap ring from behind the outer cap i then put the cap back on with the snap ring on the actual piston shaft and use pry bars behind that outer cap to coax the pistons assembly out. The drawing in the manual through me off a bit and the instructions lack detail but i think this should work .I do need to get another snap ring for the piston as it was broken when i went to remove it.

Well, I got it all apart and found that the floating seal is totally destroyed, the rest of the parts look ok other than the bearings which are feeling rough. Anyone know where I can get some parts to fix this piston setup without spending 1/3 what I paid for the whole dang loader? I called bobcat of ATL and that one little floating seal was almost $50. Surely there is a generic floating seal that could be used or did bobcat design and have made its own seals?

 

[6brnorma]

Well, I got it all apart and found that the floating seal is totally destroyed, the rest of the parts look ok other than the bearings which are feeling rough. Anyone know where I can get some parts to fix this piston setup without spending 1/3 what I paid for the whole dang loader? I called bobcat of ATL and that one little floating seal was almost $50. Surely there is a generic floating seal that could be used or did bobcat design and have made its own seals?

Welcome Mike…….Parts prices vary considerably from one dealership to another…….also their shipping charges so try several before you place an order. I have had good luck with a dealership: Niemuth Implement (715)678-2271….their prices are consistently reasonable and shipping is fair. If you are going to rebuild the VS Sheave there are several parts you should replace (and have on hand). The "floating seal" …. I believe you are talking about pt#6516301 …. last I paid was $25.00…fragile, be careful when rebuilding the assembly or you will break it. I have never found it anywhere but Bobcat. You should also have spare of ….. lock ring pt#1310052, lock ring pt#6515571, lock ring pt#1319170, O-ring pt#25K-20005, O-ring pt#58K-325, O-ring pt#58K-216, wiper seal pt#6515886. A couple to several of each of these will not amount to any sort of investment at all. Absolutely replace the bearings….(price on them has gone way up…$35.00) as well as all O-rings and snap rings. Be very careful with the swivel pt#6516304 as the price on them has jumped to $125.00 each……DO NOT hammer on it to remove bearings, use a small arbor press….damage that machined end and you WILL be buying another one. Again, caution must be used when reassembling the assembly. Use emery cloth to remove burrs from lock ring grooves prior to inserting the shaft back into the sheave, oil all O-rings and use 1 1/4 in PVC to drive shaft back in place…..do not use anything metal to strike the brass gland. Any questions….just ask.

 

[MikeHall]

Welcome Mike…….Parts prices vary considerably from one dealership to another…….also their shipping charges so try several before you place an order. I have had good luck with a dealership: Niemuth Implement (715)678-2271….their prices are consistently reasonable and shipping is fair. If you are going to rebuild the VS Sheave there are several parts you should replace (and have on hand). The "floating seal" …. I believe you are talking about pt#6516301 …. last I paid was $25.00…fragile, be careful when rebuilding the assembly or you will break it. I have never found it anywhere but Bobcat. You should also have spare of ….. lock ring pt#1310052, lock ring pt#6515571, lock ring pt#1319170, O-ring pt#25K-20005, O-ring pt#58K-325, O-ring pt#58K-216, wiper seal pt#6515886. A couple to several of each of these will not amount to any sort of investment at all. Absolutely replace the bearings….(price on them has gone way up…$35.00) as well as all O-rings and snap rings. Be very careful with the swivel pt#6516304 as the price on them has jumped to $125.00 each……DO NOT hammer on it to remove bearings, use a small arbor press….damage that machined end and you WILL be buying another one. Again, caution must be used when reassembling the assembly. Use emery cloth to remove burrs from lock ring grooves prior to inserting the shaft back into the sheave, oil all O-rings and use 1 1/4 in PVC to drive shaft back in place…..do not use anything metal to strike the brass gland. Any questions….just ask.

Thank you for the info and you are exactly right about dealer pricing as I have gotten prices that vary greatly. I think I may replace the entire piston assembly just to be sure it is leak free. My unit does have a little damage to the shaft part of the piston and although it may not cause an issue it may be better to just replace the whole unit. I have no way to post pictures on here otherwise I would post some of the damage which may or may not be an issue. BTW, the entire piston unit is $305 from the dealer you suggested which is $99 less than the local Atlanta dealer. Thanks Mike

 

[alchemysa]

Thank you for the info and you are exactly right about dealer pricing as I have gotten prices that vary greatly. I think I may replace the entire piston assembly just to be sure it is leak free. My unit does have a little damage to the shaft part of the piston and although it may not cause an issue it may be better to just replace the whole unit. I have no way to post pictures on here otherwise I would post some of the damage which may or may not be an issue. BTW, the entire piston unit is $305 from the dealer you suggested which is $99 less than the local Atlanta dealer. Thanks Mike

To post pics go to the website Tinypics, upload your pic, then copy the html link into your post. It only takes a minute, its much faster and easier than photobucket.

 

[MikeHall]

To post pics go to the website Tinypics, upload your pic, then copy the html link into your post. It only takes a minute, its much faster and easier than photobucket.

Testing to see if tinpics works.

 

[Tazza]

Testing to see if tinpics works.

As photobucket has screwed everyone over, looks like i'm moving to tinypics too

 

[MikeHall]

As photobucket has screwed everyone over, looks like i'm moving to tinypics too

Yeah I was not away that photobucket had changed their setup for using the HTML linked imagines. Oh well no big deal. I have been working the bobcat a couple of hours the past few days. Everything seemed to be working just fine, drive clutches seem to engage well with the right side only slightly stronger. The hydraulics seem to work as they should with good power to where it would even lug the motor down when lifting heavy. Today however i changed the engine oil, added an oil pressure gauge and a new ignition switch and all of the sudden I have no hydraulics at all. Well they will move just a little if i hold the pedal down for a while but for the most part there are no hydraulics now. What on earth could have happened? From working just fine to darn near nothing. Time to start trouble shooting this now I guess. Any ideas? Here is a short vid of me messing around with some roots I started digging up yesterday. https://www.youtube.com/watch?v=vt18xlcyQTw&t=207s

 

[alchemysa]

Yeah I was not away that photobucket had changed their setup for using the HTML linked imagines. Oh well no big deal. I have been working the bobcat a couple of hours the past few days. Everything seemed to be working just fine, drive clutches seem to engage well with the right side only slightly stronger. The hydraulics seem to work as they should with good power to where it would even lug the motor down when lifting heavy. Today however i changed the engine oil, added an oil pressure gauge and a new ignition switch and all of the sudden I have no hydraulics at all. Well they will move just a little if i hold the pedal down for a while but for the most part there are no hydraulics now. What on earth could have happened? From working just fine to darn near nothing. Time to start trouble shooting this now I guess. Any ideas? Here is a short vid of me messing around with some roots I started digging up yesterday. https://www.youtube.com/watch?v=vt18xlcyQTw&t=207s

Double check the oil level in the chain cases. You could have lost a bit yesterday. Just a half inch drop can be the difference between working well and not working at all.
Good video. I note your oil filter is very high. That might be a good thing to maintain pressure at the internal oil spray jets.

 

[MikeHall]

Double check the oil level in the chain cases. You could have lost a bit yesterday. Just a half inch drop can be the difference between working well and not working at all.
Good video. I note your oil filter is very high. That might be a good thing to maintain pressure at the internal oil spray jets.

oil is running out top plug so oil level can not be the issue. I have no clue. It was working totally fine, parked it, change the engine oil, installed a new oil pressure gauge and got back on it to go do a little more messing around and hydraulics would not work. If you hold the pedal down for like a minute i can get a little movement but its very jerky. The oil filter was located there when i got the loader. I was not sure why they mounted it so high but it sure is easy to get to. On with trying to figure out the issue.

 

[6brnorma]

oil is running out top plug so oil level can not be the issue. I have no clue. It was working totally fine, parked it, change the engine oil, installed a new oil pressure gauge and got back on it to go do a little more messing around and hydraulics would not work. If you hold the pedal down for like a minute i can get a little movement but its very jerky. The oil filter was located there when i got the loader. I was not sure why they mounted it so high but it sure is easy to get to. On with trying to figure out the issue.

I would first double check that all pedals are in the neutral position. It also appeared in your video that you have an auxiliary valve…..be sure all levers on it are in the neutral position also. Check from below that no valve spool is stuck in an open position. Double check that the 'coupler' at the pump is functioning.

 

[MikeHall]

I would first double check that all pedals are in the neutral position. It also appeared in your video that you have an auxiliary valve…..be sure all levers on it are in the neutral position also. Check from below that no valve spool is stuck in an open position. Double check that the 'coupler' at the pump is functioning.

Well, I have no clue where to go with this thing as of now. I have removed the floors to clean the valves and make sure nothing was jammed open. Everything looks great. The only thing I know is that clearly the hydraulic pump is working as I can nearly stall the engine by holding one of the valves open even after the movement limits have been reached. It just takes a very long time to get to the limits yet it seems to improve a touch then all the sudden stop responding all together. This is very odd to me. It has to be something simple but I sure dont know what it is. I am correct in my thinking that if the hydro pump is able to stall the engine then it is pumping the fluid correctly right?

 

[alchemysa]

Well, I have no clue where to go with this thing as of now. I have removed the floors to clean the valves and make sure nothing was jammed open. Everything looks great. The only thing I know is that clearly the hydraulic pump is working as I can nearly stall the engine by holding one of the valves open even after the movement limits have been reached. It just takes a very long time to get to the limits yet it seems to improve a touch then all the sudden stop responding all together. This is very odd to me. It has to be something simple but I sure dont know what it is. I am correct in my thinking that if the hydro pump is able to stall the engine then it is pumping the fluid correctly right?

Heres a diagram of the basic hydraulic system. (You have some additional plumbing).
Its a continuously circulating system. Reservoir>Filter>Pump> Main Control block>Sheave Control valve>Back to Pump. (Some of it will be diverted to oil the chains).
Basically the oil continually flows in a big circle through all the valves until you activate a lever. Then, when a cylinder reaches its limit the main relief valve kicks in until you centre the valve.
If the main relief valve is stuck open either because its faulty, or a control valve is not centred, then the oil will just keep circulating back to the pump and you'll have no pressure in the system. (I thinks thats what happens).
You checked the valves under the floor. Have you tried playing around with the sheave control lever?
Do you have the repair and parts books? The last post in this thread has links to them. All free.... http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=99315

 

[6brnorma]

Heres a diagram of the basic hydraulic system. (You have some additional plumbing).
Its a continuously circulating system. Reservoir>Filter>Pump> Main Control block>Sheave Control valve>Back to Pump. (Some of it will be diverted to oil the chains).
Basically the oil continually flows in a big circle through all the valves until you activate a lever. Then, when a cylinder reaches its limit the main relief valve kicks in until you centre the valve.
If the main relief valve is stuck open either because its faulty, or a control valve is not centred, then the oil will just keep circulating back to the pump and you'll have no pressure in the system. (I thinks thats what happens).
You checked the valves under the floor. Have you tried playing around with the sheave control lever?
Do you have the repair and parts books? The last post in this thread has links to them. All free.... http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=99315

Sure seems like it would be something simple since you only did an oil change and it suddenly quits working. I've always been lucky (in a way) …all of my hydraulic problems have been obvious. I've never had a relief valve fail…..maybe that's what you're looking at. The hardest one I've ever had was an internal crack in the main valve …. that took a professional hydro man to spot that one for me. I'm just not that good with hydraulics.

 

[MikeHall]

Sure seems like it would be something simple since you only did an oil change and it suddenly quits working. I've always been lucky (in a way) …all of my hydraulic problems have been obvious. I've never had a relief valve fail…..maybe that's what you're looking at. The hardest one I've ever had was an internal crack in the main valve …. that took a professional hydro man to spot that one for me. I'm just not that good with hydraulics.

Thanks for the details on the hydraulic system. I do have a very nice set of manuals which i have found to be very helpful and by far the best manuals of any machine I have owned. I messed with this thing until almost midnight and did not figure anything out. Its like there is a little bit of movement or very slow movement of the hydraulics then all of the sudden nothing for minutes until i guess a little more pressure builds. I have played with all of the valves including the variable speed valve and nothing makes any difference. The only thing that I can think of that I did other than change the oil before finding the hydraulics did not work anymore was mess with a large quick connector on the aux valve. It is two lines from that aux valve looping back into one another. At the time I had messed with it, I was not able to get it apart but last night i was able to finally get it apart and then put back together. Is it possible that me using hydraulic oil is the issue? I was not away that these things needed motor oil for the hydraulic system and I put about 5 gallons of regular hydraulic fluid in the system. When i was in the chain case the oil was redish so i thought this is hydraulic oil, maybe thats the issue? I am going to drain the system and change it all over but first i would like to figure out the issue before i spend $150 on motor oil.

 

[alchemysa]

Thanks for the details on the hydraulic system. I do have a very nice set of manuals which i have found to be very helpful and by far the best manuals of any machine I have owned. I messed with this thing until almost midnight and did not figure anything out. Its like there is a little bit of movement or very slow movement of the hydraulics then all of the sudden nothing for minutes until i guess a little more pressure builds. I have played with all of the valves including the variable speed valve and nothing makes any difference. The only thing that I can think of that I did other than change the oil before finding the hydraulics did not work anymore was mess with a large quick connector on the aux valve. It is two lines from that aux valve looping back into one another. At the time I had messed with it, I was not able to get it apart but last night i was able to finally get it apart and then put back together. Is it possible that me using hydraulic oil is the issue? I was not away that these things needed motor oil for the hydraulic system and I put about 5 gallons of regular hydraulic fluid in the system. When i was in the chain case the oil was redish so i thought this is hydraulic oil, maybe thats the issue? I am going to drain the system and change it all over but first i would like to figure out the issue before i spend $150 on motor oil.

I really don't think the oil type is the problem. I wouldn't bother changing it.
I'd say that quick connect setup is your problem. Having a q.c. hose looping back onto itself doesn't sound right to me. Have you tried removing the hose completely?