863 will not move

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t-man

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Jan 9, 2006
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i have an 863. i just overhauled the hydostatic pump reinstaled it in the machine.everything worked at firts now it will not move. the right wheel will move very slow when the machine is up on jack stands.the left wheel does not move at all.one other thing i noticed is that without the machine running you can turn the right side wheels by hand and the left side will not budge unles you crack open the hoses on the drive motor.any help would be great.
 

Tazza

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Ok, i'm not trying to be rude so hang in there, we need a bit more information on this.
What did you replace in the pump? was there a problem before you cracked it open? I'm sure you did, but did you check the steering linkages?
Are there any unusual sounds?
The hydro motors when full of oil should not be able to be moved by hand, so that is totally normal, if you remove a hose you will be able to move them.
Even if you connected the hoses to the motors backwards they would still work, just backwards so that theory is out.
Is the oil foamy when you try to move it and open a hose to one of the motors at all (with the machine off)? Don't try to do this with the machine running, the hydro pump can deliver over 5,000 PSI which is more than enough to do some serious damage to you.
 

t-man

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Ok, i'm not trying to be rude so hang in there, we need a bit more information on this.
What did you replace in the pump? was there a problem before you cracked it open? I'm sure you did, but did you check the steering linkages?
Are there any unusual sounds?
The hydro motors when full of oil should not be able to be moved by hand, so that is totally normal, if you remove a hose you will be able to move them.
Even if you connected the hoses to the motors backwards they would still work, just backwards so that theory is out.
Is the oil foamy when you try to move it and open a hose to one of the motors at all (with the machine off)? Don't try to do this with the machine running, the hydro pump can deliver over 5,000 PSI which is more than enough to do some serious damage to you.
i repaired the hydro because the machine caught fire. i just rplaced the seals and o rings and the main pressure relief valve spring. the steering linkage is ok and it all moves. the oil is foamy when the machine is running in the tank.when i crack the line and move it the hose spits and hisses when i move the wheels. is there still air in the syaytem and if so how do i get it out. i have ran the machine for some time and nothing has changed? thank you for your help.
 

Tazza

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i repaired the hydro because the machine caught fire. i just rplaced the seals and o rings and the main pressure relief valve spring. the steering linkage is ok and it all moves. the oil is foamy when the machine is running in the tank.when i crack the line and move it the hose spits and hisses when i move the wheels. is there still air in the syaytem and if so how do i get it out. i have ran the machine for some time and nothing has changed? thank you for your help.
ahh, so you didn't exactly crack the pump open. Well, the system is self bleeding, so it should get all the air out of the system on its own. Generally what you do is run the maching for a few minutes then stop and let it rest for an hr or so for the oil to settle then repeat as many times as needed.
The only other thing i can think of is you may have a problem with the high pressure valves in the pump not holding to give you drive. You did replace the burnt hoses too? as when they burn they will deposit chunks of burnt hose to the hydro system that can lodge almost anywhere.
The other thing it could be is a filter, as the oil goes foamy when its starving for oil.
If that still fails, Goodtech will no doubt have the answer.
 

goodtech

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ahh, so you didn't exactly crack the pump open. Well, the system is self bleeding, so it should get all the air out of the system on its own. Generally what you do is run the maching for a few minutes then stop and let it rest for an hr or so for the oil to settle then repeat as many times as needed.
The only other thing i can think of is you may have a problem with the high pressure valves in the pump not holding to give you drive. You did replace the burnt hoses too? as when they burn they will deposit chunks of burnt hose to the hydro system that can lodge almost anywhere.
The other thing it could be is a filter, as the oil goes foamy when its starving for oil.
If that still fails, Goodtech will no doubt have the answer.
When this machine caught on fire how hot did it get? If it go t hot enough it may of weakened the charge pressure spring. When changing the seals did you have the charge pressure valve out? if you did did you loose any of the shims. How far did you tear into the hydrostat? The unit may be air locked but I think you have a bigger problem than that. So let me know exactly what you did to the hydrostat, what seals where replaced, what shafts you had out, and how far you had this thing apart so I can get you headed in a direction
 

t-man

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When this machine caught on fire how hot did it get? If it go t hot enough it may of weakened the charge pressure spring. When changing the seals did you have the charge pressure valve out? if you did did you loose any of the shims. How far did you tear into the hydrostat? The unit may be air locked but I think you have a bigger problem than that. So let me know exactly what you did to the hydrostat, what seals where replaced, what shafts you had out, and how far you had this thing apart so I can get you headed in a direction
i had the whole pump apart.everything went back together just great and just as the manual said.after i put it back in the machine it moved back and forth. then the trans. light flashed on and off a few times every thing seemed ok. then the trans. light came on and atayed on. that is where i am at now.i did not have the bics system functioning properly at that time but the brake solinoid was removed.does the bics solinoid/valve on the control valve have anything to do with the drive? if so you may be right that it is air locked.one other thing can you put the setent balls back in the lift spool with out the special tool? thanks i keep you up to date with what is going on.
 

Tazza

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i had the whole pump apart.everything went back together just great and just as the manual said.after i put it back in the machine it moved back and forth. then the trans. light flashed on and off a few times every thing seemed ok. then the trans. light came on and atayed on. that is where i am at now.i did not have the bics system functioning properly at that time but the brake solinoid was removed.does the bics solinoid/valve on the control valve have anything to do with the drive? if so you may be right that it is air locked.one other thing can you put the setent balls back in the lift spool with out the special tool? thanks i keep you up to date with what is going on.
The trans light comes on when it detects that the charge pressure going to the pump is not high enough, usually when the oil is foamy from air in the system. As goodtech said eariler, i would check the charge pressure poppet in the pump, this controlls the charge pressure its a good place to start.
I don't think the BICS actually locks you out of the drive other than my not releasing the park brake, but i don't know much about BICS machines, this is one for Goodtech.
I'm pretty sure the detent balls will go back in without a special tool, just use dobs of grease to hold the balls so they don't fall out. I'm pretty sure it will be a pain to get them back in, i have to do it myself in a few days.
 

t-man

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The trans light comes on when it detects that the charge pressure going to the pump is not high enough, usually when the oil is foamy from air in the system. As goodtech said eariler, i would check the charge pressure poppet in the pump, this controlls the charge pressure its a good place to start.
I don't think the BICS actually locks you out of the drive other than my not releasing the park brake, but i don't know much about BICS machines, this is one for Goodtech.
I'm pretty sure the detent balls will go back in without a special tool, just use dobs of grease to hold the balls so they don't fall out. I'm pretty sure it will be a pain to get them back in, i have to do it myself in a few days.
i have found the problem.i removed the case drain fitting from the left half of the pump and the worst!! a lot of brass shavings and a large piece of brass.so i will let you know what i find. does anyone have a hydro pump for an 863? thanks
 

Tazza

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i have found the problem.i removed the case drain fitting from the left half of the pump and the worst!! a lot of brass shavings and a large piece of brass.so i will let you know what i find. does anyone have a hydro pump for an 863? thanks
EEK
The problem is all those shavings.... I'm not sure if ALL the case drain goes through the filter or not, if not you may need to purge all your lines and clean out your cylinders and motors...
The brass is probably your swash plate, you can replace these with your rotating group if you have only killed one side of your pump, but they are a tad pricy! See what Goodtech comes up with.
 

goodtech

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Nov 22, 2005
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EEK
The problem is all those shavings.... I'm not sure if ALL the case drain goes through the filter or not, if not you may need to purge all your lines and clean out your cylinders and motors...
The brass is probably your swash plate, you can replace these with your rotating group if you have only killed one side of your pump, but they are a tad pricy! See what Goodtech comes up with.
Ouch that is not a good thing at all. The case drain filters should catch most of the brass, but now it is probally in your drive motors also. The best thing to do is replace the hydrostat, and the hydraulic pump. Guys these hydrostats are pretty much bullet proof, the only failure that I have scene of them is people breaking them open because they think that there is something wrong inside of them, 95% of the time it is something stupid like a relieve sticking or something to that affect that can be fixed by not breaking them open. So please if they are working leave them together. As for your brake your bics system does lock it. Good luck
 

goodtech

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i had the whole pump apart.everything went back together just great and just as the manual said.after i put it back in the machine it moved back and forth. then the trans. light flashed on and off a few times every thing seemed ok. then the trans. light came on and atayed on. that is where i am at now.i did not have the bics system functioning properly at that time but the brake solinoid was removed.does the bics solinoid/valve on the control valve have anything to do with the drive? if so you may be right that it is air locked.one other thing can you put the setent balls back in the lift spool with out the special tool? thanks i keep you up to date with what is going on.
You can also put that those balls in without the special tool. if you need to go buy them just buy a pack of ten because by the time you are done you will loose a couple. Your bics valve on your control valve has nothing to with your drive, it just locks out your control valve, I'm miss read it on the last posting
 
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