New Guy - diagnosis suggestions for 763F

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Greatdaen

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Joined
Dec 12, 2005
Messages
33
I am new to the group and new to skid steers. I am building my own house and bought a used 763F to assist. I grew up running farm equipment and have an engineering/mechanical education, but no experience with bobcats. My machine has a couple of issues I would appreciate suggestions about. It is a 763F with 1900 hours. It has the BOSS system, standard controls, remote front ports, no auxiliary hydraulic pump. I have a service manual for it. I bought the machine from a paving contractor. The story... his CASE broke and he needed a machine ASAP. He bought this one off of a dealer's lot. The CASE got fixed and he preferred it's hand controls over the hand/foot controls on the Bobcat. So I really don't have much of a history on this machine. There is a hydraulic leak. I lifted the cab and as best I can tell it is the trunion seal around the control shaft for the RH swash plate. It looks like in the book this is something a 'weekender' can fix. Is it as straight forward as disassembling the controls, removing the cover plate on the hydro and reversing the process after a new seal? Thanks on that one. When I bought the machine and tried to load it on the trailer it was a real circus act. The machine was hoping and bucking all over the place. Being brand new my plan was to run the machine at idle and just creep on the trailer. I finally decided I was a wreck waiting to happen and had one of the guys from the paving company load it. The first thing he did was to run the throttle up. A little experience has shown me that it behaves much more predictably with the throttle up. Is this expected? At idle the machine is wanting to move around. Now that I have used it some and comfortable with it, there is definitely a fly in the ointment. The hydraulic leak is on the RH side, but the problem seems to be on the LH side. When I start the machine - with throttle at idle - it starts it jumping routine; always the left side acting up. A few times - and this seems to be occurring a little more often now - as it starts, the left side seems to be under a load and it stalls the machine. There is a growling noise while this is occurring and the LH control is jumping around. I have tried to move the control lever a little to find neutral but this is not always successful. If I can get it started and then get the throttle up half or better, it seems to relax. Any ideas on things to check or suggestions on how it is about to suck to be me. Thanks on that one. The BICS system has a fault with the seat - seat light flashes. Even though the machine jumps around, you have to push the traction override to engage things. When I bought it, I thought that was a safety item - wasn't smart enough to know something was broken. Is this a simple squat switch in the coushin? The last issue is the brakes. As said the machine jumps around. It won't move in general because of the BICS. But once overridden, it will move with the brake set or not. I have not removed the inspection plates, but it looks from the manual that the brake is a cogged parking pawl type mechanism. Should it keep the machine from moving? Does the solenoid go bad? Do the gogs break off? Sorry for being so long-winded. I wanted to put all the issues out. Suggestions on any one of them is greatly appreciated. -dch
 

Tazza

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Dec 7, 2004
Messages
16,829
Ok, your first problem of the oil leak i can't help with, i'm not sure what the controls look like on this machine.

Second one of engine speed, ALL skid steer need to be run at 1/2 throttle or more, never move them around at idle they will make a horrible groan or humming/grinding noises and damage the pumps.

As for the BICS saying there is a seat problem, there is a switch that sits under the cab that is attached to the seat rail (well should be under there or in the seat). I cheated on the one a friend has, his seat was rusted out, so i drilled a hole in the seat rail and but a bolt and nut through it so the BISC thought someone was always sitting down, worked a treat.
 

goodtech

Well-known member
Joined
Nov 22, 2005
Messages
112
Well there guy I'm here to tell you your going to have more than a weekend into this machine. the reason the unit is jumping around is that the bushings in the steering are worn and it is not adjusted correctly. If you are going to fix the leak, go by yourself a manual, get ALL the steering bushings. I'm here to tell you once you go to fix this weekender leak, you are going to be swearing, because it is not as easy as it sounds. make sure you have the parts, and 12 pack of beer, and read and understand the manual on how to remove the steering, replace all the bushings, repair your leak, how to re install your steering and adjust your nuetral setting and travel settings. the first time you do it is a coulple day job usually. As for your seat switch bobcat has a by pass kit for that piece of crap it is around 200 dollars but it will save you a bunch of headaches. As for your parking brake, when those soleniods go bad they keep the unit locked up, I would remove the soleniod and look at your clogs and the bar that locks the clogs. What usaully happens when the steering comes out of nuetral people over power the brake and bend parts, usually they bend the bar on the end of the soleniod. If you have any problems with understanding on how to adjust the steering or what parts to replace please let me know, and I will try to get a parts break down for you and highlight all the parts that I usually replace. Good luck you will love this machine once it gets going
 
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Greatdaen

Active member
Joined
Dec 12, 2005
Messages
33
Well there guy I'm here to tell you your going to have more than a weekend into this machine. the reason the unit is jumping around is that the bushings in the steering are worn and it is not adjusted correctly. If you are going to fix the leak, go by yourself a manual, get ALL the steering bushings. I'm here to tell you once you go to fix this weekender leak, you are going to be swearing, because it is not as easy as it sounds. make sure you have the parts, and 12 pack of beer, and read and understand the manual on how to remove the steering, replace all the bushings, repair your leak, how to re install your steering and adjust your nuetral setting and travel settings. the first time you do it is a coulple day job usually. As for your seat switch bobcat has a by pass kit for that piece of crap it is around 200 dollars but it will save you a bunch of headaches. As for your parking brake, when those soleniods go bad they keep the unit locked up, I would remove the soleniod and look at your clogs and the bar that locks the clogs. What usaully happens when the steering comes out of nuetral people over power the brake and bend parts, usually they bend the bar on the end of the soleniod. If you have any problems with understanding on how to adjust the steering or what parts to replace please let me know, and I will try to get a parts break down for you and highlight all the parts that I usually replace. Good luck you will love this machine once it gets going
Thanks for the comments. I do have a service manual so I have the exploded views and general procedures. I am going to do a little exploring under the hood this weekend and see if I can get a little more insite to the issues. I'll let you know what I find. -dch
 

bobbie-g

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Joined
Mar 15, 2004
Messages
577
Thanks for the comments. I do have a service manual so I have the exploded views and general procedures. I am going to do a little exploring under the hood this weekend and see if I can get a little more insite to the issues. I'll let you know what I find. -dch
dch -- The seat switch on my 751 quit working at one point. I removed the seat and disassembled the switch. It appears to be a magnetically activated switch. A magnet moves up and down in a sensor assembly. When the magnet is in the right position, it is detected and an "operator present" or some such signal is sent to the control system. Turned out on mine the magnet was not travelling enough, so we adjusted it with a washer. If it gives any more trouble, I'll just insert the magnet in the sensor and glue it in place so the control system always thinks I'm in the seat. --- Bob
 

nick-osborne

New member
Joined
Jul 17, 2007
Messages
4
dch -- The seat switch on my 751 quit working at one point. I removed the seat and disassembled the switch. It appears to be a magnetically activated switch. A magnet moves up and down in a sensor assembly. When the magnet is in the right position, it is detected and an "operator present" or some such signal is sent to the control system. Turned out on mine the magnet was not travelling enough, so we adjusted it with a washer. If it gives any more trouble, I'll just insert the magnet in the sensor and glue it in place so the control system always thinks I'm in the seat. --- Bob
just wondering if you guys would have the wiring diagrams for the 763f i need the breaks system, back up light and the power wire for the fan switch is died :S and does anyone know why the fuel gauge dont work ? i was told there is a chain oiler on this bobcat but i looked every where and couldnt find one
 

Tazza

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Dec 7, 2004
Messages
16,829
just wondering if you guys would have the wiring diagrams for the 763f i need the breaks system, back up light and the power wire for the fan switch is died :S and does anyone know why the fuel gauge dont work ? i was told there is a chain oiler on this bobcat but i looked every where and couldnt find one
As far as i was aware, the chain runs in an oil bath so there is no "oiler" as such.
From what you describe, i would be looking for a broken power wire or blown fuse. It could even be a bad relay.
For you to loose all those functions it sounds like a common cause. Check your ground connections too.
 

nick-osborne

New member
Joined
Jul 17, 2007
Messages
4
As far as i was aware, the chain runs in an oil bath so there is no "oiler" as such.
From what you describe, i would be looking for a broken power wire or blown fuse. It could even be a bad relay.
For you to loose all those functions it sounds like a common cause. Check your ground connections too.
i got a fan and back up lights working and i found out the breaks lock rod was taking out for some reson :S i still dont got the fuel gauge tho
 

Fishfiles

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Joined
Feb 8, 2007
Messages
1,698
i got a fan and back up lights working and i found out the breaks lock rod was taking out for some reson :S i still dont got the fuel gauge tho
Taking one prob at a time , your jumping around and creeping , the alum pintle arm is loose or worn out inside the square bore from being loose on the steel shaft on top of the sunstrand pump , it's the aluminum looking triangluar shaped piece that connects to the steering bar , classic example of creeping at idle and gets better when reved up , try tighting it up and adjusting the neutral if needed , and it will robally last a while , but new pintles with some locktite is what it's going to eventually need
 

Fishfiles

Well-known member
Joined
Feb 8, 2007
Messages
1,698
Taking one prob at a time , your jumping around and creeping , the alum pintle arm is loose or worn out inside the square bore from being loose on the steel shaft on top of the sunstrand pump , it's the aluminum looking triangluar shaped piece that connects to the steering bar , classic example of creeping at idle and gets better when reved up , try tighting it up and adjusting the neutral if needed , and it will robally last a while , but new pintles with some locktite is what it's going to eventually need
I take it the leak you are talking of is under the pintel lever , when you got it off to replace it , the o rings and back up rings are under the lever , there is a shaft that is pulled out then a collar needs to be removed by carefully pulling it up and out so you can change the orings and backups on it , when you take this apart it will leak oil constantly , if you never did it before if you don't want to make a mess it's better the drain the tank , you can work fast and not drain the tank
 

skidboy

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Joined
Jan 3, 2007
Messages
94
I take it the leak you are talking of is under the pintel lever , when you got it off to replace it , the o rings and back up rings are under the lever , there is a shaft that is pulled out then a collar needs to be removed by carefully pulling it up and out so you can change the orings and backups on it , when you take this apart it will leak oil constantly , if you never did it before if you don't want to make a mess it's better the drain the tank , you can work fast and not drain the tank
Fishfiles,i think that you are assuming a 763 is servo controlled,which if it was the above procedure would be correct.But all 763s are manual controll,and under the aluminium lever is a plate that is held on with 4 bolts.A seal and a square section O RING is needed to fix the leak.As stated above beware as oil will go everywhere.
 
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