couple issues you may be able to help with

[dball]

This is my first post but I've been reading for awhile. I just used some advice here to replace the fuel pickup tube on my 763. By the way, if you do replace the pickup tube, replace the bushing/grommet.
I kept trying to get the original back in and it wouldn't go. I guess it just hardened over time because I bought the new bushing and it was much softer and popped in much easier (not easy, but only took a few minutes).
Anyway, I am no where close to a mechanic. I work on computers for a living and have a little land that I've been working on myself so a year ago I bought a used 763 with a trailer for $7500. Has about 3700 hours on it.
Everything was working great for the last 11 months or so and now I've run into some problems. I had a hydraulic leak that started up a month or two ago. Tracked it down to a control valve and decided not to attempt the job myself.
Found a guy here that did for me for a very fair price. Everything seemed ok with that. Seems to pull a little more one way now than it did before but no leak.
I then decided to take my machine into the bobcat dealer and get some maintenance done. I got the oil changed, replaced the hydraulic fluid because it wasn't bobcat fluid, changed two belts, programmed the computer because it was throwing a generic code which indicating programming needed. $900 later and I feel like the machine is louder and I have the following issues: -
When I lower the bucket (not tilt) it goes very slow but seems to have full power just very slow. Something just feels odd with the pedal but it could just be because the bucket is going so slow and I never had to pay attention to it before. Everything else (raising and tilting) is fine. -
The emergency brake is not working. The first I found out about this was at the bobcat dealership. I thought it worked ok before but did occasionally notice some issues with it.
Every so often I'd have to either specifically back up or go forward after turning off the brake to get it to move the other direction. A couple times I accidentally forgot to take off the brake and started to go and it didn't sound good but would move a little. Now it doesn't work at all. -
There also seems to be a loose chain sound sometimes when the bucket is all the way down and I drive. I move it up a little and the sound goes away. I would appreciate any advice on dealing with these issues. Thank you in advance for your time.

 

[dball]

Did some more testing and both up and down with the left pedal are slow. I am still able to lift the bobcat way off the ground but it could be weaker. I'm not sure. Also, it wasn't the whole control valve but a spool or something like that was replaced. Could that be the problem? I appreciate any guidance on this.

 

[skidsteer.ca]

I then decided to take my machine into the bobcat dealer and get some maintenance done. I got the oil changed, replaced the hydraulic fluid because it wasn't bobcat fluid,
10/30 motor oil is all your loader needs, but a hyd oil change every 1000 is a good idea, as is changing the chain case oil
changed two belts, programmed the computer because it was throwing a generic code which indicating programming needed. $900 later and I feel like the machine is louder and I have the following issues: -
When I lower the bucket (not tilt) it goes very slow but seems to have full power just very slow. Something just feels odd with the pedal but it could just be because the bucket is going so slow and I never had to pay attention to it before.
Your boom will go down slow if you push the push the pedal down fully as the bucket goes into float mode, there should be a still spot on the pedals travel just before it hit this mode and it should stay stuck down once you go past that point requiring a push with your heel to release. However it is common for the detent to quit working on higher hour machines and the stiff spot you should feel to be gone, parts are cheap and are in the hyd valve if your want it fixed but no harm in leaving it,
Everything else (raising and tilting) is fine. -
The emergency brake is not working. The first I found out about this was at the bobcat dealership. I thought it worked ok before but did occasionally notice some issues with it. Every so often I'd have to either specifically back up or go forward after turning off the brake to get it to move the other direction.
Totally normal, if there is pressure on the park brake you may have to drive the opposite diretion b4 the brake releases. If the click you hear is kinda quiet then it is likely still on.
A couple times I accidentally forgot to take off the brake and started to go and it didn't sound good but would move a little.
Now it doesn't work at all. -
How so? you no longer hear a click? You hear a click but it won't release?
The most common compliant is that it stays on, caused by a bad coil or relay. Or that it comes on while driving causing a sudden stop. Caused by a loose conection.
There also seems to be a loose chain sound sometimes when the bucket is all the way down and I drive. I move it up a little and the sound goes away.
Likely the boom stop making contact with the front of the machine when the boom is fully down.
The only chains are roller ones. Ones to each wheel. There tension can be check by jacking the machine up and rolling the wheel ahead and back. If they are tight the tire tread area should only move a inch or so, if the tire turns 3“ plus it is times to think about new chains.
Also while you have it jacked up see if you can push the tire sideways in and out of the machine to see how your wheel bearing are. They should have no play although a .100“ may exist by 3700 hours.
I would appreciate any advice on dealing with these issues. Thank you in advance for your time.
No problem, please go into your profile and put a check in the box beside “use html editor” and you will have paragraphs in your post.
Skidsteer

 

[dball]

I then decided to take my machine into the bobcat dealer and get some maintenance done. I got the oil changed, replaced the hydraulic fluid because it wasn't bobcat fluid,
10/30 motor oil is all your loader needs, but a hyd oil change every 1000 is a good idea, as is changing the chain case oil
changed two belts, programmed the computer because it was throwing a generic code which indicating programming needed. $900 later and I feel like the machine is louder and I have the following issues: -
When I lower the bucket (not tilt) it goes very slow but seems to have full power just very slow. Something just feels odd with the pedal but it could just be because the bucket is going so slow and I never had to pay attention to it before.
Your boom will go down slow if you push the push the pedal down fully as the bucket goes into float mode, there should be a still spot on the pedals travel just before it hit this mode and it should stay stuck down once you go past that point requiring a push with your heel to release. However it is common for the detent to quit working on higher hour machines and the stiff spot you should feel to be gone, parts are cheap and are in the hyd valve if your want it fixed but no harm in leaving it,
Everything else (raising and tilting) is fine. -
The emergency brake is not working. The first I found out about this was at the bobcat dealership. I thought it worked ok before but did occasionally notice some issues with it. Every so often I'd have to either specifically back up or go forward after turning off the brake to get it to move the other direction.
Totally normal, if there is pressure on the park brake you may have to drive the opposite diretion b4 the brake releases. If the click you hear is kinda quiet then it is likely still on.
A couple times I accidentally forgot to take off the brake and started to go and it didn't sound good but would move a little.
Now it doesn't work at all. -
How so? you no longer hear a click? You hear a click but it won't release?
The most common compliant is that it stays on, caused by a bad coil or relay. Or that it comes on while driving causing a sudden stop. Caused by a loose conection.
There also seems to be a loose chain sound sometimes when the bucket is all the way down and I drive. I move it up a little and the sound goes away.
Likely the boom stop making contact with the front of the machine when the boom is fully down.
The only chains are roller ones. Ones to each wheel. There tension can be check by jacking the machine up and rolling the wheel ahead and back. If they are tight the tire tread area should only move a inch or so, if the tire turns 3“ plus it is times to think about new chains.
Also while you have it jacked up see if you can push the tire sideways in and out of the machine to see how your wheel bearing are. They should have no play although a .100“ may exist by 3700 hours.
I would appreciate any advice on dealing with these issues. Thank you in advance for your time.
No problem, please go into your profile and put a check in the box beside “use html editor” and you will have paragraphs in your post.
Skidsteer

skidsteer, thank you for your reply. Here's some more info. -Float mode still works. I push the pedal to the stop before it enters float mode and it's just slow whether I go up or down. The right pedal seems to be ok still. -I checked the hydro fluid which was ok. Opened the cab and the rear door and didn't see any signs of leaks anywhere either. -I was assuming the parking brake didn't work because when I put it on the bobcat will still move to the left. It's been pulling more to the left lately then it used to. I'll jiggle the handles a little and it will stop moving. I tried to turn on the html editing and it wouldn't let me reply after that. I turned it off and was able to reply. I'll try again later. Thanks again for the help!!

 

[dball]

skidsteer, thank you for your reply. Here's some more info. -Float mode still works. I push the pedal to the stop before it enters float mode and it's just slow whether I go up or down. The right pedal seems to be ok still. -I checked the hydro fluid which was ok. Opened the cab and the rear door and didn't see any signs of leaks anywhere either. -I was assuming the parking brake didn't work because when I put it on the bobcat will still move to the left. It's been pulling more to the left lately then it used to. I'll jiggle the handles a little and it will stop moving. I tried to turn on the html editing and it wouldn't let me reply after that. I turned it off and was able to reply. I'll try again later. Thanks again for the help!!

Ok, I was trying to use my bobcat today and the up and down has definitely lost quite bit of power. It goes down very slow and will lift the bobcat off the ground but it takes a good 10 seconds to get it a foot off the ground. Now when I go up it goes really slow and when stop going up the hydraulics seem to jump a little. Any ideas? I'm sure it will be something expensive but hoping there is something simple and/or cheap I can try. Thanks for your help.

 

[Tazza]

Ok, I was trying to use my bobcat today and the up and down has definitely lost quite bit of power. It goes down very slow and will lift the bobcat off the ground but it takes a good 10 seconds to get it a foot off the ground. Now when I go up it goes really slow and when stop going up the hydraulics seem to jump a little. Any ideas? I'm sure it will be something expensive but hoping there is something simple and/or cheap I can try. Thanks for your help.

I wonder if your aux hydraulics may be stuck on? if they are, it causes a loss of power and hydraulic speed.

 

[dball]

I wonder if your aux hydraulics may be stuck on? if they are, it causes a loss of power and hydraulic speed.

I hooked up a backhoe attachment I just got and am able to turn on and off the aux hydraulics for it. If you can think of anything else to check I would greatly appreciate it.

 

[skidsteer.ca]

I hooked up a backhoe attachment I just got and am able to turn on and off the aux hydraulics for it. If you can think of anything else to check I would greatly appreciate it.

Hook at least a 3000 psi guage to the front coupler and activate the the flow to test where you hydraulic pressure is at. Both at a idle rpm and with the engine 1/2 throttle.
You should get 2500 psi in both cases.
It could be a bad relief valve causing a low pressure problem. not too expensive
Could be a bad pump causing a low pressure problem. @ $500 to $700
You have checked your foot pedal linkages to be sure they are fully stoking the valve spool. If you are getting into float mode it sounds like they are getting the full down stroke at least.
Does your boom leak down if you leave it in the air for 30 mins? You could have a bad cylinder seal too but it would have to be really bad to not lift the front of the machine. You would likely have noticed the boom drop when the pedal is in hold (center) position
Ken

 

[dball]

Hook at least a 3000 psi guage to the front coupler and activate the the flow to test where you hydraulic pressure is at. Both at a idle rpm and with the engine 1/2 throttle.
You should get 2500 psi in both cases.
It could be a bad relief valve causing a low pressure problem. not too expensive
Could be a bad pump causing a low pressure problem. @ $500 to $700
You have checked your foot pedal linkages to be sure they are fully stoking the valve spool. If you are getting into float mode it sounds like they are getting the full down stroke at least.
Does your boom leak down if you leave it in the air for 30 mins? You could have a bad cylinder seal too but it would have to be really bad to not lift the front of the machine. You would likely have noticed the boom drop when the pedal is in hold (center) position
Ken

Ken, I will try out your suggestions and post back. Thanks for your time. Doug

 

[dball]

Hook at least a 3000 psi guage to the front coupler and activate the the flow to test where you hydraulic pressure is at. Both at a idle rpm and with the engine 1/2 throttle.
You should get 2500 psi in both cases.
It could be a bad relief valve causing a low pressure problem. not too expensive
Could be a bad pump causing a low pressure problem. @ $500 to $700
You have checked your foot pedal linkages to be sure they are fully stoking the valve spool. If you are getting into float mode it sounds like they are getting the full down stroke at least.
Does your boom leak down if you leave it in the air for 30 mins? You could have a bad cylinder seal too but it would have to be really bad to not lift the front of the machine. You would likely have noticed the boom drop when the pedal is in hold (center) position
Ken

Well I bought a 3000 psi pressure gauge and hooked it up to one of the aux hydraulics. When I activated the aux you could see the hose move and then the gauge barely went up to 200 or so psi and then at 1/2 throttle it went up to 250 psi. That's it. I tried it a couple of times and made sure everything was connected properly. So, hopefully it's a pressure relief valve. Anyone have a picture of where it's at so I can make sure I am working on the right part? Thanks. Doug

 

[Tazza]

Well I bought a 3000 psi pressure gauge and hooked it up to one of the aux hydraulics. When I activated the aux you could see the hose move and then the gauge barely went up to 200 or so psi and then at 1/2 throttle it went up to 250 psi. That's it. I tried it a couple of times and made sure everything was connected properly. So, hopefully it's a pressure relief valve. Anyone have a picture of where it's at so I can make sure I am working on the right part? Thanks. Doug

It will screw into the control block housing, but not knowing exactly what control block you have, i can't tell you exactly where it is....

 

[dball]

It will screw into the control block housing, but not knowing exactly what control block you have, i can't tell you exactly where it is....

I finally got a little time to check things out a little more. It looks like the hydraulic pressure is actually ok. I guess I wasn't properly engaging the aux but when I did the pressure went up to about 2600 psi and stayed right around there when adjusting the throttle to half. The left pedal doesn't feel right to me. It seems like it's a shorter press before I hit the float detent. The bucket goes down very slow. Also, if I push with my heel to lift up it almost feels like I'm hitting a detent but jumps back into motion if I let off a little. If I push with my heel lightly then I get the arms to raise decently. I lifted the cab and followed where the pedal connects to the linkage and didn't see any obvious issues. Anyone have any ideas?

 

[AnOldFixerUpper]

I finally got a little time to check things out a little more. It looks like the hydraulic pressure is actually ok. I guess I wasn't properly engaging the aux but when I did the pressure went up to about 2600 psi and stayed right around there when adjusting the throttle to half. The left pedal doesn't feel right to me. It seems like it's a shorter press before I hit the float detent. The bucket goes down very slow. Also, if I push with my heel to lift up it almost feels like I'm hitting a detent but jumps back into motion if I let off a little. If I push with my heel lightly then I get the arms to raise decently. I lifted the cab and followed where the pedal connects to the linkage and didn't see any obvious issues. Anyone have any ideas?

I don't know the machine well, but you might want to look for obstructions around the linkages that control the associated spool valve.. when you had it in for service they may have reinstalled a line that is interfering with your control linkage.

 

[dball]

I don't know the machine well, but you might want to look for obstructions around the linkages that control the associated spool valve.. when you had it in for service they may have reinstalled a line that is interfering with your control linkage.

I've been checking things out and I'm almost certain it's something with the lift spool. I had a guy replace the seals on the lift spool a couple months ago and everything was fine a for a few weeks. I don't know if changing the hydro fluid at the bobcat dealership triggered anything or not. I got the guy that worked on it before checking it out sometime in the next couple of days. Can't wait to get it working right again!

 

[skidsteer.ca]

I've been checking things out and I'm almost certain it's something with the lift spool. I had a guy replace the seals on the lift spool a couple months ago and everything was fine a for a few weeks. I don't know if changing the hydro fluid at the bobcat dealership triggered anything or not. I got the guy that worked on it before checking it out sometime in the next couple of days. Can't wait to get it working right again!

Disconect the linkage from the spool and see if the travel of the spool is equal in each direction. Ifit is not remove the cover on the rear end of the spool to see if thebolt holding the centering spring is coming loose or perhaps the spring has broke or somehow soe other forein debris is in there.
Ken