1994 763 hydro problem

[jsjmall4]

Need help! I have 763 bobcat that is on loan from a friend. Because of this I do not Know alot of the ins and outs of this machine. the problem I am having is the hydro warning light stays on for a long time when you start the engine. When the light is on the hydraulics do not work. After the light goes out it works fine. I am thinking that the filter probably needs replacing. Just needed a second opp. before Iwent to the parts store.

 

[thetool]

If it worked with the light on, I would say yeah-get a filter.
There are three things that give you a light. Temperature, charge pressure and filter by-pass. It is common in cold weather to get a light from filter by-pass, but that won't keep it from running, and it tends to go away after warm-up.
The only thing that keeps it from working AND gives you a light is low charge pressure, which is potentially damaging to the machine, even just setting there idling.
It's odd to me because things that cause low charge pressure don't go away after warm-up.
If it was me, I wouldn't even start the machine, but would be giving the owner a heads-up.

 

[jsjmall4]

If it worked with the light on, I would say yeah-get a filter.
There are three things that give you a light. Temperature, charge pressure and filter by-pass. It is common in cold weather to get a light from filter by-pass, but that won't keep it from running, and it tends to go away after warm-up.
The only thing that keeps it from working AND gives you a light is low charge pressure, which is potentially damaging to the machine, even just setting there idling.
It's odd to me because things that cause low charge pressure don't go away after warm-up.
If it was me, I wouldn't even start the machine, but would be giving the owner a heads-up.

I did speak to the owner, he said it had not done that in the past . He said it has not been used in about 2 months. What causes low chargw pressure. Ihave checked the hydro oil and it has always been at the correct level and looks good.

 

[jsjmall4]

I did speak to the owner, he said it had not done that in the past . He said it has not been used in about 2 months. What causes low chargw pressure. Ihave checked the hydro oil and it has always been at the correct level and looks good.

I need to ad one thing to my original post for you to consider. When the light is on the hydraulic pump fan and pump are not working.

 

[thetool]

I need to ad one thing to my original post for you to consider. When the light is on the hydraulic pump fan and pump are not working.

A 1994 763 does not have a hydraulic pump fan.......but that gives another clue.....=).
Okay-I think you need to check your main drive belt tension, and your fan frive belt attached to the pump pulley-and also check for ice in and around the fan.
That could cause this problem, and your pump is spinning up after it warms up-I'm guessing here.

 

[jsjmall4]

A 1994 763 does not have a hydraulic pump fan.......but that gives another clue.....=).
Okay-I think you need to check your main drive belt tension, and your fan frive belt attached to the pump pulley-and also check for ice in and around the fan.
That could cause this problem, and your pump is spinning up after it warms up-I'm guessing here.

Thanks (thetool) . The year i was going by is what the owner told me sorry for that. I live in alabama so the ice is not an issue. When the light comes on it will shut down the hydraulics but the engine runs fine. When the hydro stops the fan also shuts off. When the hydrailics are working they have a good bit of whine but not to bad in my oppion. The problem was just on start up until today after about 5 hours of use the light came on and will not go off now and hdyro want work. What will cause low charge pressure.

 

[mllud]

Thanks (thetool) . The year i was going by is what the owner told me sorry for that. I live in alabama so the ice is not an issue. When the light comes on it will shut down the hydraulics but the engine runs fine. When the hydro stops the fan also shuts off. When the hydrailics are working they have a good bit of whine but not to bad in my oppion. The problem was just on start up until today after about 5 hours of use the light came on and will not go off now and hdyro want work. What will cause low charge pressure.

The Tool has a good suggestion in his last post. Forget about the ice build up. The belt could be loose. Most likely.
Okay-I think you need to check your main drive belt tension, and your fan frive belt attached to the pump pulley-and also check for ice in and around the fan. Mike

 

[Tazza]

The Tool has a good suggestion in his last post. Forget about the ice build up. The belt could be loose. Most likely.
Okay-I think you need to check your main drive belt tension, and your fan frive belt attached to the pump pulley-and also check for ice in and around the fan. Mike

Agreed, i was reading and though hello! drive belt.
The main drive belt runs the hydro pumps, the main cooling fan runs off the pulley on the pump, so if the pully isn't turning the fan won't either, i'd put money on the drive belt!

 

[jsjmall4]

Agreed, i was reading and though hello! drive belt.
The main drive belt runs the hydro pumps, the main cooling fan runs off the pulley on the pump, so if the pully isn't turning the fan won't either, i'd put money on the drive belt!

Thanks for the info. Can you get to it from the rear or will I need to raise the cab. What should I be looking for as far as tension or replacing the belt. If I need to replace it, is this easily done. If it is not the belt is there a clutch that activates the belt that may not be working. Again thanks for the info it is very helpful

 

[skidsteer.ca]

Thanks for the info. Can you get to it from the rear or will I need to raise the cab. What should I be looking for as far as tension or replacing the belt. If I need to replace it, is this easily done. If it is not the belt is there a clutch that activates the belt that may not be working. Again thanks for the info it is very helpful

Pretty straight forward, from the rear on the left side. you may need a new belt but a good chance its loose too. There is no clutch on the 763.
Remove the sping clips and remove the black plastic cover from the bell housing. inspect the belt for tension and damage. You need a 9/16” wrench to loosen the tensioner and a prybar to hold it down while you retighten the bolt to lock it.
Some of the early belt drive loaders had fixed tensioners while the later ones are spring loaded to automatically take up some belt slack. If its spring loaded the pointer by the idler pulley will point to 1 oclock if the spring is completely un wound. You pry the tensioner down so the point is @ 3 oclock or a little less.
If its the early tensioner just use common sense and snug the belt up. it does not have to be crazy tight. Which wouldbe hard on the bearings.
Ken

 

[jsjmall4]

Pretty straight forward, from the rear on the left side. you may need a new belt but a good chance its loose too. There is no clutch on the 763.
Remove the sping clips and remove the black plastic cover from the bell housing. inspect the belt for tension and damage. You need a 9/16” wrench to loosen the tensioner and a prybar to hold it down while you retighten the bolt to lock it.
Some of the early belt drive loaders had fixed tensioners while the later ones are spring loaded to automatically take up some belt slack. If its spring loaded the pointer by the idler pulley will point to 1 oclock if the spring is completely un wound. You pry the tensioner down so the point is @ 3 oclock or a little less.
If its the early tensioner just use common sense and snug the belt up. it does not have to be crazy tight. Which wouldbe hard on the bearings.
Ken

Thanks for all the help. I will try this in the morning and update the forum. Thanks again

 

[jsjmall4]

Thanks for all the help. I will try this in the morning and update the forum. Thanks again

Update. It was a broken pump drive belt. The model i have has the spring loaded tensioner. I am guessing that all I have to do is get a belt and pry up on the pulley to install it, is this correct.If not can someone explain what the process would be. Also does any one know of a site that has part number lookup. The place that carries bobcat equipment here is closed until monday. I was hoping I couyld cross reference the number for another belt.

 

[Fishfiles]

Update. It was a broken pump drive belt. The model i have has the spring loaded tensioner. I am guessing that all I have to do is get a belt and pry up on the pulley to install it, is this correct.If not can someone explain what the process would be. Also does any one know of a site that has part number lookup. The place that carries bobcat equipment here is closed until monday. I was hoping I couyld cross reference the number for another belt.

You need to check the idler bearing before replacing the belt , I got a feeling yours may be bad from the way you discribed it acted --------

 

[skidsteer.ca]

You need to check the idler bearing before replacing the belt , I got a feeling yours may be bad from the way you discribed it acted --------

I doubt you will get the new belt on without backing off the tensioner by loosening the 3/8” bolt 9/19” wrench and letting the idler slide upwards. New belts often stretch some during the first 25 to 50 hours .
If you manage to cross the belt let us know the #
Ken

 

[jsjmall4]

I doubt you will get the new belt on without backing off the tensioner by loosening the 3/8” bolt 9/19” wrench and letting the idler slide upwards. New belts often stretch some during the first 25 to 50 hours .
If you manage to cross the belt let us know the #
Ken

Sorry I didn't update before now. Everything you guys told me was 100% correct. I replaced the belt and finished the work. My friend sold that machine just after that and i have been looking for one for my self since. I finally found one that I think is a good price and in good shape. I am sure that I will be back for advice again. Thank you for all the help. Sites like this have saved me thousands of dollars. I have found that if you are willing to try to fix it and have the ability , the advice you get can take you the rest of the way.