bobcat 843

[bobkat843]

Hi every one what a great site if you own any kind of cont equipment . I own a old bobcat 843 perkins Eng . The machine was one of the most dirtiest thing I've every worked on . man the dirt get caked in there if not pressure washed every now and then. the bc is clean new filters new glow plugs runs really good . The bad is left side drive is weak and loud .Took the hydro motor out to see if i can find something wrong but every thing seamed fine no metal shavings every plastic disc looked good any idea what mite be causing this issue . anyone have access to downloadable manual for this machine would be a great help to. Thanks

 

[Tazza]

Its possible the pump is worn causing the noise and power loss. If the pump is worn, you need to send it away to be done. They don't have replaceable wear plates, the section the rotating groups run on need to be ground and hardened to remove any scoring.

 

[cnord]

Check the bushings on the drive motor where the shaft comes out, that can cause some problems, also with this kind of drive motor the gerotor(gear area) with in the motor can get worn down, as they wear they can cause less pressure. And like Tazza said, if its not your drive motor, then it would be your drive pump. To check, switch your drive motors, put the bad one on the different side. If the problem moves with the motor, then its a bad motor, if the problem stays on the bad side, look at getting your drive pump rebuilt. Check with www.loaderpartssource.com, we should be able to get you either one, pump or motor at a good price.

 

[bobkat843]

Check the bushings on the drive motor where the shaft comes out, that can cause some problems, also with this kind of drive motor the gerotor(gear area) with in the motor can get worn down, as they wear they can cause less pressure. And like Tazza said, if its not your drive motor, then it would be your drive pump. To check, switch your drive motors, put the bad one on the different side. If the problem moves with the motor, then its a bad motor, if the problem stays on the bad side, look at getting your drive pump rebuilt. Check with www.loaderpartssource.com, we should be able to get you either one, pump or motor at a good price.

Thank you both for the response . I did end up taking it to bc dealer . he said drive motor are common problem with wear and tear . and talked me in to trying new seals and parts and give it a try .If that does not do the trick he can get me a dr motor for 500$ he also said the drive pump rarely go . That does not seam possible with anything that has seals and gaskets and what not in it plus 25 year old machine with 5000 hr but he"s the expert i hope i let you now the outcome hope fully soon Thanks again

 

[cnord]

Thank you both for the response . I did end up taking it to bc dealer . he said drive motor are common problem with wear and tear . and talked me in to trying new seals and parts and give it a try .If that does not do the trick he can get me a dr motor for 500$ he also said the drive pump rarely go . That does not seam possible with anything that has seals and gaskets and what not in it plus 25 year old machine with 5000 hr but he"s the expert i hope i let you now the outcome hope fully soon Thanks again

While they are a very good and popular drive pump and are a little better than other designs, any time you have two pieces of metal rubbing against each other you will have wear. And if you say they have 5000 hours on both halves, I would say that they are probably not in the best shape. And if they are decent now, they may not be in the short future.

 

[bobkat843]

While they are a very good and popular drive pump and are a little better than other designs, any time you have two pieces of metal rubbing against each other you will have wear. And if you say they have 5000 hours on both halves, I would say that they are probably not in the best shape. And if they are decent now, they may not be in the short future.

That's true, but if the hydro pump is starting to cause problems wouldn't both left and right side be noisy?

 

[Tazza]

That's true, but if the hydro pump is starting to cause problems wouldn't both left and right side be noisy?

No, there are two pumps, one for the left, one for the right. They are mounted into the same unit though.

 

[bobkat843]

No, there are two pumps, one for the left, one for the right. They are mounted into the same unit though.

Thanks Tazza

 

[bobkat843]

Thanks Tazza

would a control valve thats has a few leaks cause noise and friction on a bobcat 843. i removed the control box and took it to be fixed with the left gear motor to bc Thanks

 

[Tazza]

would a control valve thats has a few leaks cause noise and friction on a bobcat 843. i removed the control box and took it to be fixed with the left gear motor to bc Thanks

Its possible that a little air is getting in through the leaking seals, but i would doubt it's the cause of the noise.

 

[cnord]

would a control valve thats has a few leaks cause noise and friction on a bobcat 843. i removed the control box and took it to be fixed with the left gear motor to bc Thanks

I'm pretty sure you would need to be sucking a lot of air for that to be possible, Usually when a control valve leaks, you have problems with your tilt and lift, and not with your drive.

 

[bobkat843]

I'm pretty sure you would need to be sucking a lot of air for that to be possible, Usually when a control valve leaks, you have problems with your tilt and lift, and not with your drive.

Thanks for the education guys. hopefully soon i"ll have and answer

 

[TROLLcarver42]

been looking too. Found this site http://www.kp44.org/ftp/Perkins_4-154_Shop_Manual.pdf which applies to the _4-154/200 series which have a serial number greater than 13,000. I have a series below 13,000 manual does not apply completely and unfortunately it is where I need the most priming the engine. Serial number is outside the engine compartment attached to the left boom support just above the where the engine door opens. Brian