1989 632 screaming on turning not turning well - need help.

[BoBoV8]

Salut j'ai un problème similaire, toutes les commandes hydrauliques consomment trop d'énergie du moteur et calent, direction difficult also I shared a video of the problem, probably the worn part like yours.

I had a 642 that would scream. This was my fix.
I diagnosed the pump by switching the hoses for the hydro motors at the pump. After switching hoses joy sticks operate totally opposite from normal operation so be careful to have space and be prepared to drive with different orientation. When I switched my hoses the problem went from the left hydro to the right hydro indicating that the hydro motors were good and the problem was the pump. Total cost of repair around $400.

Hi all! First thanks again, for all your info!! As explained, this is my first wheel loader / bobcat / clark. After all your infos I started to dig into this thing...
1. I found out, that the "funny noise" I heared seems to be very common and kind of "normal".
2. I wanted to be sure that there is no locked break or that the drive chains are over thightened / or even to loose. So I started to get into this old rig... what I found inside the bobcat was a dark, oily, sticky, slimy, rusty "grave", different rotten hydraulic hoses, a leaking hydraulic oil tank and the blewn tilt cylinder....
I couldn't find any kind of break ( think one of the former owners solved all possible break issues finally). ...so it became clear why there was no break pedal....
Only thing i could find was that there was the double amount of oil in the chaincase which has to be in there. > for me could be one of the reasons why this rig was so oily.
But apart from this, the heavy corossion, a blewn tilt cylinder and rotten hoses there was nothing which looked not OK, and at least the thing was running and operating. So I disassembled, the rig, cleaned it, grinded it (so far as possible) painted it, changed the tilt cylinder and replaced all rotten hoses. I installed new aftermarked fuel tanks and put a new hydraulic oil tank on. Now I just started to put all pieces together again.

What I am wondering now is, how to vent / bleed the air out of the hydraulic system?? Any Ideas? Many thanks in advance!

 

[jp8775]

I have had a 632 for 20 years. I love it. #1 it has to be full of good hydrolic oil, #2 it has to have a good hydrolic oil filter no clogged at all, #3 it needs to be run wide open. It will scream if you are not wide open. There is not that much HP there especially with a older motor. I do not know how many hours are on mine as the hour meter has never worked. I can go through the engine for just a few hundred dollers and just a new valve job will add much needed hp to the 632.

 

[BoBoV8]

I have had a 632 for 20 years. I love it. #1 it has to be full of good hydrolic oil, #2 it has to have a good hydrolic oil filter no clogged at all, #3 it needs to be run wide open. It will scream if you are not wide open. There is not that much HP there especially with a older motor. I do not know how many hours are on mine as the hour meter has never worked. I can go through the engine for just a few hundred dollers and just a new valve job will add much needed hp to the 632.

This is the first time I hear to run it wide open and that it would scream if not... I will definetly try it ....once it's completed again. But do you have any idea, how to refill the hydraulics in a way, that 1. I won't damage the pump or the drive motors because there is not enough / no oil in - or better to much air? How could I be sure that there will be everywhere (enough) oil and no air in the whole hydraulics? I had the pump and the tilt out and changed different hoses. So the thing should be pretty empty / dry. I filled a new oilfilter with oil and installed it. And I was rinsing (with a thin hose out of the oil can) directly into the - new - tank / filling hose. My idea was that this way the oil would slowly penetrate the whole system down to "the bottom" without trapping the air in it. My hope was that this way would be enough space in the hoses / pipes of system that the air would bleed out the same way as the oil rinses in.... but I am not sure that it did work. The whole system (without hydraulic tank) took less than a half gallon ...OK, maybe not all hoses / pipes have been total empty, and for sure the pipe up to the oilcooler / filter is still empty because it's higher leveled position but....? How could I be sure? And how could I get possible air out of the system - before running it (and of course during and after running it)? Any ideas? I am looking forward to all good ideas, infos and recommendations! Many thanks in advance to all! Bobo

 

[BoBoV8]

This is the first time I hear to run it wide open and that it would scream if not... I will definetly try it ....once it's completed again. But do you have any idea, how to refill the hydraulics in a way, that 1. I won't damage the pump or the drive motors because there is not enough / no oil in - or better to much air? How could I be sure that there will be everywhere (enough) oil and no air in the whole hydraulics? I had the pump and the tilt out and changed different hoses. So the thing should be pretty empty / dry. I filled a new oilfilter with oil and installed it. And I was rinsing (with a thin hose out of the oil can) directly into the - new - tank / filling hose. My idea was that this way the oil would slowly penetrate the whole system down to "the bottom" without trapping the air in it. My hope was that this way would be enough space in the hoses / pipes of system that the air would bleed out the same way as the oil rinses in.... but I am not sure that it did work. The whole system (without hydraulic tank) took less than a half gallon ...OK, maybe not all hoses / pipes have been total empty, and for sure the pipe up to the oilcooler / filter is still empty because it's higher leveled position but....? How could I be sure? And how could I get possible air out of the system - before running it (and of course during and after running it)? Any ideas? I am looking forward to all good ideas, infos and recommendations! Many thanks in advance to all! Bobo

 

[Judah]

This is the first time I hear to run it wide open and that it would scream if not... I will definetly try it ....once it's completed again. But do you have any idea, how to refill the hydraulics in a way, that 1. I won't damage the pump or the drive motors because there is not enough / no oil in - or better to much air? How could I be sure that there will be everywhere (enough) oil and no air in the whole hydraulics? I had the pump and the tilt out and changed different hoses. So the thing should be pretty empty / dry. I filled a new oilfilter with oil and installed it. And I was rinsing (with a thin hose out of the oil can) directly into the - new - tank / filling hose. My idea was that this way the oil would slowly penetrate the whole system down to "the bottom" without trapping the air in it. My hope was that this way would be enough space in the hoses / pipes of system that the air would bleed out the same way as the oil rinses in.... but I am not sure that it did work. The whole system (without hydraulic tank) took less than a half gallon ...OK, maybe not all hoses / pipes have been total empty, and for sure the pipe up to the oilcooler / filter is still empty because it's higher leveled position but....? How could I be sure? And how could I get possible air out of the system - before running it (and of course during and after running it)? Any ideas? I am looking forward to all good ideas, infos and recommendations! Many thanks in advance to all! Bobo

I have repaired the port block, leaking hoses, and drive motors on my 632. The manual states that it is a self bleeding system so I have always just filled up the reservoir and run the machine for a minute using all the hydraulic components and then checked the level and filled again as needed.

 

[Judah]

Hi all! First thanks again, for all your info!! As explained, this is my first wheel loader / bobcat / clark. After all your infos I started to dig into this thing...
1. I found out, that the "funny noise" I heared seems to be very common and kind of "normal".
2. I wanted to be sure that there is no locked break or that the drive chains are over thightened / or even to loose. So I started to get into this old rig... what I found inside the bobcat was a dark, oily, sticky, slimy, rusty "grave", different rotten hydraulic hoses, a leaking hydraulic oil tank and the blewn tilt cylinder....
I couldn't find any kind of break ( think one of the former owners solved all possible break issues finally). ...so it became clear why there was no break pedal....
Only thing i could find was that there was the double amount of oil in the chaincase which has to be in there. > for me could be one of the reasons why this rig was so oily.
But apart from this, the heavy corossion, a blewn tilt cylinder and rotten hoses there was nothing which looked not OK, and at least the thing was running and operating. So I disassembled, the rig, cleaned it, grinded it (so far as possible) painted it, changed the tilt cylinder and replaced all rotten hoses. I installed new aftermarked fuel tanks and put a new hydraulic oil tank on. Now I just started to put all pieces together again.

What I am wondering now is, how to vent / bleed the air out of the hydraulic system?? Any Ideas? Many thanks in advance!

If your chain case was super overfull I wonder if you will need to rebuild one or both drive motors? I would keep and eye on the oil level in there after you get the machine up and running again.

 

[BoBoV8]

If your chain case was super overfull I wonder if you will need to rebuild one or both drive motors? I would keep and eye on the oil level in there after you get the machine up and running again.

Thank you so much! I fear you could be right. I couldn't start till now, because all these little bits and pieces which "want" to be repaired or improved before putting it all together again... but what I can already say is, that the pump is leaking somewhere at the front end, and only by the pressure of the oil in the reservoir. And under the loader is a large oil puddle again, too. I just noticed it when I was in the shop early this morning, when I pepared my truck for work. I didn't have had the time to take a closer look, but it was enough to make me sad....
Is this a common thing, that these pumps are leaking "somewhere" on the downside of the pump. Could this be fixed without pulling the whole pump again. Has anybody any experiences?

 

[Judah]

Thank you so much! I fear you could be right. I couldn't start till now, because all these little bits and pieces which "want" to be repaired or improved before putting it all together again... but what I can already say is, that the pump is leaking somewhere at the front end, and only by the pressure of the oil in the reservoir. And under the loader is a large oil puddle again, too. I just noticed it when I was in the shop early this morning, when I pepared my truck for work. I didn't have had the time to take a closer look, but it was enough to make me sad....
Is this a common thing, that these pumps are leaking "somewhere" on the downside of the pump. Could this be fixed without pulling the whole pump again. Has anybody any experiences?

Well… I had a similar sounding leak and ending up replacing the seal on the pump shaft. It was easier to pull the engine than the pump, especially since I already had most of the engine components taken apart for repair. There is a very good YouTube video by a guy who did the same repair. I'll see if I can find it and share the link.

 

[Judah]

Thank you so much! I fear you could be right. I couldn't start till now, because all these little bits and pieces which "want" to be repaired or improved before putting it all together again... but what I can already say is, that the pump is leaking somewhere at the front end, and only by the pressure of the oil in the reservoir. And under the loader is a large oil puddle again, too. I just noticed it when I was in the shop early this morning, when I pepared my truck for work. I didn't have had the time to take a closer look, but it was enough to make me sad....
Is this a common thing, that these pumps are leaking "somewhere" on the downside of the pump. Could this be fixed without pulling the whole pump again. Has anybody any experiences?

Check out Savvy Sprocket on YouTube he goes through the whole pump shaft seal replacement. Also a good idea to take apart your port block to clean out the filters and change the orings.

 

[BoBoV8]

Check out Savvy Sprocket on YouTube he goes through the whole pump shaft seal replacement. Also a good idea to take apart your port block to clean out the filters and change the orings.

Thanks, the "Savvy Sprocket" story I know. I pulled engine and pump. The pump shaft seal seemed to be fine. The whole area (backside of the pump, engine flywheel) has been dry and (in competition to the rest) clean. Now, so far I could see this morning, I have a puddle on top of the chaincase below the port bolck and (I think it's called?) the vene pump. But I will have a closer look by tomorrow. My big hope is that I can fix it, without pulling all completely out again... I am totally allone and haven't got the right space and equipment/tools to do this stuff. I pulled the engine and put it back in again allone with my bare hands and a car jack - and I am happy that it worked and that I did not break me any bones or my back.... I willingly would avoid to do it again... especially if I worst case would have to take out and to seal the drivemotors, too. I bought this bloody rig to build a driveway.... since I bought it I am working on it and the building permit is running out soon.... it's a mess...