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Help !! Case 1550 No hydraulics power.

S

Sureshot

New Member
Joined
Oct 4, 2019
Messages
4
Location
Corinth
okay. So. I am new to this form. Or any form. Please don’t give me to hard of a time on my post.

I own a case 1550. Dozer it is hydrostatic driven. With three pumps. One pump for the left side drive. One pump for the right side. Drive and one pump for. Equipment control like. Blade. So I was pushing. A tree down and. Like a switch I lost all power. To blade and and both left and right side. Drive. The drive motors won’t move forward or reverse. And the blade has no function as well. It didn’t act as it was getting weak. Or. Felt like it was losing. Power. It. Just stopped all suddenly. Just like a light switch. So I killed the machine thinking the worst. And after a a few days. Went by I went out and fired it back up again. I was like okay. It’s fine. It’s all working again. I have full power. And I mean full power. In the. drive motors and in the blade controls. Then. Again just like you turned off a switch in about 2 mins or less I lost. Everything again. I lost all blade function and. Drive. Motors. Stopped all suddenly again.

I don’t see any major leaks. Or any major fluid loss. I don’t. hear any grinding or smell any thing burning. It seams as normal. .

I am lost with the issue of this dozer. So I waited for about three or four more days. Went out and hooked up all the gauges and. Had all. Proper. Pressure. I had 2500 plus psi on the blade control. And the drive motors where at specs of the book. I can’t remember the exact pressure but it was within the limits of the standard. For this dozer. For about two mins or. Less then I lose all pressure to both drive motors and blade control. All suddenly. It’s not a gradual. Loss. It is just like you turned off light switch. So. Please. If anyone has some insight on what is going wrong. With my dozer.
Please. Respond and let me know.

BbThanks shane.
 
F

fastline

Senior Member
Joined
Aug 8, 2011
Messages
1,106
Location
OK
Do you have a hydro schematic? I don't know the machine but possible that your pumps are variable displacement in which the controls will activate pilots to the servo controls in the pumps. Full pressure would be max stroke, and no pressure would be zero stroke, or zero volume. Can you confirm how the pumps operate? Just off the cuff, it sounds like either an electrical issue or, if not electrically actuated, a pilot pump circuit that is common to all pumps could at fault. A pilot pump typically would be a gear pump in which the pump is chew itself up or it is not getting oil due to an intake issue.
 
Dave Neubert

Dave Neubert

Senior Member
Joined
Jul 18, 2018
Messages
1,660
Location
Monroe NC
Does your hyd. tank have a suction screen ob maybe a rag in the tank for everything to stop at once sounds like a supply problem
 
S

Sureshot

New Member
Joined
Oct 4, 2019
Messages
4
Location
Corinth
Well I thought that at first. But. It really couldn’t. Be supply problem, because the drive motors Pumps. Have there own supply tank, separate from the equipment supply tank. So it is very unlikely that two totally separate tanks got clogged. At the same time. Causing failure.
 
K

kith

Well-Known Member
Joined
Oct 5, 2009
Messages
96
Location
iowa
Have you checked the oil in the pump drive? The pump drive is the only thing all three pumps have in common. You could pull the equipment pump off then run the machine until you lose drive pressure. My quess is the pump drive for the equipment pump won't be turning.
 
alrman

alrman

Senior Member
Joined
Jun 20, 2009
Messages
3,308
Location
QLD Australia
Occupation
Diesel Fitter;Small Business Owner;Cleaner
Welcome on your first post @Sureshot

Also take a look in the bellhousing, there is a plug at the bottom.
See if there is debris from a broken drive/flex plate or bolts etc.
That would stop all three pumps from turning, but can't explain the 2 min run time.
 
S

Sureshot

New Member
Joined
Oct 4, 2019
Messages
4
Location
Corinth
kith said:
Have you checked the oil in the pump drive? The pump drive is the only thing all three pumps have in common. You could pull the equipment pump off then run the machine until you lose drive pressure. My quess is the pump drive for the equipment pump won't be turning.
Click to expand...

So I checked the drive housing (Transmission) fluid it all looked good the only odd thing is it looked as it was overfilled. So I drained it. And put appropriate amount of fluid level. Back in drive housing (Transmission.) So then I started wondering if there is any way fluid could by pass over from the pump into the. drive housing (transmission). As if there is a seal that could be bad.?

I called an older gentleman about my dozer he said there is like hard rubber bushing or plate. that is mounted like between the flywheel and pump gears. That is possibly bad. And I have pressure build. Up in the housing causing, this some what rubber bushing to stall out. Or not work as it’s post work. Sounds crazy. He says the reason why it will run like it has nothing wrong or any problems for a min or two is because. I have a slow leak of pressure on the systems And when I crank it and run it the pressure starts to build up. Causing this rubber bushing or rubber plate to not work appropriately. Who knows.

I will see about pulling off the equipment pump and checking it that way. It. Is definitely blowing my mind.

My other question is there any way that. The two different supply tanks. Ever cross and it could be pulling from. One stopped stainer or filter. Or sucking air. ? To cause. All the. Three pumps to stop working all sudden. I have looked in my service Manual and I can’t see anywhere. They cross. But didn’t know if I am over looking something where it could be. Possible? Or even if that Could ever even be the issue. Other than the drive housing.(Transmission).
 
K

kith

Well-Known Member
Joined
Oct 5, 2009
Messages
96
Location
iowa
The only thing they have in common is the drive. If the drive housing is filling up you have a seal leaking from one of the three pumps.
 
F

fastline

Senior Member
Joined
Aug 8, 2011
Messages
1,106
Location
OK
Apparently I didn't have a good enough idea to get a hydro schematic. I guess pulling pumps and guessing is easier. A flex coupler will not work one day, then not the next. You need to consider the best advice I can give, which is GET A SCHEMATIC. Only then can you understand the plumbing and what is going on.
 
K

kith

Well-Known Member
Joined
Oct 5, 2009
Messages
96
Location
iowa
Sureshot said:
okay. So. I am new to this form. Or any form. Please don’t give me to hard of a time on my post.

I own a case 1550. Dozer it is hydrostatic driven. With three pumps. One pump for the left side drive. One pump for the right side. Drive and one pump for. Equipment control like. Blade. So I was pushing. A tree down and. Like a switch I lost all power. To blade and and both left and right side. Drive. The drive motors won’t move forward or reverse. And the blade has no function as well. It didn’t act as it was getting weak. Or. Felt like it was losing. Power. It. Just stopped all suddenly. Just like a light switch. So I killed the machine thinking the worst. And after a a few days. Went by I went out and fired it back up again. I was like okay. It’s fine. It’s all working again. I have full power. And I mean full power. In the. drive motors and in the blade controls. Then. Again just like you turned off a switch in about 2 mins or less I lost. Everything again. I lost all blade function and. Drive. Motors. Stopped all suddenly again.

I don’t see any major leaks. Or any major fluid loss. I don’t. hear any grinding or smell any thing burning. It seams as normal. .

I am lost with the issue of this dozer. So I waited for about three or four more days. Went out and hooked up all the gauges and. Had all. Proper. Pressure. I had 2500 plus psi on the blade control. And the drive motors where at specs of the book. I can’t remember the exact pressure but it was within the limits of the standard. For this dozer. For about two mins or. Less then I lose all pressure to both drive motors and blade control. All suddenly. It’s not a gradual. Loss. It is just like you turned off light switch. So. Please. If anyone has some insight on what is going wrong. With my dozer.
Please. Respond and let me know.

BbThanks shane.
Click to expand...
Have you figured it out?
 
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