Hi, I have an old 1.6 tonne Schaeff HR12.
When I push both drive motor pedals or pull both levers the same distance, one track drives faster than the other. This makes it nearly impossible to drive using my feet, which I would like to do for some reason :)
Also driving backwards is sometimes impossible, one track just does not drive and the other one drives at full speed, whilst driving forwards works fine. Sometimes pushing the pedal through the floor (almost) gives some more speed.
Its always the same pedal/track. Since I have old tracks and non-functional track tensioners, the tracks really dont like driving in circles and keep skipping over the sprocket.
I need suggestions how I would go about debugging the issue to find out whether my drive engines are diying or is it just the pedal valves. I have no experience in debugging machines and I often tend to jump to the wrong conclusions, so I need you to hold my hand and tell me what to check :D
I have other weird non-critical "unexpected behaviours" (i wouldnt call them issues, because they do not hinder my productivity.. much) in hydraulic systems on my excavator aswell, but this issue is the only critical one. In case the other issues might be indicative, heres a list:
* When rotating the cab and I dont use any other hydraulic systems (like move the bucket), the rotation switches off. It comes on in the same second I move some other piston even a little.
* I can rotate the cab manually by just pushing it tens of degrees, even when the machine is working at full revs. When the mini ex is sloping to one side and I crab an extra large bucketful of material, the cab tends to want to rotate downhill - I have to apply pressure on the joystick to counter it. When moving with a large load, the rotation bearings make a weird noise, even when lubed up 5 minutes ago.
* If the revs are too low, I cannot move the arm, or rotate the cab or move the bucket. I can drive and operate the dozer blade just fine.
* Expandable tracks do not work, I can hear the revs going down when I switch to "expand tracks" mode and operate the dozer blade lever. Nothing happens, no expansion, not even a millimeter. No other hoses move when I operate the lever, so it should be going to the expansion cylinder.
* When I first start the mini ex, the pressure in the hydraulic cylinders is so weak, that if I lift the arm, it will sag down immediately. After working for a few hours and even idling at 20-30% revs, the arm will stay in the air without dropping a millimeter forever. I have encountered this on every other machine, but the starting-up weakness is the biggest I've seen. Is this normal? Can I speed it up?
Its impossible to change buckets when the machine is cold, other than that its not that big of a deal.
* When moving forwards, there is not enough power to rotate the cab or move the arm. However when rotating the cab, it is possible to move the arm and bucket, but they are very weak in that situation.
The system is not losing hydraulic oil, atleast I haven't seen big puddles of anything when the mini ex is parked in one spot for a long while.
When I push both drive motor pedals or pull both levers the same distance, one track drives faster than the other. This makes it nearly impossible to drive using my feet, which I would like to do for some reason :)
Also driving backwards is sometimes impossible, one track just does not drive and the other one drives at full speed, whilst driving forwards works fine. Sometimes pushing the pedal through the floor (almost) gives some more speed.
Its always the same pedal/track. Since I have old tracks and non-functional track tensioners, the tracks really dont like driving in circles and keep skipping over the sprocket.
I need suggestions how I would go about debugging the issue to find out whether my drive engines are diying or is it just the pedal valves. I have no experience in debugging machines and I often tend to jump to the wrong conclusions, so I need you to hold my hand and tell me what to check :D
I have other weird non-critical "unexpected behaviours" (i wouldnt call them issues, because they do not hinder my productivity.. much) in hydraulic systems on my excavator aswell, but this issue is the only critical one. In case the other issues might be indicative, heres a list:
* When rotating the cab and I dont use any other hydraulic systems (like move the bucket), the rotation switches off. It comes on in the same second I move some other piston even a little.
* I can rotate the cab manually by just pushing it tens of degrees, even when the machine is working at full revs. When the mini ex is sloping to one side and I crab an extra large bucketful of material, the cab tends to want to rotate downhill - I have to apply pressure on the joystick to counter it. When moving with a large load, the rotation bearings make a weird noise, even when lubed up 5 minutes ago.
* If the revs are too low, I cannot move the arm, or rotate the cab or move the bucket. I can drive and operate the dozer blade just fine.
* Expandable tracks do not work, I can hear the revs going down when I switch to "expand tracks" mode and operate the dozer blade lever. Nothing happens, no expansion, not even a millimeter. No other hoses move when I operate the lever, so it should be going to the expansion cylinder.
* When I first start the mini ex, the pressure in the hydraulic cylinders is so weak, that if I lift the arm, it will sag down immediately. After working for a few hours and even idling at 20-30% revs, the arm will stay in the air without dropping a millimeter forever. I have encountered this on every other machine, but the starting-up weakness is the biggest I've seen. Is this normal? Can I speed it up?
Its impossible to change buckets when the machine is cold, other than that its not that big of a deal.
* When moving forwards, there is not enough power to rotate the cab or move the arm. However when rotating the cab, it is possible to move the arm and bucket, but they are very weak in that situation.
The system is not losing hydraulic oil, atleast I haven't seen big puddles of anything when the mini ex is parked in one spot for a long while.