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    Cab Hydro Controls only work when engine is full throttle. Any less RPM=Nothing will operate / No track movement or bucket movement

    I think the air valves are for swing and travel brakes
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    Cab Hydro Controls only work when engine is full throttle. Any less RPM=Nothing will operate / No track movement or bucket movement

    Sorry I don't know about that but best of luck anyway, keep us posted after you rebuild the pump.
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    Cab Hydro Controls only work when engine is full throttle. Any less RPM=Nothing will operate / No track movement or bucket movement

    On the bottom of the piston barrels there should be a brass running surface, ensure there are no scores on them as this runs against the swash plate and any marks or scores will cause a drop in pressure
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    Cab Hydro Controls only work when engine is full throttle. Any less RPM=Nothing will operate / No track movement or bucket movement

    The pistons look to be scored,, maybe it's just the photograph,what are the barrels like inside,can you see or feel any scores of marks?
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    Cab Hydro Controls only work when engine is full throttle. Any less RPM=Nothing will operate / No track movement or bucket movement

    How are you measuring pressure, you need to end stop a cylinder and hold it end stopped to see what pressure the main relief valve opens at, as you slowly reduce the engine revs the pressure should be pretty constant ,if the pressure drops at the same time as the revs this is usually an...
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    Cab Hydro Controls only work when engine is full throttle. Any less RPM=Nothing will operate / No track movement or bucket movement

    The hyd pressure is set by the main relief valves not by engine speed, the hydraulic pump output flow will reduce as revs drops but if the pump is good pressure should be maintained until near stalling point. A worn pump will usually not maintain pressure as the rpm drops
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    Genuine VS Chinese parts

    Don't do it, 250 dollars/euros with shipping included sounds ridiculous unless the parts are made of chocolate or wood. Just my opinion.
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    Return filter blocked???

    Perhaps you could tell us what machine your are having trouble with.
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    Cab Hydro Controls only work when engine is full throttle. Any less RPM=Nothing will operate / No track movement or bucket movement

    The kit in your photograph is only the main barrel and pistons, this is not a rebuild kit,,you will require two of these,plus servo shafts,bearings,seals etc. The pump will need to be removed for overhaul/rebuild. Linde made good pumps and I suggest you contact them or one of their distributors...
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    Return filter blocked???

    Don't know what machine this is but if return filter is blocked it will normally go into bypass, in itself this would not cause slow hydraulics unless as Coaldust suggests your hyd pump has destroyed itself , finding steel and brass in the filter would be a good indication, good luck
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    Cab Hydro Controls only work when engine is full throttle. Any less RPM=Nothing will operate / No track movement or bucket movement

    correct
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    Liebherr 731C blade won’t work

    Sorry, I'm not sure as it's a long time since I worked on these machines.
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    Liebherr 731C blade won’t work

    Check your servo cut out switch on safety lever
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    Cab Hydro Controls only work when engine is full throttle. Any less RPM=Nothing will operate / No track movement or bucket movement

    Yes, the second photo 135426 shows the spook blocks, Main relief valve is on the right of the four spoolcaps, hex locknut with Allen head adjuster in centre
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    Cab Hydro Controls only work when engine is full throttle. Any less RPM=Nothing will operate / No track movement or bucket movement

    Follow the hoses from the hyd cylinders, they go to the spoolblocks. Perhaps you should employ an experienced mechanic before messing about with high pressure hydraulics. I understand you have no experience but if you have zero knowledge then hooking up pressure gauges without knowing what you...
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    Cab Hydro Controls only work when engine is full throttle. Any less RPM=Nothing will operate / No track movement or bucket movement

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    Hydraulic in diesel tank

    They were Bosch
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    Hydraulic in diesel tank

    I seen this before on a Liebherr excavator where a combined fuel and hydraulic tank had a crack in the weld which seperated the two tanks and allowed the hyd oil into the fuel, this caused the injectors to gum up and produce lots of smoke, the owner changed injectors twice before calling field...
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    Liebherr 731C won't move - diagnosing or loading it on a trailer while dead

    Not easy but doable, you need to tilt the cab for access, Remove bolts on front of cab at steps on either side ,there is a hydraulic handpump on left hand side to jack up the cab
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    Liebherr 731C won't move - diagnosing or loading it on a trailer while dead

    1' the other dipstick is for the splitter box ( two drive pumps and one pump for blade).,Remove plate on top of tank and fill with oil thru the filter.. 2' You need to remove both drive motors from final drives to tow machine. 3' they are separate systems. Drive system is closed loop and blade...
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