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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
- Thread starter NORTHCOASTLLC
- Start date
uffex
Senior Member
Good day
Sounds like low servo pressure, if you have a hydraulic schematic may be able to help some.
Kind regards
Uffex
Sounds like low servo pressure, if you have a hydraulic schematic may be able to help some.
Kind regards
Uffex
skyking1
Senior Member
NORTHCOASTLLC
Member
Update
Received my new hydro pressure gauges today. My basic plan at this point is to test the pressure from the pump at low rpm and then at high rpm. Hopefully see some proof of whats not doing what it is supposed to do.
Received my new hydro pressure gauges today. My basic plan at this point is to test the pressure from the pump at low rpm and then at high rpm. Hopefully see some proof of whats not doing what it is supposed to do.
NORTHCOASTLLC
Member
Anyone have advise for us when hooking up the pressure testing gauges? Here is a photo of what I'm looking to tap into. Does anyone see a pressure relief valve in this photo? It would be great to test specific functions and pressures without having to drain the reservoir tank in order to remove the pump for visual inspection of the internals.
Last edited:
aongheas.macask
Well-Known Member
NORTHCOASTLLC
Member
Please tell us where or what the spool block is. We don't have a lot of experience with this.
aongheas.macask
Well-Known Member
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 are looking at will be pointless in my opinion
NORTHCOASTLLC
Member
What I meant was I haven't had much experience working on this excavator. The knowledge base in my shop covers everything from race cars to heavy ag equipment. This Leiberr is an old girl and I can't find a service manual anywhere. Can we confirm that what we are looking for is not in this photo?
NORTHCOASTLLC
Member
NORTHCOASTLLC
Member
aongheas.macask
Well-Known Member
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
NORTHCOASTLLC
Member
This looks to me like a pressure testing manifold. Am I right?
NORTHCOASTLLC
Member
aongheas.macask
Well-Known Member
correct
NORTHCOASTLLC
Member
Progress. I got my new pressure gauges attached to the testing manifold. At wot the gauges show ample pressure. Everything operates.... a little jerky but not bad. When I back off the throttle 20% the gauges show nothing, everything stops working. After researching the Linde AG main hydraulic pump B2PV105 it looks like a rebuild kit is available for about $1,500 usd from China. Has anyone on this forum ever rebuilt this type of pump? I have searched everywhere for manuals but can't find anything. If we have to pull the entire unit from the excavator we have the machinery to do it. However, it would be amazing to find out if the unit can be rebuilt / repaired by opening up the case when it's still in the excavator. I realize this might be a long shot but worth looking into. I will attach a few photos with some red labeling. Not fishing for free spoon-fed advise. We are happy to pay for direction with this situation. It would be frustrating to pull the entire pump and find out the repairs could have been made while it was still in the excavator. I am currently rigging up a larger pressure test system that will be right at the pump pressure outlet. Probably worth the effort to make sure the main pump internals are the problem.
Attachments
aongheas.macask
Well-Known Member
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. A good hydraulic shop should be able to overhaul this pump but I would be very wary of using Chinese components from a quality standpoint.
NORTHCOASTLLC
Member
Thank you for your advice. I appreciate it. JH
NORTHCOASTLLC
Member
Update
Local Hydraulics tech had the following input. If the pressures meet specs at full throttle there probably isn't anything wrong with the pump(s). He explained how there was a hydraulic system on top of a hydraulic system in this Lieberr. He explained in more detail. We are trying to find the valve, or vane that adjusts pressure depending on throttle position. Does this sound familiar to anyone?
Local Hydraulics tech had the following input. If the pressures meet specs at full throttle there probably isn't anything wrong with the pump(s). He explained how there was a hydraulic system on top of a hydraulic system in this Lieberr. He explained in more detail. We are trying to find the valve, or vane that adjusts pressure depending on throttle position. Does this sound familiar to anyone?
