What to do when the hydraulic pump starts to leak?
In the world of construction machinery, a hydraulic system failure is a serious problem that can paralyze the operation of the entire excavator. One such situation was the repair of the A11V130 pump from the Caterpillar M315 machine, which came to our workshop due to oil leaks.
What did the diagnostics, disassembly, and reassembly of the pump look like? We invite you to read and watch the video!
Diagnosis: leaks and time for inspection
The pump came to us with clear signs of wear – visible leaks suggested worn seals or deeper internal damage.
The client decided not to wait for a more serious failure and commissioned a full verification. The decision turned out to be correct – the earlier we detect problems, the lower the repair cost.
Construction of the A11V130 pump – what can wear out?
A11V130 series pumps have a basket mechanism also known from A4 models, which can be prone to wear.
It often leads to the formation of pitting on the swash plate and wear of the pistons or separator, which negatively affects the efficiency of the entire system.
Disassembly and verification of components
After removing the regulator and closing screws, we proceeded to separate the pump housing.
We carefully checked the reader, control pistons, and rotary group. To our surprise – despite the leaks – we did not record any burnouts or internal damage. The parts were in surprisingly good condition, so only the seals needed to be replaced.
Assembly with attention to every detail
We used a new seal kit and began assembly. The rotary group was carefully assembled – ball, separator, and then seated in the housing with original bumpers. All screws securing the separator bracket were secured with glue to prevent loosening during pump operation.
In the subsequent stages, we assembled the swash plate, control pistons, regulator, and sealing cover.
Testing and calibration – the most important stage
After assembly, the pump was mounted on the test stand. Before starting the test, we carried out the bleeding procedure – crucial for the proper functioning of the system. We then checked the tightness and the pump's response to external control signals.
During the tests, we could observe how the LS signal affects pressure and performance – the absence of this signal prevents the pump from operating.
Conclusions and recommendations
The A11V130 pump, although quite advanced in design, can operate reliably for a long time – provided that regular inspections are conducted and the first signs of problems are addressed.
Even seemingly minor leaks can be the beginning of more serious faults if not diagnosed in time.
The entire video can be seen here.
