Komatsu 830E-AC Shop Manual page 591

TROUBLE: Oil is Leaking Around the Pedal Base
Defective seal on top of brake valve.
TROUBLE: The Pump Cycles Too Often Or Low Pressure Warning Comes On At Low Engine RPM
Excessive internal leakage in a component.
Accumulator precharge too high or too low.
Brake Valve plumbed incorrectly.
Internal leakage in brake valve assembly.
Pump is worn.
TROUBLE: The Pump Cycles Too Often Or Low Pressure Warning Comes On At Low Engine RPM
Leak in charge system.
Accumulators precharge too high or too low.
Brake Valve plumbed incorrectly.
Internal leakage in brake valve assembly.
Pump is worn.
J04036
Replace the seal.
Check all steering and brake system components.
Check accumulator precharge.
Correct plumbing.
Replace brake valve assembly.
Rebuild or replace pump.
Check charge system.
Check accumulator precharge.
Correct plumbing.
Replace brake valve assembly.
Rebuild or replace pump.
Brake Circuit Check-Out Procedure J4-11