APT MH 11, Safety & Operating I

Page: 20 / 28

20 (doc no.)
MH 11, 55, 55a, 70, 70a SAFETY & OPERATING INSTRUCTIONS
Technical data
Troubleshooting
Solution Cause Problem
Check flow/pressure by means of test
equipment
No or incorrect flow/pressure Breaker does not work. Pressure is not built
up when trigger is activated
Check connection. Standard connection has
oil flowing from male quick-release coupling
(i.e. the tail-hose of the breaker P connection
is fitted with female coupling)
P and T hoses interchanged
Adjust trigger lever (if adjustable) or replace
defective parts
Insufficient activation of trigger valve
Dismount, check and replace seals Diaphragm failed
Make direct tank connection. Max. back
pressure 10-15 bar (150-200 psi) measured
at breaker
Back pressure too high Breaker does not work. Pressure is built up
when trigger is activated
Locate and replace defective coupling Quick-release coupling in return line
defective
>
Push the breaker hard against the
working tool
>
Chamfer/polish the edge slightly at the
cylinder dashpot (where the cylinder bore
changes size)
>
Check oil viscosity. Thin oil increases the
risk of thickening
Striking piston sticks, possibly due to
thickening of cylinder
Dismount and check that all parts move
easily. Polish slightly if necessary
Spool/reversing spool or auxiliary spool
sticking
Dismount, check and replace Seals defective
Check flow/pressure Insufficient flow Breaker runs weakly or irregularly
Replace seals Seals defective
> Dismantle, check and replace defective
or worn parts
> Check oil for impurities and oil viscosity
at working temperature
> Thin oil = increased internal leakage
Wear, internal leakage
Replace accumulator diaphragm and charge
with nitrogen
Accumulator defective Hoses pulsate
Replace seals Seals defective Oil leaking from breaker
Replace latch and roll pins Worn latch Working tool falls out
Replace bushing or tool Worn chisel bushing or tool
Machine data
EHTMA
Category
Flow rate
(l/m)
Operating
pressure
(bar)
Accumulator
pressure
(bar)
Impact
freq.
(Hz)
Length
(mm)
Weight
(kg)
Shank
dimension
(mm)
C 18-22 70-90 40 40 600 12.6 22 x 82.5 BRK 25 D
C 18-22 95-115 40 27 640 17.5 25 x 108 BRK 40
C 18-22 95-115 40 27 690 19 28 x 160
C 18-22 95-115 40 27 690 19 32 x 152
C 18-22 95-115 40 27 690 19 32 x 160
C 18-22 95-115 40 27 650 22 25 x 108 BRK 40 VR
C 18-22 95-115 40 27 700 23.5 28 x 152
C 18-22 95-115 40 27 700 23.5 32 x 152
C 18-22 95-115 40 27 700 23.5 32 x 160
3392 5166 01 | Original instructions 20
BRK 25, 40, 55, 70, 95 Safety and operating instructions