51991057_ed3
5
Trouble
Probable Cause
Solution
Jackhamer lacks
power
Low air supply pressure.
The air supply pressure at the inlet should be 90 to 100 psi (6.2 to
6.9 bar).
Running on fronthead cushion.
Keep shank fed-up to the work. Always maintain a constant
pressure when operating the Jackhamer.
Plugged air passages.
Dismantle the Jackhamer and clean out all ports and passages.
Lack of lubricating oil.
Maintain the proper oil level in the air line lubricator. Steel shank
must show a
fi
lm of oil.
Short Drill Steel shank due to wear or
regrinding.
Replace Drill Steel if shank is worn excessively.
Worn components.
Check and replace parts that show wear.
Jackhamer will not
start
Plugged exhaust port or air passages caused
by dirt or hose particles.
Dismantle Jackhamer, clean out all ports and air passages. Keep the
air hose in good condition; never use a soft deteriorated hose.
Excessive moisture in the air supply line.
Blow out air lines. If moisture traps are installed in the air supply
line, drain the moisture.
Over lubrication.
Adjust the air line lubricator for proper rate of feed.
Overheating of
Jackhamer
Running on fronthead cushion.
Keep shank or hammer block fed-up to work. Always maintain
constant pressure when operating the Jackhamer.
Lack of lubrication or improper lubricating oil.
Before operating the Jackhamer make sure the air line lubricator is
full of proper lubricant.
Piston not hitting the shank because of short
shank.
Remove the Drill Steel with the short shank from the Jackhamer and
install a new Drill Steel.
Pulling Drill Steel at full throttle.
When pulling Drill Steels, always use minimum throttle.
Erratic or sluggish
operation
Lubricating oil too heavy.
Use only the recommended lubricating oil.
Gummed oil or dirt in operating parts.
Dismantle Jackhamer and clean out dirt and gummy residue.
Service the Jackhamer with clean oil. Protect the Jackhamer from
dirt when idle.
Stuck Drill Steel
Driving Drill Steel after bit is dull or has lost
its gauge.
Sharpen or replace with a new bit.
Crowding bit in soft formation.
Use down pressure cautiously in soft formations; be certain the Drill
Steel is rotating freely.
Cuttings not being blown from hole.
Use blow air frequently.
Misalignment of Drill Steel with hole causing
binding.
Keep Jackhamer, Drill Steel and hole in alignment at all times
Slow drilling speed
Dull bit.
Replace the bit.
Cuttings not being removed from hole.
Use blow air more frequently to keep the bit working on fresh rock.
Plugged Drill Steel or Blow Tube.
Remove Tube and Drill Steel; clean out air passages.
Jackhamer and Drill Steel not aligned in hole;
Drill Steel or bit binding in hole.
Check alignment while drilling to prevent binding and to avoid a
stuck Drill Steel.
Insu
ffi
cient down pressure.
Increase down pressure.
No Drill Steel rotation
or rotation is weak
Steel binding in hole.
Apply correct amount of down pressure and keep Drill Steel and
hole in alignment. Replace worn bits.
Worn rotation parts.
Disassemble Jackhamer and replace worn parts.
Side Rod breakage
Uneven tension on Rods or loose Rods.
Keep Side Rods tight and at even tension. Tighten Rods alternately.
Loss of fronthead cushion which allows Piston
to strike Front Washer Bushing with hard
impact.
Replace worn Cylinder, Piston or Front Washer Bushing.
Chipping or breakage
of Piston
Bad Drill Steel shank which is too hard or
rounded on end allowing minimum contact
with Piston striking face.
Take bad shanks out of service. One bad shank can ruin many
Pistons.
Worn Chuck which permits Drill Steel to cock
in Chuck so that Piston strikes shank a glancing
blow.
Replace worn Chuck.
Heat cracking due to faulty lubrication.
Keep Jackhamer well lubricated with proper type of oil.
Failure in neck of Piston due to loss of
fronthead cushion. Piston striking Front
Washer Bushing.
Check Cylinder, Piston and Front Washer Bushing for maximum
wear
tolerances.
Summary of Contents for Jackhamer JH40
Page 7: ...Notes...
