18
PROBLEM
CAUSE
REMEDY
Low
penetration/
high pressure
5. Exhaust tube projection
too long
6. Valve action impeded
7. Worn Tail Seal
5. Check projection vs. specifications repair tube.
6. Check nose of backhead for corrosion other deposits that can interfere with the
smooth cycling of the valve. Remove deposits if present.
7. Replace Tail Seal.
Low
penetration/
low pressure
1. Lack of oil
2. Worn drill clearances
3. Damaged valve seat
4. Incorrect Airselect setting
1. Insure lubricator is working and hammer is getting coated
with oil. Check bit blow ports for oil film.
2a. Inspect piston for wear particularly on large diameter just beneath scallops.
This is the most sensitive diameter. Check other diameters; tail bore seal and tail
diameter for wear. Compare all to specification.
2b. Inspect guide diameter for wear. Compare with
specification and replace if necessary.
2c. Check cylinder bore for wear. Compare to
specification and replace if necessary.
2d. Check casing bore for wear. Compare to
specification and reverse or replace if necessary.
2e. Check bearing bore for wear. Compare to
specification and replace if necessary.
3. Inspect valve seat surface for damage or wear
which could cause leakage. Replace valve is suspect.
4. Readjust Airselect.
Drill running
off bottom
1. Worn piston
2. Excessive water injection
3. Debris (cuttings, mud)
between chuck and bit spline
1. Inspect large diameter of piston for wear. Leakage past the large diameter can
cause the piston to cycle when off bottom.
2. Try reducing water injection level. Water inhibits the air venting process which
is needed to shut the hammer off.
3. Clear debris.
Chuck hard to
loosen
1. Poor gripping
2. Conditions
1a. Don´t grip over threads.
1b. Insure tong jaws are sharp.
2. Try using breakout washer.
Compressor
unloading
1. Incorrect Airselect setting
2. Excessive water injection
3. Mud Rings
1. Correct Airselect setting.
2. Reduce water injection rate.
3. Clear mud ring. Increase water injection. Consider adding foam.
Hammer
won’t start
1. Mud or dirt in hammer
2. Broken exhaust tube
3. Broken internal parts
1. Disassemble, clean, inspect and repair hammer. Check for
proper function of check seal.
2. Replace tube. Inspect Bearing and Chuck.
3. Replace broken parts.
Component
failures
1. Piston cracked through
1a. Lack of lubrication could cause frictional cracks in large diameter.
Check
lubricator and insure oil film is developed on
bit blow holes.
1b. Wrenching over wrong location distorts casing and causes frictional rubbing
with piston. Apply tong wrench pressure in correct location.
1c. Fighting or getting stuck in hole heats and distorts casing bore causing
frictional heat and cracks on piston. Flood tool with water when stuck.
1d. Collaring on an angle or feeding hard through voided, faulted or broken
ground can cause casing to distort and rub piston causing cracks. Use light feed
when going through tough conditions.
