TROUBLE |
PROBABLE CAUSE | REMEDY |
ERRATIC OR SLUGGISH OPERATION |
Rock drill
oil is heavy, gumming the
valve and slowing valve action |
Use oil of
the proper viscosity |
Gummed oil or dirt in operating parts | Disassemble, clean and examine parts for damage. Use clean oil from clean containers. Plug openings into the drill with rags when moving or storing the drill. | |
Stuck or broken operating parts | Disassemble and inspect parts. Replace damage parts. Clean all parts thoroughly. | |
DRILL LACKS POWER |
Short steel
shank or drill piston has been shortened through wear or regrinding of the
striking face. |
Check drill
shanks to ensure the length below the collar is 4 1/4”.
Grinding of striking face should shorten overall piston length a
maximum of 1/8”. |
Air screen plugged with dirt. | Check air connection screen regularly. | |
Restrictions in hose or pipe line. | Check air lines for obstructions (bend in hose). | |
Low air pressure. | Air pressure should be a minimum of 80 psi at the drill site, and of sufficient volume, 250cfm. | |
Lack of lubricating oil. | Fill oil line lubricator at beginning of the shift and check half-way through shift. Proper lubrication is demonstrated by “oil-wetting” of the drill shank. | |
Loss of cushion: worn buffer ring lining, worn piston or cylinder lining | Check condition of parts, replace damage or worn parts. Check for lack of lubrication. | |
SLOW DRILLING SPEED |
Low air
pressure. |
Air pressure should be a minimum of 80 psi at the drill site, and sufficient volume 250cfm. |
Cuttings not being removed from hole. | Adjust direct blow to remove cuttings. | |
Plugged drill steel or water tube. | Clean out drill steel and passage in the drill bit, otherwise bit will overheat and be ruined. Avoid crowding (over feeding) drill. | |
Drill not aligned with hole, steel binding in hole. | Check alignment while drilling, this is important to prevent binding of working parts and to avoid stuck drill steel. | |
Plugged air screen. | Clean screen regularly. | |
TROUBLE |
PROBABLE CAUSE | REMEDY |
DRILL DOES NOT ROTATE OR HAS WEAK ROTATION |
Loss of bit
gauge causing binding in the hole. |
Gauge grind
bits, replace worn out bits. |
Ratchet pawls worn, slipping in ratchet ring. | Turn pawls over in rifle bar, or install new pawls. Check tension of pawl springs. | |
Rifle nut badly worn. | Install new rifle nut. Check lack of lubrication. | |
Rifle bar badly worn. | Install new rifle bar. Check lack of lubrication. | |
Worn chuck driver. | Install new chuck driver. | |
Piston flutes badly worn or chuck driver nut worn. | Replace piston and/or chuck driver nut. Check for lack of lubrication. | |
Side rods tightened unevenly, piston binding in chuck driver. | Tighten side rods uniformly. Chuck parts should turn freely by hand in assembled drill. | |
Lack of lubrication front end. | Check line oiler for proper function. Should dispense one pint of oil every 6 hours. | |
CUTTINGS NOT BEING REMOVED FROM HOLE |
Plugged
drill steel or water tube. |
Clean out
drill steel and passages in the drill bit.
Use feed pressure cautiously in soft formations. |
Low water pressure. | Check water line restrictions. Crimped hose. | |
MUFFLER FREEZING |
Excessive
moisture in air supply. |
Blow out air
lines, increase oil flow from air line lubricator.
Install water traps in air supply line. Drain existing water traps. |
Water leak into air line due to faulty seams in pipeline. | Replace defective pipe coupling seals. | |
Broken water tube in rock drill. | Install new water tube in rock drill. | |
TROUBLE |
PROBABLE CAUSE | REMEDY |
DRILL OVERHEATS |
Lack of
lubrication. |
Check
function of line oiler. Clean
out oil reservoir and fill line oiler regularly. |
Wrong type of oil. | Check specification of oil supply, use rock-drill oil suited to ambient temperature. | |
Machine allowed to run with insufficient feed pressure, allowing piston to build up cushion between piston and striking bar, heating up the front end of the drill. | Increase feed pressure when drill rods are “free-wheeling” (turning excessively fast). Decrease feed pressure when drill rods are binding or sticking in the hole. | |
Pulling steels with rock drill in full throttle, builds up cushion in the front end of the drill and drill overheats. | Use as little throttle as necessary to loosen the drill steel when pulling out of a completed drill hole. | |
STUCK
DRILL
STEEL |
Water
pressure too low. |
Check water
line restriction, crimped hose. |
Drilling with dull bits or bits with poor gauge clearance. | Use sharp bits with proper gauge clearance. | |
Crowding (over-feeding) drill steel in soft rock formation. | Set the leg feed pressure lower in softer rock formations. | |
Drill cuttings not being removed. |
Stop and
blow hole if drop in water
volume exiting hole is noticed. Clear
cuttings.
|
|
Steel binding in hole due to misalignment of drill rods. | Check drill alignment often during drill cycle. Adjust feed pressure to maintain direction. | |
Plugged water tube or drill bit. | Clean out water tube and drill bit or steel. | |
FOGGING FROM ROCK DRILL EXHAUST |
Broken water
tube. |
Replace
water tube. |
Excessive water in air supply. | Blow out air lines, drain water from traps in supply lines | |
Excessive lubrication | Adjust feed of air line oiler. Check viscosity of rock drill oil against ambient temperature | |
TROUBLE |
PROBABLE CAUSE | REMEDY |
DRILL WILL NOT START |
Dirt in
automatic valve assembly, valve gummed by oil. |
Send drill
to drill shop. Dismantle
drill and clean automatic valve and air passages. |
Auto-valve flooded by oil. | Use rock drill with viscosity suited to ambient temperature of work site. | |
Plugged
exhaust ports. |
Check material plugging ports, check for excess water, rust, scale or dirt in air lines. Drain water traps, blow hose. Place on cup of oil in intake air hose and blow drill. | |
Frozen muffler. | Drain water traps in air line, blow hoses. | |
Plugged air screen or air passage. | Check air intake screen for pipe rust, scale or dirt, or gummy oil. Use correct rock drill oil, blow air lines. If drill will still not start return to shop to be dismantled. | |
Stuck or seized piston. | If piston does not come free, check outside of drill cylinder for hammer marks, dents and/or dents in housing. If detected return to drill shop for repair | |
PISTON CYLINDER BUFFER RING SCORED |
Side rod
tightened unevenly binding of parts in the rock drill. |
Replace any
damaged parts, and tighten side rods evenly. |
Insufficient lubrication. | Make sure air line oiler is installed no more than 12’ from drill, and check feed rate of oil and functioning of the line oiler. | |
STUCK
OPERATING
PARTS. |
Dirt
has entered drill from air line. |
Disconnect
air feeder hose, and blow air lines.
Clean screen in air intake. Take
care when connecting hoses to keep dirt out. |
Dirt has entered drill through exhaust ports while in storage. | Take care storing drill between use, do not throw in muck pile. Interconnect hoses and place oiled rag in chuck for storage. | |
Gummed or dirty rock drill oil. | Clean lubricator fill plug before removal, and fill with clean oil. Recap lubricator when full. | |
Piston cylinder bore or buffer ring liner scored. | Send drill to shop, check cylinder for damage, replace if necessary. Always install a new piston in a new cylinder. | |
TROUBLE |
PROBABLE CAUSE | REMEDY |
PISTON CHIPPED OR BROKEN |
Buffer ring
lining worn, piston not hitting drill steel squarely. |
Install new
buffer lining, replace piston. Check
squareness of ends drill shanks. |
Worn chuck parts, caused by poor alignment of steel with the hole. | Replace worn parts and piston. Check the squareness of the ends of drill steel shanks | |
Insufficient lubrication or wrong type of lubricant. |
Check specifications (viscosity) of oil used. Set line oiler to proper flow rate. Replace piston and any damaged parts. |
|
Side rods not tightened evenly, piston binding in chuck nut. | Replace piston, tighten side rods alternately and uniformly. | |
BRONZE CUTTINGS IN WORKING PARTS OF ROCK DRILL |
Rifle bar
flutes worn cuts rifle nut. |
Replace
rifle bar and rifle nut. Check
cylinder bore for scoring or other damage. |
Side rods not tightened evenly causing binding and scoring of rifle nut or chuck driver nut.. | Replace damaged parts. Tighten side rods alternately and uniformly. Check cylinder for damage if bronze is found in the piston travel area. | |
Rifle nut or chuck driver nut worn or damaged from insufficient lubrication. Nuts appear burned (blackened). | Check functioning of the air line oiler, check oil specifications. Replace damaged parts. Check drill cylinder for damage, if bonze is found in the piston travel area. | |
EXCESSIVE WEAR OF ALL PARTS |
Faulty or
insufficient lubrication. |
Check
cylinder bore for excessive wear, replace if necessary, replace all
affected parts. Check air
line lubricator for proper installation (12’ from drill), proper
function, and flow rates. Clean
lubricator fill plug before removal, and fill with clean oil.
Promptly recap lubricator when full. |
Dirt or grit in working parts causing scoring, and/or premature failure of parts. | Check cylinder bore for damage. Replace all damaged parts, clean remaining parts in clean solvent, coat with oil before replacing in drill. Plug all openings into drill with oiled rags, interconnect hoses before putting machine in storage, or returning to work site. | |
TROUBLE |
PROBABLE CAUSE | REMEDY |
PISTON CYLINDER OR BUFFER RING SCORED |
Side rods
tightened unevenly, causing binding Faulty or insufficient lubrication. |
Check
cylinder bore, replace if necessary, replace damaged parts, tighten side
rods alternately and uniformly. Check
cylinder bore for excessive wear, replace if necessary, replace all
affected parts. Check air
line lubricator for proper installation (12’ from drill), proper
function, and flow rates. |
EXTENSIVE DAMAGE TO ROTATING PARTS | Cylinder bore, buffer ring or piston badly worn causing loss of air cushion in piston travel, lack of compression and piston striking bottom on buffer ring assembly. | Replace
badly worn or damaged parts. Never
run rock drill once the air cushion is lost in piston travel area, due to
lack of compression. Serious
damage to drill cylinder, front end and major components of rock drill
will results from continued operation. |
TROUBLE |
PROBABLE CAUSE | REMEDY |