Quick answer: maintain a YT-series air-leg rock drill as a controlled system—not as a machine that is opened only after performance drops. Before each shift, identify the exact drill and air-leg configuration, inspect the external air, water, lubrication, support and drill-string paths, then record a controlled functional check. After the shift, isolate and depressurize the system, manage contamination and carry every unresolved defect into a work order.
Open the one-page shift checklist
Which machines this checklist can cover
The workflow can organize maintenance records for YT24-, YT27-, YT28- and YT29A-class air-leg rock drills, but it does not make their internal parts, operating limits or service intervals identical.
| Current PerfoMax family | Use this page for | Confirm separately |
|---|---|---|
| YT24 series | External condition, system-path and shift-record checks | Exact YT24C/TY24 identity, manufacturer, manual revision and approved air-leg pairing |
| YT27 | External checks and condition trend recording | Exact supplier configuration, limits, internal service tasks and parts |
| YT28 | External checks before using the dedicated YT28 diagnostic pages | Exact maker/revision, air leg, air/water condition, lubrication and drill-string interfaces |
| YT29A | External checks and working-envelope records | Exact maker/revision, complete air-leg suffix and model-specific maintenance instructions |
Before pressurization: seven external checks
| Check | Normal signal | Abnormal signal | Next step |
|---|---|---|---|
| Identity and open defects | Exact model, maker, air-leg suffix and controlled manual are recorded; no unresolved hold | Identity/revision unknown or an earlier defect has no disposition | Keep isolated; identify the equipment and close the hold before use |
| Body, guards, fasteners and controls | No visible crack, looseness, missing protection or damaged control | Crack, deformation, missing/loose item or control that does not return correctly | Tag out and send for qualified inspection; do not improvise a repair |
| Air hose, couplings and restraint | Correctly rated, clean, secure and free of obvious damage or leakage risk | Cut, bulge, damaged fitting, forced adapter, loose locking or missing required restraint | Replace or correct before pressure; use the approved hose/coupling arrangement |
| Air and water circuits | Every port is identified; paths remain separate; flushing route is open | Unknown port, cross-connection risk, blocked flushing or contaminated connection | Stop and identify the correct circuit from the exact drawing/manual |
| Oiler and lubricant | Correct lubrication architecture and oil are confirmed; delivery can be verified | Wrong/unknown oil, empty/blocked/reversed oiler or no reliable delivery signal | Do not run dry or guess a setting; use the lubrication guide and exact manual |
| Air leg and mount | Complete suffix, mounting, controls and working geometry are approved and secure | Loose mount, damaged lock, unknown suffix, hose problem or unstable support | Keep depressurized; verify the configuration or use the air-leg troubleshooting path |
| Drill steel, shank, bit and retainer | Correct interfaces, secure retention, straight serviceable steel and open flushing holes | Mismatch, deformation, looseness, damaged retainer or blocked flushing | Remove the affected tooling from service and verify every interface |
Controlled function test: record the loaded behavior
Pressurize and start only under the approved site procedure. A compressor gauge or an idle test does not replace observation at the operating drill.
| Check | Normal signal | Abnormal signal | Next step |
|---|---|---|---|
| Dynamic air condition | Tool-inlet condition remains within the exact configuration’s approved range under the planned load | Pressure collapse, unstable branch or major difference between idle and loaded behavior | Stop increasing settings; inspect the air path, simultaneous load and compressor capacity |
| Leak, sound and temperature | No material leak; sound and housing temperature remain normal for the known machine | New leak, harsh/uneven sound, rapid temperature rise or material change from baseline | Stop, isolate and record the location/time; route to model-specific diagnosis |
| Percussion and rotation | Stable response without forcing controls or compensating with excess pressure | Weak/irregular impact, poor rotation, hard starting or unexplained air use | For YT28 use the dedicated troubleshooting sequence; otherwise use the exact manual |
| Air-leg feed and support | Controlled extension/feed, stable support and no continuous abnormal leakage | Won’t extend, slips, jumps, binds, leaks or loses controlled feed | Stop and use the pneumatic air-leg troubleshooting guide |
| Flushing and lubrication signal | Flushing remains stable and lubricant delivery matches the exact manual | Weak/backflowing water, water in an unknown path, dry running or excessive/uncertain oil | Stop; separate the water and lubrication faults before further operation |
After the shift: close the loop
| Check | Normal signal | Abnormal signal | Next step |
|---|---|---|---|
| Controlled shutdown | The exact manual/site sequence is followed; energy is isolated and pressure released before connection work | Residual pressure, uncontrolled movement or uncertain shutdown state | Secure the area and restore the approved isolation procedure |
| Clean, drain and dry | Cuttings, dirt and moisture are managed by the approved method without forcing contamination inside | Blocked opening, standing moisture, condensate problem or contaminated lubricant | Keep out of service until the contamination source and safe cleaning method are confirmed |
| Wear and leakage trend | No new damage; previous readings/observations remain stable | New wear, repeated leak, faster deterioration or the same defect on multiple shifts | Photograph, tag and open a work order; do not reset the checklist to zero |
| Storage protection | Clean, dry storage and protected openings as required by the exact manual | Tool placed in cuttings/water or ports left open to contamination | Correct storage before leaving the equipment |
Schedule deeper work by the correct trigger—not invented hours
Use the applicable manual and site plan to define when a qualified person checks measured wear, clearances, internal condition, lubrication suitability, seals and replacement parts. Record the trigger and source beside the work order. Shorten or revise the plan when utilization, dust, moisture, temperature, upward drilling or repeated defects justify it; do not silently copy the Y19A 8/40/200-hour routine to the YT family.
What to photograph and record with a defect
- full machine, complete model/manufacturer identification and air-leg suffix;
- the exact damaged/leaking area plus a wider context photo;
- air and water ports, hose/coupling/lock/restraint arrangement before disconnection;
- oiler model, direction, lubricant label and observable delivery condition;
- drill-to-leg mount, controls and working geometry;
- shank, drill steel, retainer, bit and flushing openings;
- loaded tool-inlet reading, compressor/header reading and simultaneous users;
- shift, approximate service history, symptom, operating direction and the condition when it started.
When external checks do not explain the symptom
Do not turn a shift checklist into an uncontrolled teardown. If the supply, connections, lubrication, water path, air leg and drill string pass but impact/rotation, heat, leakage or starting remains abnormal, isolate the machine and send it to qualified workshop inspection using the correct manual and parts information.
Stop, isolate and tag out when
- a pressure-bearing component, hose, coupling, lock or required restraint is damaged, loose or outside its rating;
- the air leg moves unexpectedly, cannot hold controlled support, binds or leaks seriously;
- impact/rotation becomes abnormal, temperature rises rapidly, sound changes materially or lubrication cannot be confirmed;
- water enters an unconfirmed port, flushing fails or contamination reaches the pneumatic/lubrication path;
- the shank, drill steel, bit or retainer is mismatched, cracked, loose, badly deformed or ejecting debris;
- the equipment identity, manual revision or required return-to-service authority cannot be confirmed.
Send the symptom to the correct technical owner
- Lubrication, line-oiler and oil-delivery checks
- Air leg won’t extend, slips, leaks or feeds poorly
- YT28 slow drilling, weak impact, poor rotation or hard starting
- YT28 weak flushing, backflow or water-path concern
- Air-hose ID, length, coupling bore and dynamic pressure
- Air-inlet thread, coupling and adapter compatibility
Product and service paths
Confirm the current product identity before asking for parts or replacement: YT24 series, YT27, YT28 or YT29A. You can also browse the Air-Leg Rock Drills Collection.
For a maintenance, parts or replacement review, send the completed checklist, machine identity, photos, loaded air condition, symptom and quantity. PerfoMax can then respond against a defined configuration rather than the YT family name alone.
Frequently asked questions
Can I use the Y19A 8/40/200-hour schedule for a YT28?
No. Those intervals belong to cited Y19A instructions. Use the exact YT28 manufacturer/revision manual and your approved site maintenance plan.
Does this checklist replace the rock-drill manual?
No. It organizes external checks and records. The exact manual controls operating limits, inspection intervals, disassembly, tolerances, parts and return-to-service work.
Should I open the valve chest when a shift check fails?
Not from this page. Stop, isolate and document the failure. Internal inspection should be performed by a qualified person using controlled instructions for the exact machine.
What is the most important maintenance record?
The complete equipment identity plus the change from its known normal condition. A pressure, leak or wear note without model, time and operating context is difficult to act on.
Can one checklist cover YT24, YT27, YT28 and YT29A?
It can provide a common external-check and record structure. It cannot make their model-specific limits, parts, intervals or internal procedures interchangeable.