REF. A03 Blast Machine Maintenance

Troubleshooting TLR Remote Controls and Classic Blast Machines

This guide condenses Section 7.0 of Clemco Manual 22501 — troubleshooting for 2–20 cuft Classic blast machines with TLR-100/300 pneumatic remote controls. It identifies the likely cause; always refer to the manual's service sections before opening anything up.


1. Safety First

When troubleshooting: turn off the compressed air and lockout/tagout the air supply. When a check requires air, always enlist a second person to operate the control handle while you hold the nozzle securely, pointed in a safe direction. Never strap the control handle lever down in the operating position.

2. Abrasive-Flow Problems

Clemco Manual 22501 — Classic Blast Machine with TLR-100/300 Remote Controls (Rev I)
SymptomCheck, in order
Nothing exits nozzle (machine pressurized)Nozzle obstructed — depressurize, wait for the pop-up to drop, remove and check the nozzle. Then confirm the metering valve and choke valve are both open.
Air only, no abrasiveMetering valve closed or needs adjustment; machine empty; abrasive damp (clear per the choke-valve procedure); obstruction in the metering valve.
Heavy abrasive flowChoke valve not fully open (handle must be in line with the piping); metering valve open too far.
Abrasive surgingModerate surge at startup is normal. If it continues: reduce the metering setting; check the abrasive trap and exhaust muffler for blockage — slow depressurization loads the blast hose with abrasive and causes surging at startup.
Intermittent flowMoisture in the machine or air supply — drain the compressor receiver and the machine's air filter; persistent moisture may need an aftercooler or air dryer. Abrasive may be too fine or worn from recycling — replace it.

Table 1 — Abrasive-flow symptoms and causes, from Sections 7.1–7.5 of the manual.


3. Machine Does Not Pressurize

Work through these in order:

  1. Compressor ON and all air-supply valves to the machine open.
  2. Safety petcock on the inlet valve closed.
  3. Rubber button on the control handle in good condition and sealing the opening when the lever is pressed.
  4. With the lever up, air should escape from the opening under the lever. No air escaping means the 1/16″ orifice on the inlet valve is blocked, or the line from the orifice to the handle is blocked.
  5. Press the lever and listen for leaks at the handle, control lines, and fittings — once the handle is pressed there should be no air leaking anywhere in the controls or machine.
  6. Open the petcock and press the lever: the same volume of air should exhaust from the petcock as before the lever was pressed. If not — check for a sealed-off handle opening, control-handle leaks, a blocked line to the inlet valve's upper fitting, or a split diaphragm (diaphragm outlet valve machines). If air volume is fine, the inlet valve itself needs service.
  7. Close the petcock, press the lever, and check the vent hole in the inlet valve's cylinder body — air escaping the vent means a worn piston or piston O-ring.
  8. Still nothing? Compressor may be too small for the nozzle, the air-supply hose or fittings undersized, the optional air filter element dirty, or the pop-up valve stuck / internal piping worn or misaligned.

4. Machine Does Not Depressurize (or Too Slowly)

  • Abrasive trap screen blocked or trap full — inspect the screen and empty the trap (this should happen at least twice daily).
  • Exhaust muffler blocked — inspect and service; replace the element body.
  • If the machine does depressurize but control air remains in the lines: check the handle's pneumatic adaptor gasket for swelling, the exhaust opening in the handle for obstruction, the control hose for blockage, and the lower inlet-valve fitting — it must be the 1/16″-orifice fitting, not a full-flow fitting.
  • If the machine does not depressurize: the inlet valve isn't fully closing or the outlet valve isn't fully opening — service the valves. On diaphragm outlet valves, a diaphragm that has taken a set toward the machine can be reversed.

5. Outlet Valve Leaks While Blasting

The outlet valve requires service — piston valves per Section 6.4 of the manual, diaphragm valves per Section 6.5. Common findings inside: worn piston cup, abraded piston rod, worn valve plug and washer, or a spring past its length spec (piston outlet valve spring is approximately 1-5/8″).


6. ACS Problems

  • No abrasive in blast mode: confirm the machine contains abrasive, the metering valve isn't closed, and the ACS toggle points ON (away from the nozzle); then check the single-line hose and fittings from handle to metering valve for leaks or blockage; finally, the metering valve may need service.
  • Abrasive doesn't stop in blowdown mode: the brass filter on the ACS switch is clogged, or the metering valve requires service.
Fix leaks, don't watch them. Nearly every remote-control fault traces to a leak, a blocked orifice, or a dirty trap/muffler. All three are cheap to fix — and all three get worse fast.