Trelawny VL203Ex, Operation And Maintenance Manual

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PAGE 8
VL303EX Chisel Scaler
MAINTENANCE
Maintenance must only be carried out by a competent
person, in a suitably equipped workshop.
Disconnect the tool from the air supply before carrying out
any of the following operations.
Clean all debris from the exterior of the tool.
This tool has been designed so that you only require a
vice, screwdriver, 3mm pin punch, 6mm allen key and light
hammer, no other specialist tools are required to completely
strip and service the tool.
For safe efficient running and at intervals of no more than 120
hours, dismantle and clean with highly refined paraffin.
Check all components for wear, replace the 6mm Ball (Item
17) and all O’Rings. Immediately after cleaning, thoroughly oil
the tool with one of the recommended lubricants.
Recommended lubricants
Oil the tool daily during use. Put a few drops of one of the
following bio-degradable air tool lubricants through the air
inlet.
SHELL Naturelle HF
CASTROL Carelube HTG 22
Always use clean oil from a sealed container and ensure
ignition temperature is above 185deg C.
Tool Dismantling
Before carrying out any dismantling, ensure the air supply
is turned off and remove the air-line from the tool. Clean all
deposits from the outside of the tool. Service kits are available,
see parts section.
Chisel Holder removal
Hold the Cover in a vice using the flats provided, keeping the
Chisel holder (37) vertical. Loosen Pinch bolt & Unscrew Anti
Clockwise by hand, remove the Chisel holder (37) complete
with the Spring (32) as an assembly.
Piston and Cylinder removal
Hold the Cover in a vice using the flats provided, keeping the
Chisel holder (37) vertical. Loosen Pinch bolt & Unscrew Anti
Clockwise by hand, remove the Chisel holder (37) complete
with the Spring (32) as an assembly.
Note: When removing tool from vice, do not point the front of
the tool downward; the piston may fall out of the Intermediate
Tube causing damage.
Hold a clean lint free cloth over the open end of the
Intermediate Tube, remove from vice and tilt the Tube
downwards to remove the Piston (26). Secure the Cover (10) in
a vice with the Intermediate Tube in the vertical position, using
the flats provided.
Use a suitable 6mm bar through the holes provided, unscrew
the Intermediate Tube (22) anticlockwise. Carefully remove the
Intermediate Tube from the cover and remove the Cylinder
from its location hole in the Cylinder Guide Plate, which is
fitted in the cover.
The Cylinder Guide Plate (12) can be pulled out of the cover to
gain access to the Guide Plate Seal (13).
Cylinder Ball Valve replacement
This is a consumable item and will require replacing after
approximately 120 -160 hours use; this is dependant on the
cleanliness of the air supply and frequency of lubrication.
Do not replace this plastic ball with a steel version, as it will
damage the cylinder valve seat and piston valve pin.
The ATEX certification will also become invalid.
Remove the ball retaining O’Ring (18) from its groove
just inside the bore of the stem using a suitable pointed
implement. Remove the ball from the bore or if it has worn
excessively and may have passed into the cylinder, check the
cylinder exhaust holes for the remnant also. Replace and refit
new O’Ring into groove.
Piston Valve Pin replacement
Hold the piston in a vice by the stem, using a pair of cutters
remove the top of the Valve Pin (28), using a drill & 6mm drill
bit and remove the remainder from the piston. A small socket
(4mm) which just fits over the actual pin, will stop damage
occurring. Drive the valve pin in up to its shoulder using a vice
or a small hammer.
Valve Body - Valve Stem removal
Hold the Valve Body (6) in a vice using the flats provided.
Using a 3 mm diameter punch, drive the Throttle Lever
retaining Spring Pin (8) out of the Valve Body (6) and withdraw
the Throttle Lever (7). Remove the Valve Cap with O’Ring (2),
Valve Spring (3), Valve Stem (4) and the Valve Seat O’Ring (5).
Valve Body removal
Remove the Chisel holder and Anvil and Return Spring as per
instructions. Replace the Chisel holder, onto the Intermediate
Tube and screw up until hand tight. Hold the Valve Body flats
securely in a vice, with the Cover (10) uppermost. Turn the tool
anti-clockwise around the Valve Body by holding the Cover
and Chisel holder, unscrew the Valve Body from the handle
until loose, remove from vice and finally unscrew by hand.
VERY IMPORTANT Before carrying out any dismantling,
ensuring the air supply is turned off,