Trelawny SF3EX, Operation And Maintenance Manual

PAGE 8

SF3ex SCALING HAMMER

MAINTENANCE

Excessive operator pressure will not improve the tool 

efficiency but will cause premature tool failure and operator 

fatigue. Never allow the tool to run continuously whilst not in 
contact with the surface being prepared.

Please be aware: that this tool will reduce in power or stop 
working if the end cap (17) has become unscrewed.

Maintenance must only be carried out by a competent person. 
Disconnect the tool from the air supply before carrying out any 
of the following operations. Clean all debris from the exterior 
of the tool.

Recommended lubricants

Oil the tool daily before use. Put a few drops of one of the 
following zinc free air tool lubricants through the air inlet.

SHELL S22 or R10
CASTROL Hyspin ZZ32

Always use clean oil from a sealed container and ensure 

ignition temperature is above 185degC°.

Cleaning

At intervals of no more than 40 hours or if operation becomes 
unproductive and the piston shows signs of sticking, dismantle 

and clean with a highly refined paraffin.

Immediately after cleaning, thoroughly oil the tool with one of 
the recommended lubricants.

Head removal - Taper Fit (On site)

Lay the scaling hammer on a solid surface with the cutter 
head (27) facing uppermost. Place the head removal washer 
(32) between the cutter head and the body; insert the removal 
pin (31), into cutter head hole (refer to diagram for pictorial 
illustration). Wearing safety glasses and using a medium size 
hammer give a sharp blow to the head of the pin, which will 
release the cutter head from the piston.

Piston/Cylinder Assembly removal (Workshop)

Hold the scaler body (23) in a vice, using the flats provided and 

with the end cap uppermost. On triple scalers, secure the tool 
in a vice, clamping on all three cutter heads. Unscrew the end 
cap (17). Remove spring cap (19) and spring (18) from the end 
cap. From the bottom of the body, push up the cutter head to 
remove the piston assembly.

Head Removal - Taper Fit (Workshop)

Lay the piston and cylinder assembly on a solid surface with 
the cutter head facing uppermost. Place the head removal 
washer (32) between the cutter head and the cylinder; insert 
the removal pin (31), into cutter head hole (refer to diagram 
for pictorial illustration). Wearing safety glasses and using a 
medium size hammer, give a sharp blow to the head of the 
pin, which will release the cutter head from the piston. Inspect 
all components for wear, replace as necessary.

Valve body servicing (Workshop)

Clamp the handle (10) assembly firmly in a soft face jawed 

vice (valve body end) throttle lever upper most. Using a 3mm 
diameter pin punch, remove the throttle lever roll pin (8), and 
then remove the throttle lever (7). Rotate the tool 180 degrees 
in the vice to access the valve. Unscrew the valve cap (1) using 

a screwdriver, check the valve cap ‘O’Ring (2), remove the 
spring (3), push out the valve stem (4) and remove the ‘O’Ring 
(5). Check the valve and ‘O’Ring for wear.

Assembly (Workshop)

Before any assembly takes place, ensure all parts are clean 

and have a film of air tool oil lubrication unless otherwise 

stated. Avoid lubricating oil or grease contaminating the 
threads of the end cap (17), the threads within the bore of the 
bodies (23) and the tapers on piston and cutter heads. The 
end caps will require securing with a thread-locking adhesive. 

It is good practice to renew all ‘O’ Rings (2/5) and the brush 

seals (22). Replace any parts showing signs of wear; paying 
particular attention to the small bore of the cylinder.

Head Assembly - Taper Fit (On-Site)

Thoroughly clean around area of cutter head and piston. 
Remove all traces of debris/oil from the taper on the piston 
(20) and internal taper of the cutter head (25) by cleaning with 
suitable oil free solvent. Place the tool in a position where the 
end cap is on a solid surface; Select one of the cleaned new 
cutter heads and place onto the taper of the piston. Using a 
soft-faced hammer deliver a sharp blow to the cutter head.

Head Assembly - taper fit (Workshop)

Remove all traces of oil and dirt etc, from the taper diameter 
on the piston (20) and cutter head (25) by cleaning with 
suitable oil free solvent. Fit the piston into the cylinder (21) as 
shown in the service layout. Place the assembly onto a solid 

surface; fit a new brush-seal (22) over the piston and into the 

recess of the cylinder. Select one of the cleaned new cutter 
heads and place onto the taper of the piston. Using a
soft-faced hammer deliver a sharp blow to the cutter head.

Note: If you are re-fitting a used cutter head to the piston it 

is essential that the internal diameter of the cutter head is 
re-surfaced using a medium grade of emery cloth - this will 

ensure a good fit between cutter head and piston, do not 

use adhesive of any description on the taper. If the taper has 
expanded too much on the old cutter heads, they may not 
stay on the piston, replacements will be required.

Piston/Cylinder assembly (Workshop)

Lubricate the piston (20) and cylinder bore (21) and push the 
piston into the cylinder bore. Lay the tool on a bench with the 
body (23) on its side and insert the cylinder assembly into the 
body.