5
en
Air Leaks
— at Valve Cap Assy (#23) Valve ring 0-ring (#24) damaged or
worn
Fit 0/H Kit #12552
Valve Cap 0-ring (#22) and/or (#18)
damaged or worn
Fit 0/H Kit #12553
— from trigger valve
0-ring (#36) and/or (#38) worn or
bushing assy (#35)
damaged
Fit 0/H Kit #12557
— at Trigger Valve Piston
(#37)
0-rings (#38) damaged or worn
Replace 0-rings. Fit 0/H Kit #12557
— between grip (#40) and
grip cover (#45)
Gaskets damaged
Replace gaskets (#42)
Screws (#58) loose
Tighten screws
— at Safety Valve (#54)
Piston Assy
0-rings (#55) damaged or worn
Fit 0/H Kit #12652
Trigger valve body 0-rings damaged
Fit 0/H Kit #12554
Trigger valve body defective (#56)
Replace trigger valve body assy.
— at nosepiece (#8) nail
exit
Damaged bumper (#12)
Replace bumper (#12) as necessary
0-ring (#14) damaged or worn
Replace 0-ring. Fit 0/H Kit #12552
0-rings (#18, #19) damaged or worn
Replace 0-ring. Fit 0/H Kit #12552
Tool will not fire
Air pressure too low
Check air source, regulator setting gauges,
hoses, fittings, etc.
Safety yoke (#1) stuck in down
Check for dirt or obstructions Replace
position
safety if deformed
— Driver Blade Assy (#16)
stuck down
Nails jammed in nosepiece (#8)
Clear jammed nail
Inspect Driver Blade and Nosepiece
Bent Driver Blade
Replace Driver Blade Assy (#16)
0-rings (#17) damaged or worn
Fit OH Kit #12657
Bumper (#12) severely damaged
Replace bumper
Defective trigger valve body (#56)
Replace trigger valve body assy
10. Instructions for disassembly of R4X12 S
(Use with Exploded View Drawings (2-4) and Parts list)
NOTE:
Before starting on the disassembly of the tool,
disconnect the tool from the air supply and remove all
fasteners from the magazine assembly. If handle grip
(40), plate (46), flange (10), and valve bushings (52, 59)
require service, contact your Hilti Representative.
10.1 Magazine assembly (48)
Release 2 nuts (66) using a 17 mm open end wrench
and 5mm Allen wrench. Remove hex socket screws (29)
and washers (61). Position pusher (47) in forward posi-
tion and remove magazine assembly (48) from nose-
piece (8).
10.2 Pusher (47) and grip (63)
Using a 2 mm pin punch, drive out spring pin (62).
Remove pusher (47) from magazine (48) by sliding for-
ward and away from magazine. Pull back grip (63) slight-
ly, align grip pin (65) with detents in magazine and tilt
back portion of grip up. Once grip pin (65) is clear of
magazine, tilt the grip (63) up and forward to clear the
scroll spring. If necessary, tap grip pin (65) out of bush-
ing (64) and grip (63). If the scroll spring (51) requires
replacement, contact your local Hilti Representative.
10.3 Safety yoke (1)
Remove 2 hex locknuts (3) using a 10mm open end
wrench and take off guide plate (2). Remove the safety
return spring (4). Remove the hex socket screw (5) clos-
est to Valve Piston Assembly (54) using a 5 mm Allen
wrench. It is not necessary to remove the nosepiece (8).
Slide out safety yoke (1) from Safety Valve Piston Assem-
bly (54).
Printed: 07.07.2013 | Doc-Nr: PUB / 5070503 / 000 / 00
