Said in other words. Thread is a cylinder head around 20 in length (28 mm as shown
picturenr.3) and sediment - corroded joint 32 mm.
Such a large rust resistor cannot be overcome to release with 13 mm sockets and in most cases
tear off the head bolts in all 4 injector holders also the new vehicles.
The follow drilling out process is very complicated because the bolt is made by rolling the
compacted material especially at the point of the thread, between the beginning and the bolt
body. (Bolt hardness 10.8).
Inproper free drilling out done by hands in wrong speed without cooling and without
removing chips also with inaccuracies drill heads almost always results in imprecise drilling
and break the cylinder head wall. So it should not fully drill out of original thread or drilling
the water canal, which is located just below the end of the bolt.
Drilling out broken stud takes three hours also for manualy operation skillfully workers, (for
all four injectors 12 hours).
Mechanics also make this operation simpler. Work can be fastening by drilling stud the
injector after removing the cylinder head. It brings with additional time and costly action such
as
draining
coolant,
replace
head
gasket
and
others.
When stud is drilled out, the tolerance goes away. Injector retaining bolt has original thread
M8x1,25. It is insufficient and therefore it is necessary to stocking threaded inserts "Helicoil"
(spring system). Mechanics facilitate their work and incorrectly insert coil into the camshaft
cover because of elaborateness and complexity of the operation. But it is wrong.
Solution
The solution to this issue is The drill out device - manufactured by Triumf with order number
24952.
Picture 4.
Injector fixing bolt Fiat Ducato HPi 3.0l
Picture 5.
Body of drilling out mechanism from set 24952
