Cylinder Head Gasket - CITROËN Amicale 5 HP Manual

10 - CYLINDER HEAD GASKET

"The nuts of a cast iron cylinder head should always be loosened when cold and always tightened when hot.
(Otherwise guaranteed risk of cylinder head gasket leakage)
No paste needed, just a little linseed or engine oil. "
Apply these products in thin and even coats on both sides of the joint. Do not spread too thick a layer, these
ointments do not help to ensure the seal, they only serve to facilitate the correct installation of the gasket when
tightening the cylinder head.
10 a - Tightening the cylinder head:
When reassembling, take care to tighten the nuts in the following order:
PHOTO
Tighten the nuts by hand, then with a torque wrench, starting from the center and gradually moving away
towards the ends (like a snail). A cold tightening torque of 3 meter kilograms is usually sufficient.
"1st pass: 2 m.kg; 2nd pass: 2.5 m.kg; 3rd pass: 3 m.kg «... .. but reduce by 0.5 m.kg for the stud no.9 above
the carburetor (only 9 mm thread)
VERY IMPORTANT: For metalloplastic gaskets, several tightening operations are necessary before 'they don't
stabilize.
After a first light tightening, start your engine without water and let it heat up (your fingers are the
thermometer). Then stop.
Retighten. (Hot cylinder head) and let cool.
Fill your radiator, start up and let the temperature rise, make the third tightening.
After 500 KM, always hot, check the tightening again.
Take advantage of a gasket change to descale the combustion chambers and check the flatness of the gasket
face. It is also an opportunity to thoroughly clean the threads of nuts and studs.
Links & Documentation: '' Cylinder Head Gasket File ''
Doc: http: //www.precimotor.com/culasse.html
10 b- Cylinder head and block cleaning
Experience shows that today most cylinder heads and blocks are extremely, or even completely scaled up in
places such as the gallery above the valves.
During a restoration, it is imperative to dissolve the scale with hydrochloric acid (Beware!) To properly clean
the water chambers and to check that the water circulation is done between the 2nd and 3rd cylinder.
This is important for good cooling of the last two cylinders.
10 c- How to repair a crack?
In the past, there was only one remedy to seal: welding carried out by a specialist, a real professional job since
the entire block must be brought to high temperature in order to weld it and let it cool for several days.
Since then, current welding techniques, for example with TIG, have worked wonders.
An anti-leak product can give immediate good results in the case of leaks in chambers and water passages
without communication with "the fire" or a place subject to mechanical stress.
For a leaking cylinder head or block which lets the water slip through the oil (white mayonnaise at the end of
the dipstick) add a flask of Wondarveld to the cooling water.
It is an old product that is still commercially available.
But be careful, you must follow the instructions for use (this requires hours of heating up, stopping and
emptying successively).
Studs which are not screwed deep into the cast iron block also have an unfortunate tendency to "go up". For
the latter it is always possible to make a shouldered stud with a larger diameter which will solve the problem, or
preferably with threaded inserts "Heli-coïl".