56 W arranty Guide The purpose of this guide is to provide advice on the correct application of Brunner Lay Demolition T ools and assist in analyzing and resolving any complaints immediately Cause and Ef f ect of F a tigue F ailur es The continuous cycle of compressive and tensile stresses in a Demolition T ool even under correct operating conditions creates fatigue stress in the tool which can lead to fatigue failure of the tool before it is worn out Anything which interferes with the normal operational cycle of compressive and tensile stresses will increase the level of fatigue stress being applied to the tool increasing the risk of early fatigue failure 1Le v er a g eBending The main cause of increased fatigue stress in a demolition tool is any form of side pressure during service which creates bending Utilizing the tool as a lever using the incorrect driving angle or attempting to break ground using the pull of the machine are all detrimental to the life of a demolition tool and are to be avoided see Figure 1 2F r ee R unningBlank F iring This can arise in any situation where the working end is not in proper contact with the material to be broken This includes jobs where the tool slides of f the work and also when breakthrough of thin concrete slabs or boulders occurs It is essential that the tool is applied at a rightangle to the working surface at all times 3Lubrica tion Regular lubrication is essential Any form of damage to the surface of a demolition tool renders it more liable to suf fer fatigue failure Care must be taken to prevent accidental gouging or contact welding galling or pickup due to contact between the tool and chuck bushings either through lack of lubrication or excessive leverage see Figure 2 4ColdCor r osion Low temperature causes a Demolition T ool to be more susceptible to fatigue failureT ools should be kept sheltered from the weather when not in use A rusty Demolition T ool is more likely to suf fer fatigue failure so tools should be kept well greased 5W orn Internal Hammer P ar ts W orn hammer parts can cause the tool to be held too loosely This can create surfacedamage on the tool which can lead to fatigue failure of the tool W orn parts can also cause uneven striking on the tool which may lead to fatigue failure of the tool and damage to the piston continued on next page