Bosch Power Tools CET3-10, CET4-20W manual Trouble shooting, Problem Symptoms Resolution

Trouble shooting

This section provides a list of the more frequently encountered malfunctions, their causes and corrective actions. The operator or maintenance personnel can perform some corrective actions, and others may require the assistance of a qualified Bosch technician or your dealer.

PROBLEM	SYMPTOMS		RESOLUTION
Excessive air tank	•	Pressure switch does not	•	Set the On/Off switch to Off, if the unit
pressure – safety		shut of motor when com-		does not shut off contact a Bosch fac-
valve pops off		pressor reaches cut-out		tory service center or a Bosch authorized
		pressure		service center
	•	Pressure switch cut-out	•	Contact a Bosch factory service center or
		too high		a Bosch authorized service center
Air leaks	•	Tube fittings are not tight	•	Tighten fittings where air can be heard
		enough		escaping. Check fittings with soapy water
				solution. Do not overtighten.
Air leaks in air tank or	•	Defective air tank	•	Air tank must be replaced. Do not repair
at air tank welds				the leak
			• Warning: Risk of bursting. Do not drill
				into, weld or otherwise modify air tank or
				it will weaken. The air tank can rupture or
				explode.
Air leaks between	•	Leaking seals	•	Contact a Bosch factory service center or
head and valve plate				a Bosch authorized service center
Air leaks from safety	•	Defective safety valve	•	Operate safety valve manually by pull-
valve				ing on ring. If valve still leaks, it must be
				replaced.
Knocking noise	•	Defective safety valve	•	Operate safety valve manually by pull-
				ing on ring. If valve still leaks, it must be
	•	Pump oil is low		replaced.
			•	Add no-detergent oil to pump.
	•	Carbon build-up in pump	•	Contact a Bosch factory service center or
				a Bosch authorized service center
Pressure reading on	•	Regulator is not adjusted	•	It is normal for some pressure drop to
the regulated pressure		correctly for accessory		occur when an accessory is used, adjust
gauge drops when an		being used		the regulator.
accessory is used			•	Note: Adjust the regulated pressure
				under flow conditions while accessory is
				being used.

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