DAF CF65, CF75, CF85 Series . Manual - part 459

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Safety instructions

ENGINE BRAKE, PE ENGINE

CF65/75/85 series

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1. SAFETY INSTRUCTIONS

1.1 SAFETY INSTRUCTIONS

Fuel

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Diesel fuel is an extremely 

flammable liquid, and must not be 

exposed to naked flames or come 

into contact with hot surfaces. The 

diesel fuel fumes remaining in an 

empty fuel tank form an extremely 

explosive mixture.

When fuel system components are being 

removed, some fuel will escape.

To keep this spillage to a minimum, unscrew the 

tank cap to release any overpressure.

Any spilled fuel must be collected, bearing in 

mind the risk of fire.

Exhaust gases
Do not run the engine in an enclosed or 

unventilated area.

Make sure exhaust fumes are properly extracted.

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Exhaust gases contain carbon 

monoxide.

Carbon monoxide is a deadly 

colourless and odourless gas, 

which, when inhaled, deprives the 

body of oxygen, leading to 

asphyxiation. Serious carbon 

monoxide poisoning may result in 

brain damage or death.

Moving parts
Remain at a safe distance from rotating and/or 

moving components.

Various fluids
Various oils and lubricants used on the vehicle 

may constitute a health hazard.

This also applies to engine coolant, windscreen 

washer fluid, refrigerant in air-conditioning 

systems, battery acid and clutch fluid.

So avoid inhaling and direct contact.

Electrical short-circuit
Always disconnect the battery's earth connection 

during repair or maintenance operations for 

which the electric power supply is not required.

ENGINE BRAKE, PE ENGINE

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Safety instructions

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CF65/75/85 series

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General

ENGINE BRAKE, PE ENGINE

CF65/75/85 series

4

7

2. GENERAL

2.1 LOCATION OF EXHAUST BRAKE COMPONENTS

1.

Operating cylinder, exhaust brake

2.

Exhaust brake valve

3.

Supply pressure

4.

Butterfly valve

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ENGINE BRAKE, PE ENGINE

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General

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CF65/75/85 series

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2.2 SYSTEM DESCRIPTION, EXHAUST BRAKE

Switching on the exhaust brake
The exhaust brake consists of an engine brake 

operating switch fitted in the cab floor and an 

operating cylinder (2) connected to the butterfly 

valve in the exhaust pipe.

If the engine brake control switch is operated, a 

signal is passed to the engine management 

system's electronic unit. The engine 

management system's electronic unit interrupts 

the fuel supply to the various cylinders. The unit 

also energises the exhaust brake valve, causing 

compressed air to flow to the operating cylinder 

(2). The cylinder closes the butterfly valve in the 

butterfly valve housing. The exhaust pipe is then 

almost completely closed off.

Controlled discharge of exhaust gases is still 

possible through a calibrated hole in the butterfly 

valve.

The engine now acts as a compressor, creating a 

braking action.

The higher the engine speed, the greater the 

braking action of the exhaust brake.

Switching off the exhaust brake
If the engine brake control switch is released, the 

fuel supply to the various cylinders will be 

re-instated and the butterfly valve will be 

re-opened.

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1.

Butterfly valve operating cylinder

2.

Exhaust brake valve

3.

Supply pressure

4.

Butterfly valve