Running gear -> The brake system for Your Volkswagen Multivan SUV Fifth Generation (2003-2015)

Running gear  
The brake system  
ESP system  
From model year 2010 onwards, all T5 vehicles will receive the latest generation of ESP (electronic stabilisation  
programme). This is a further contribution towards the continuous process of meeting the safety targets set by  
Volkswagen Commercial Vehicles.  
The ESP system is not available at present in back-to-back cabs (T5 cabs) intended for subsequent completion,  
e.g. as a mobile home, vehicle transporter or for manufacturing special vehicles.  
Brake booster  
ESP control unit  
(control unit for ABS J104)  
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The ESP system MK 25 A-XT from Continental Teves is installed.  
Hydraulic unit  
ESP (electronic stability programme) also combines  
the familiar functions:  
ABS (Anti-lock Brake System)  
EDS (electronic differential lock)  
TCS (Traction Control System)  
MSR (engine drag torque control)  
Hill hold assist  
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Control unit  
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The system has the following new functions in addition  
to those already named:  
Function  
Functional description  
ARP minimises the risk of rolling over when cornering. If the transverse acceleration  
threshold value set for the individual vehicle is exceeded during cornering, the engine  
torque is reduced and the front wheel on the outside of the curve is braked. This reduces  
the rollover torque. Due to the large payload of the T5 2010, the vehicle load is generally  
included in the ARP control calculations.  
ARP  
(active rollover protection)  
The control unit uses the longitudinal acceleration sender to register the current  
acceleration and uses the ratio between this and the engine torque, including the overall  
ratio, to calculate 3 different load conditions (unladen, half-laden and fully laden). Then,  
according to the load condition, the ESP control unit controls the optimum application  
point for ESP.  
Increased braking power (especially when vehicles are laden) during ABS control. When  
the front axle starts ABS-controlled braking, the brake pressure at the rear axle is  
increased until this also enters ABS-controlled braking.  
Maximum brake support  
Ready alert brake (prefill)  
If the foot is withdrawn rapidly from the accelerator pedal then it can be expected that  
emergency braking will follow.  
Therefore, in such situations, the brake pads are moved up into contact with the brake  
disc so that brake intervention can be more rapid, thereby reducing the braking distance.  
If fading is detected (reduction in brake effectiveness when brakes are hot) then  
the brake pressure is increased using the ABS pump, thereby improving the braking  
effect.  
Fading brake support  
The pneumatic brake assistant is replaced by a hydraulic brake assistant in the T5 2010.  
The brake assistant is activated when the driver presses the brake pedal quickly, but not  
powerfully enough. The system interprets this as panic braking, so the brake pressure is  
increased by the ABS pump until ABS control starts.  
Hydraulic brake assistant  
As soon as the windscreen wipers are switched on, the brake pads are brought into  
contact briefly with the brake disc at regularly intervals, thereby removing any film of  
water from the brake discs that may be present due to rain/splash water. This improves  
the responsiveness of the brake system in wet weather.  
Rain brake support  
Trailer stabilisation  
When driving with a trailer, trailer stability assist keeps the vehicle and the  
trailer on track. According to the requirements, individual wheels of the towing vehicle  
are braked or deceleration is initiated by reducing the engine torque. This means the  
vehicle/trailer combination is stabilised in case there is a risk of it becoming unstable.  
At present, this function is only possible if the trailer tow hitch is ordered as initial  
equipment.  
The ESP control unit incorporates an indirectly measuring tyre pressure monitor for  
detecting a loss in tyre inflation pressure by evaluating the rolling circumferences of the  
wheels. If a tyre loses pressure, this is detected within a few minutes of driving by means  
of specific evaluation of the wheel speeds.  
Tyre pressure monitor TPM  
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Running gear  
Front brake  
16-inch front brake  
On its front axle, the T5 2010 has a 16-inch brake  
system.  
The ventilated brake discs have the  
dimension Ø 308 x 29.5 mm.  
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All T5 2010 vehicles with 132 kW engine or a gross  
vehicle weight rating of more than 3000 kg are  
equipped with new, revised 17-inch brakes on the  
front axle as standard.  
The 17-inch brake is optional for all other engines.  
17-inch dual piston front brake  
The larger brake disc combined with the increase  
in pad contact area, improved pad pressure by a  
double piston calliper and more rigid housing thanks  
to the frame calliper principle mean that the braking  
effect is significantly improved, thereby increasing the  
performance of vehicle models with a 132 kW engine.  
The ventilated brake discs have the  
dimension Ø 340 x 32.5 mm.  
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16-inch rear brake  
Rear brake  
The rear axle of the T5 2010 is fitted with 16-inch  
brakes.  
The ventilated brake discs have the  
dimension Ø 294 x 22 mm.  
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Brake light switch on main brake  
cylinder  
Brake booster  
Tandem  
The mechanical switches on the pedal mechanism  
have been discontinued in all T5 2010 vehicles, and  
replaced by a brake light switch on the tandem main  
brake cylinder of the brake booster.  
main brake cylinder  
This brake light switch is one component that  
comprises two Hall sensors (to provide redundant  
backup).  
Brake light switch  
The signals from both Hall sensors are sent to the  
engine control unit.  
The brake light switch can be renewed individually.  
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Clutch position sender  
Exclusively in the 132 kW engine version, a sender  
positioned on the clutch master cylinder is used for  
establishing the clutch position.  
Clutch pedal  
Two Hall sensors installed in the clutch position sender  
register when the clutch is actuated and also when the  
clutch pedal has been fully depressed.  
The clutch position sender cannot be replaced  
individually.  
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Clutch position sender  
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