The poor brakes on the Iveco Daily 4×4 are a well-known problem and much discussed in the relevant social media forums. So far, my attempts to deal with this problem have been:

– installing an electro-retarder;

– upgrading the Goodrich brake hose; and

– removing the rear brake corrector.  

More recently, I noticed that Iveco Daily 4×2 vehicles have a large vacuum tank.  For some reason the Daily 4×4 version does not have this tank.  The vacuum system does have a small vacuum tank for the turbo actuator control. However, the large vacuum tank shown in the workshop manual diagrams for the vacuum system on the 4×4 is not fitted!  I decided to install one to see if it would make any difference to the braking force required.

Parts

In addition to a 10 mm pneumatic push-fit 90 degree connector, and a two-into-one connector from Amazon (£5), I ordered the vacuum tank and its associated piping for a Daily 4×2. The Iveco part numbers I used are:

• 99480041 AIR BOTTLE £22
• 504222151 Hose £58!

Installation

It is quite hard to find a space to install it, which is possibly why they didn’t bother to install it in the factory.  I found that I could mount it on top of the chassis-rail next to the clutch cover.  I have attached it using a home-made bracket that attaches to the upper shock-absorber mounting bolt.  I had to add a 10 mm spacer between the tank bracket and the side of the chassis to ensure there was enough clearance between the vacuum tank and the fuel lines running up the side of the clutch cover. 

I used a 90 degree and a ‘2 into 1’ pneumatic 10 mm push fittings to join the vacuum tank into the existing vacuum pipework.

Results

Without the large vacuum tank and after the engine is turned off, it takes 3 presses of the brake pedal to deplete all the vacuum in the brake servo.  With the large vacuum tank installed it now takes over 10 brake pedal presses to deplete the vacuum in the brake servo!

Whilst driving on tarmac surfaces I have noticed a possible very slight increase in servo boost, but it’s very hard to quantify without instrumentation to analyse this accurately.  However, whilst cadence braking (e.g. driving on loose surface) there is a big improvement. This is as I would expect with such a large supply of vacuum pressure in the new tank.

To summarise, I don’t know that I would highly recommend this modification unless you spend a lot of time on loose surfaces.

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