[BigRuss]

Today I've been fitting new calipers to improve the brake performance of the front brakes, one of them was sticking slightly.

Hoses clamped off and calipers changed with no problems

Time to bleed the brakes and thought I'd do it properly on the T4, the sequence is as follows:

Select brake to be bled on screen menu after fitting bleed tube to bleed nipple.
Open bleed nipple and depress pedal to expell air until it runs clear ensuring resevoir is topped up.
Next press continue on the T4 menu to bleed the secondary circuit with the ABS pump until clear.
Finally tighten bleed nipple while pedal is depressed.

All was going well until it came to bleed the secondary circuit........... Absolutely full of air

Took a total of 4 bleed sequences on each side to get it free of air and 1/2 litre of fluid.
The pedal is now solid when depressed.

The problem for members is that normal bleeding or pressure bleed kits only bleed the primary circuit, in order to bleed the secondary circuit you will need to use suitable diagnostic equipment capable of using the ABS pump to bleed it properly.

I wonder if this is why some owners suffer from sinking pedal syndrome.

Russ