VW Transporter T4 Brakes Issue

[avidfan]

Very occasionally when I'm stationary with my foot on the brake pedal, it seems like I loose pressure in the brake system and the pedal drops to almost the floor. When I release the pedal and push down again all seems well. This only happens when I'm stationary but I'm worried it may happen when I'm moving!!!! Any ideas guys????

 

[Mursal]

If the brake fluid level is going down, you will have to investigate why? If not, I would suggest the master cylinder at the pedal or if you have ABS, it could be the module.

Edit1: Typo

 

[Peter.N.]

Sorry error

 

[avidfan]

Fitted new master cylinder and all good.. Thank you