S40 1.6 2008 Brake oddity ?
 

On driving my S40 2008 a few days ago i had the shock of my brake pedal going down to the floor . It worked okish after 3 pumps each and every time i used it .Garage has fixed it ... my off side rear brake calliper was full of air and there seemed to be no obvious reason for the air getting in . The Main cylinder was ok and there were no leaks and no fluid use . He thought it could be the ABS unit maybe . As of now they are working better than ever .
Any experiences similar to this ? Thanks very much .

does the clutch run off the same resevior on that car? could it be you have a failing clutch slave?

Thanks , i will look into that ...

Hi they do both run from the same reservoir but the feed for the clutch is higher than the brakes, so if your fluid was low, you would potentially lose your clutch first rather than brakes, bit of a safety thing by Volvo.

They bled the whole system down and got the brakes back but still could not find the problem cause . No fluid loss at all . We are going to change the master cylinder as it is the most likely cause but we still don't know . Wondering if i should take it somewhere else for a second opinion ...

Just to finish up on this post ... got a Brake master cylinder from a breakers , garage fitted it and applied good amounts of pressure to the system after which the brake calliper ,that had been filling with air previously , began to leak fluid . So different Master cylinder and new calliper and feels better than ever ... hopefully that's an end to it . Thanks for the comments.