Whats it for? sounds expensive
Had one fail after 17 years, just after I've been doing warp factor 9 on the way home . . . slowed down into 30 limit, several miles later, into town, slowed for traffic queuing and whoa . . . pedal sinking to floor . . . an interesting rest of journey as the handbrake wasn't exactly in rude health . . .It's something that rarely fails,
Unusual for them to completely fail as there's two separate circuits. Or was it an old single circuit car ?Had one fail after 17 years, just after I've been doing warp factor 9 on the way home . . . slowed down into 30 limit, several miles later, into town, slowed for traffic queuing and whoa . . . pedal sinking to floor . . . an interesting rest of journey as the handbrake wasn't exactly in rude health . . .
So new master cylinder from a respected specialist . . . 17 mths later, pedal to floor as I pull up at the dentist . . . that was long trip home on a solid bar behind an AA van . . .
Another new master cylinder from a different, well respected, very expensive specialist . . . and touch wood . . . a good number of years later, it's still working . . . But my handbrake has been in perfect working order ever since that first one!
Has the car spent a lot of time unused ? This does not help, and even more so if the fluid has not been changed every few years.
I have never had one fail, even on moon mileage vehicles.
What are the symptoms?
Very strange. Pedal sinking is very common but it doesn't affect the braking.You drive and you brake. Feels OK but then the pedal goes again. It'll stop in an emergency i.e foot to the floor but slow braking is the issue.
So with the engine off, and putting hard pressure on the pedal, it will sink down to the floor ?
You say "then pedal goes again". Do you mean not every time ?
Ever changed your brake fluid?
It's hydroscopic and absorbs water which condenses in the master cylinder reservoir, that's what causes the pitting in components and all sorts of other problems.
Some makes of car need doing very regularly, look in your hand book, you'd be surprised how often.
Nope, twin circuit - I can't remember the failure mode now - whether it simply didn't pump up, or in doing so, emptied the reservoir. I deliberately mentioned my warp factor 9 drive as any lack of braking at that point would have been rather noticeable on a journey I used to make regularly.Unusual for them to completely fail as there's two separate circuits. Or was it an old single circuit car ?