Brake Problem

[islander]

I tested out the 0-60 time of the wedge yesterday, (Not sure if it was under 6 seconds or not but it felt like it!!!!) on a decent stretch of road with a 60mph limit which droped down to a 30mph limit. The speed was reduced with prolonged gentle pressure on the brakes.

The problem was that when I came up to the next roundabout the pedal had gone soft. Within a mile or so the pedal had gone hard again and normal braking could be resumed.

Any ideas of what caused this is?

[350zwelgje]

High percentage of water in the brake fluid....
When the fluid has been in there for over six months and you are having this experience - change the fluid.
At least this is the route I would take (and have done).
At a workshop you can have the brake fluid tested to be sure that this is the problem.
An other possibility would be a too low spec fluid.
I prefer DOT 5.1


Rob

[wedg1e]

Does sound like boiled fluid... but you would normally need to use more than 'gradual' braking to bring it on
If the car's been sat for a while you might have a sluggish piston that's keeping the pads against the disc and causing more heat.
Hardly worth the workshop time to have the fluid checked: drain the lot and pump plenty of new stuff through before final bleeding.

[streaky]

wedg1e said:

... Hardly worth the workshop time to have the fluid checked: drain the lot and pump plenty of new stuff through before final bleeding.

My thoughts too ... note that if you don't know what the fluid (type) was beforehand, do not use DOT 5. DOT 4 is a much better choice for road use, with DOT 5.1 for track use. If there is any risk that DOT 5 was used beforehand (doesn't absorb water and doesn't strip paintwork - do not test by pouring over car!) then replacing all the seals is a good idea - Streaky