Afternoon all
Had the 500 in for service and MOT a couple of weeks ago. When I collected it and drove home, I noticed the brake pedal felt spongy. I was almost home so rather than turn around I decided I would call the garage when I got back. The more I used the brake pedal the more convinced I became that rather than just being spongy like there was air in the system, it was actually applying too much servo assistance; the brakes were much more sensitive, requiring less pressure to apply than before. It was possible to push the pedal to the floor which was why it felt initially like air in the system, but the brakes were unusually sharp and could be applied with very little effort or pedal travel. It's my wife's car so I don't drive it all that often for it to be immediately obvious, however she tried the brake pedal and agreed it was a lot more sensitive.
The service was a simple oil/filter and air filter change, no brake work, so I decided to lift the air filter and check for any vacuum pipes to the servo which were kinked, loose etc.. Everything looked fine, so I poked around the servo itself and disconnected (what I presume to be) the pressure sensor to see if it was a loose connection. Didn't appear so, so I put everything back together. Went for a little drive and the brakes were back to normal, pedal became firm way before the end of travel and brakes were more progressive as they should be. I assumed the garage had not put something back on properly and all was well, brakes fine ever since...
...until today, as Mrs Carumba messaged me from work to say "the brakes are snatchy again". I'll be looking at the car again when she gets home, and if I can't figure it out tonight I'll drop it back at the garage in the morning for them to have a look. Google suggests sensitive brakes could be an overfilled fluid reservoir, but I would have thought this would perhaps move the brake biting point and change the pedal travel rather than increase the boost.
Has anyone else had anything like this before? I'd like to check as much as possible myself, so at least I can give the garage all the information if I can't find the problem. I have MES and cabling and I'll be looking at the brake pressure sensor output and anything else I can find...
Had the 500 in for service and MOT a couple of weeks ago. When I collected it and drove home, I noticed the brake pedal felt spongy. I was almost home so rather than turn around I decided I would call the garage when I got back. The more I used the brake pedal the more convinced I became that rather than just being spongy like there was air in the system, it was actually applying too much servo assistance; the brakes were much more sensitive, requiring less pressure to apply than before. It was possible to push the pedal to the floor which was why it felt initially like air in the system, but the brakes were unusually sharp and could be applied with very little effort or pedal travel. It's my wife's car so I don't drive it all that often for it to be immediately obvious, however she tried the brake pedal and agreed it was a lot more sensitive.
The service was a simple oil/filter and air filter change, no brake work, so I decided to lift the air filter and check for any vacuum pipes to the servo which were kinked, loose etc.. Everything looked fine, so I poked around the servo itself and disconnected (what I presume to be) the pressure sensor to see if it was a loose connection. Didn't appear so, so I put everything back together. Went for a little drive and the brakes were back to normal, pedal became firm way before the end of travel and brakes were more progressive as they should be. I assumed the garage had not put something back on properly and all was well, brakes fine ever since...
...until today, as Mrs Carumba messaged me from work to say "the brakes are snatchy again". I'll be looking at the car again when she gets home, and if I can't figure it out tonight I'll drop it back at the garage in the morning for them to have a look. Google suggests sensitive brakes could be an overfilled fluid reservoir, but I would have thought this would perhaps move the brake biting point and change the pedal travel rather than increase the boost.
Has anyone else had anything like this before? I'd like to check as much as possible myself, so at least I can give the garage all the information if I can't find the problem. I have MES and cabling and I'll be looking at the brake pressure sensor output and anything else I can find...