Inconsistent Braking

Chris Munro · August 23, 2009

When braking at higher speeds about 60-80 mph, when I apply the brakes, they seem fine, the brake pedal pushes down fine too, but if I quickly release then brake a bit harder again, the brakes feel alot better, firmer and more responsive. Im not worried about the brakes because the work perfectly fine but it would be good to get them like the second 'push' all the time.

Does anyone have any ideas of why this is? Im not braking long enough for the bakes to get that hot which I first thought it might be. My brake fluid levels are good too.

How easy is it to replace the brakes lines and change out brake fluid?

Any help would be great.

arty-is200sport · August 23, 2009

bleeding the brakes mite just do the trick, mine are the same mate but Ive just been to lazy do do them.

bigdave-is200 · August 23, 2009

BRAIDED BRAKE LINES may help mate.

E910 · August 24, 2009

Sounds pretty normal to me.

Brake pads will outgas and under use may create boundary layer of gas between the pad and the disc hurting braking performance. When you initially press the brake pedal you have to squeeze this gas out before the pad can make contact with the disc. Cross-drilling was created to provide the gas someplace to escape. Although modern brake pads seldom suffer from outgassing problems, water residue may build up after a vehicle passes through a puddle and impede braking performance.

There may also be other factors like pads working better with a bit of heat in them etc.

Although with something as important as brakes if in doubt get it check out my a mechanic. It maybe something as simple as your fluid needs changing. According to the service schedule it should be done ever 20,000 miles or 2 years.

kev dood · September 22, 2009

Sounds perfectly normal. Mine do the same, as will most cars. When you brake, release then brake again, you have built up more pressure in the system which then leads to a firmer pedal.

Dont worry about it, its fine.

fil4362 · October 13, 2009

The servo on the is200 is a double diaphram type its perfectly normal to do as you decride. When doing an mot test theres certain information that the tester is given on his printout check sheet (vt20) the thing you mention (on a printout for is200) is described on this and is descrided as normal even by ministry of transport.

if the car had drum brakes (which they dont ) this would be down to poor adjustment but on an is 200 its normal.