Spongey Brakes

First, the age old question - WHAT CAR?

It is possible there is nothing wrong at all, many cars with complex brake systems, such as ABS and EBD, can have a lot of pedal travel as a nature of their design.

Try an Alfa 166 3.0 V6, you can push the pedal to the carpet when stationary.

One point: Did you leave the new, sealed brake fluid container to stand for a day or two before gently pouring it in while bleeding the brakes?

I used to sell brake fluid and nine times out of ten, punters would pick up brake fluid and shake the container, this fills the fluid with air bubbles that take ages to escape.

mrcheerful

Thought they were all pretty much the same ;-)

It's a 1999 Toyota MR2 mk2 (previous shape), discs front & rear, ABS (which I believe is on all 4 wheels, not just the front).

I didn't know that.

But no, I didn't shake it before use. It was bought on a Saturday afternoon, and I did the fluid change on the Sunday.

Daft me, because I had no idea how much ("how little" it now turns out) fluid is needed I bought 2 x 1 litre bottles - didn't want to be left stranded with not enough brake fluid!! The whole system only used around half a litre :-/

Couple of points about the bleeding/flushing, I did it with the engine switched off - felt a bit uneasy about jacking the car up with the engine running! And I didn't push the brake pedal to the floor while bleeding the old fluid out - I've heard that the seals on the master cylinder can go if you brake too hard while you're bleeding the brakes.

Sounds sensible to me. If you are certain that you have bled the brakes effectively then there are steps you can take to isolate/eliminate the problem (if there is one)

With all vacuum out of the brakes (engine off , pump the pedal till it feels consistently firmer) press and measure the pedal travel, I usually measure from the edge of the steering wheel to the face of the pedal with a reasonable repeatable foot full of pressure, do this a few times to get an average. then isolate all the brakes using brake pipe clamps, one for each wheel, measure the pedal travel again, the pedal should have very little movement, if there is any then that points to master cylinder faults or very poor bleeding. Assuming a nice firm high pedal then release one brake at a time and remeasure the pedal travel, it should be obvious if one brake allows much more movement to the pedal than others, the fault might be seized caliper or more air in that brake caliper.

Assuming that you find no particular fault with the aforementioned then there is another trick that works. Apply brake pressure using a piece of wood or whatever and leave the car for a few days with the brakes pressurised. This can remove the most stubborn sponginess from brake systems. It is amazing on motorbikes too, just use an aeroelastic round the lever.

mrcheerful

then isolate all the brakes using brake pipe clamps,

If you haven't got brake pipe clamps, I use Mole grips. You might want to put a bit of cloth between the jaws and the pipe to protect it.

Rob Graham

They're not.

Here's the most extreme SAME MAKE example I've come across:

Lada Riva...even show a hint of wanting to press the pedal and your nose will be pressed up against the windscreen.

Lada Samara..I'm braking, I'm braking harder, I'm using both feet, I've remodelled the bulkhead and the car in front is getting very close now...shit are we going to stop?

LOL, no I meant these have a very complicated system, you're not applying the brakes directly at the pedal, but it's only fitted on this model.

I have only seen one car in my life that had front wheel only ABS (1989 XR2).

It's quite possible that this is normal then, ABS does quite commonly give the impression of a softer pedal compared to a non-ABS car. It will also vary according to make *and* model too, depending on the type of system used.