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spongy brake pedal - how do I cure it?
smart51 - 22/3/10 at 06:27 PM

My Cappuccino has a spongy brake pedal. There is a fair amount of pedal travel between braking gently and pulling up fast. It will brake quickly but it doesn't feel nice or inspire huge confidence. Previous brake bleed jobs were done with an eezee bleed kit that uses a tyre to pressurise the reservoir, however the cappuccino doesn't have a screw on lid so I can't use it. Instead I've enlisted a reluctant other half to press the pedal whilst I open and close the bleed screw with a spanner. The problem is the pedal feel isn't improving. Other owners say their pedals are quite firm so it isn't a design "feature".

Is there a special technique for doing it properly?


antonio - 22/3/10 at 06:39 PM

hi
assuming you have no leaks and MC is working properly, you should try to undo the caliper and shake it head up and down (if you know what i mean!) when you bleed it.
i've just done mine today this way, and pedal is much more solid
i remember my lotus elise was impossible to bleed properly without un-doing them
hope that helps
antonio


scudderfish - 22/3/10 at 06:39 PM

Does it have rear drums? My brake pedal felt crap because the handbrake adjustment was crap so the rear pads were travelling further than they should.


dhutch - 22/3/10 at 06:42 PM

quote:
Originally posted by scudderfish
Does it have rear drums? My brake pedal felt crap because the handbrake adjustment was crap so the rear pads were travelling further than they should.
Yeah i also get this on the kit.
- Comes and goes (yay) but ultimately the handbrakes fooked.

Infact, actaully, thats new thread im starting....


Daniel


smart51 - 22/3/10 at 06:47 PM

No, it has rear discs. The rear callipers were rebuilt last year with new slides and seals. I didn't renew the pistons though. I'll try the taking them off trick.


Danozeman - 22/3/10 at 06:50 PM

Does the handbrake work on the caliper or is it seperate?

If its in the caliper take them off and wind them back in. Refit and give the pedal a few pump and take it for a drive BEFORE you touch the handbrake. May need a little turn more on the caliepr screw that it wont do on its own.

Failing that, spongey hoses?


speedyxjs - 22/3/10 at 07:59 PM

Do you want to swap MC's with me? Mine is too hard for my liking


britishtrident - 22/3/10 at 08:11 PM

Check all the callipers pads and pistons are free also the handbrake cable isn't too tight.

You can also try to track the problem down to a corner by clamping one brake hose at a time.

One proven method of getting air out of callipers is to take a a brake pad out then pump the piston out as far as is sensible and with the top off the reservoir push the piston back, you can either get the air out through a nipple or just push it back to the reservoir.


smart51 - 22/3/10 at 08:37 PM

I tried tapping the callipers with a hammer to dislodge bubbles and then bleeding them again. Short sharp bursts with the spanner on the bleed screw this time - not letting the pedal move to the floor. The handbrake is loose enough to turn the rear wheels without resistance when off and with almost no resistance on the first "click".

It is quite a bit better. I don't know if I'm being picky now or not. The seven had very firm brakes. There's still maybe a couple of centimetres of pedal movement between gentle braking and hard braking. Perhaps that's all you can expect from a servoed system on a 16 year old car.

[Edited on 22-3-2010 by smart51]