Spongey brakes?

[ianmorley1984]

I have had a quick search through to find somebody with the same problem as me but I can't find one so here goes...


Just fitted 256mm brakes to my corsa b

Surface rust on the discs, brand new pads = need wearing in a little before I get decent braking, I know all this BUT...

Even though I have bled both the brake calipers twice, I still have very spongey brakes, and I need to pump them about 3 pumps to build up any pressure.

I read yesterday on a thread on here (I can't find it today though :( ) that the brake servo of a small engined Nova isn't necessarily capable of powering larger brake calipers because the piston inside the calipers needs more brake fluid in order to move it... Am I on the right tracks with this?

I also read that one way of curing this could be to adjust the brake pedal so it doesn't travel as far?!?! if this is right, how on earth do I do that?!


I am supposed to be having my MOT in the morning but it's looking less and less likely that it is going to happen at this rate :cry:

Cheers in advance for any help guys

[brainsnova]

you need to blead the brake diagonal eg. back left then right front.

[AlexW]

As said do the rears. And its not the Servo but the Brake master cylinder, although it sounds like yours is due to air in the system, and by what your saying it could be just because your sat not moving. Take it for a quick test, be ready to use the handbrake (dont yank it up)

[ianmorley1984]

been for a couple of tests guys already.

I didn't realise that I needed to bleed all 4 corners when I was only uprating the front brakes... school boy error obviously!

I assume that once I bleed the rear two (and the front two AGAIN) I will have the stopping power of superman then?

I fit these to a different corsa B 4 years ago and they were fine straight away, hence why I am confused at this issue!

[brainsnova]

it depends how much fluid you lost while changing them and sometimes the rear cylinders on the back leak.

[ianmorley1984]

I collected the car 3-4 months ago and was towed with a rope. The brakes worked brilliantly then and the car hadn't moved for near-on 6 months! I might aswell have just left them on instead of ****ing about like this! Ahh well, I'll live and learn!

Cheers again guys, Morley.

[craig green]

When I first put 16v calipers on my GSi, the brakes were spongey for a day or 2 then were fine (odd).

It may well be the bleeding method isnt successfull, perhaps ask a garage if they have a compressed air bleeder, it sucks fluid through the caliper nipples & you just keep the reservoir topped up.

Also check you have the caliper pad retaining springs installed correctly. I had mine on wrong on my V6's & the brakes just wouldnt bite, Lee & RJ came over & noticed this & like magic the brakes were excellent simply due to the springs on wrong, but you could barely tell from looking at them.... Get someone to pump the pedal whilst you observe the caliper behind the wheel. Do the calipers move about in relation to the disc? (thats what I had happening)

[edit] btw the servo & MC are fine for 16v calipers.

[Welsh Dan]

What condition are the rubber flexi lines in?

[Stuart]

Gunsons pressure bleeder from halfords/screwfix is top for this work (only about £16)

The servo will have little to nothing to do with the problems.

[ianmorley1984]

cheers guys.

I will check the retaining spring tomorrow, but I do really think that the issue is air in the lines... unfortunately I just started a new thread called "butchered bleed nipples", and the title pretty much explains itself :-(

I really hope the retaining spring is the problem though as it will help me out no end!!


Is the gunsons pressure bleeder the kit that I hook upto my tyre and all I need to do is loosen the bleen nipple then wait for the bubbles to go, as I already have that and I have done both front brakes TWICE and I am getting a little stressed with it all :-(


It is a weight off my mind about the servo and MC being capable as I am all out of cash with it being xmas and all!

[jimbob-mcgrew]

yeh bleed up the rears too.
no offense, but are you doing it right ? as in you, aswel as your helper.
makes alot of difference i find how the brakes are bled to ensure theres zero air in the system.
you havent done them by yourself have you, as in pump the pedal alot then leg it round and do the nipple up, lol ive done this a fair bit myself actually, but as the pedals gone down on its last pump, ive jammed a 2x2 bit o wood on the pedal to the drivers seat, not ideal as it cant hold the force aswel as a human foot, but its the best way ive found doing it myself.

if your bleed nipples are proper munched, id strongly reccomend getting hold of replacements as brakes are too important to overlook, once youve got new'uns, you can go brutalist and get a pair of stilsons on the munched ones, to savage them out and dash em away. if you havent allready got one id reccomend getting a proper brake nipple spanner, there similar to a ring spanner, but with a cutout at its top end to allow u to work around the bleed lines, its so easy to munch bleed nipples with regular spanners and alike if your not carefull.

[Stuart]

thats why the pressure bleeder is vital/handy :D

[ianmorley1984]

no i use a pressure bleeder and do it myself that way. It must just be air in the rear brake lines as I have replaced brake calipers numerous times on vauxhalls and I have never had this problem before

[jimbob-mcgrew]

ah kk, u didnt have that many posts so i assumed u wernt in the know, my bad.
just read your other thread, reccomend pulling the old nipples out with some hardcore mole grips or a pair of stilsons, if its not do-able, like they say, a wheel cylinder is next best bet. wouldnt bother with discs, alot of time/money/hassle.

[ianmorley1984]

cheers for the advice, I didn't take it the wrong way first time mate, I understand that a lot of people with very few posts are often not in the know!

I know they cost a bit more, but rear discs make me feel a bit more manly. Afterall it is a Corsa B that I have done all this work to, and I am not a hairdresser so I need to show off big brake discs to save the confusion! lol