Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: JasonH on 13 September 2007, 23:46:55

Title: Spongy brakes
Post by: JasonH on 13 September 2007, 23:46:55

Now this isn't technically on an Omega, it's my brothers Daewoo Espero... which is still a GM design and is really a Cavalier underneath.

Anyway we're stumped and need some expert advice / suggestions.

This has crept up on him, but now when he presses the brake it travels to the stop. There's enough braking to stop the car but not in an emergency and not enough to kick in the ABS.

We've pressure bled the system with litres of brake fluid.

We've bled the ABS unit using some handy manufacturer instructions off the internet.

We figured it must be the master cylinder so he spent £100 and we replaced it.

The problem is still there.

He's tried clamping off each wheel caliper/cylinder (drums on the back), doesn't seem to be any one corner.

Help!

Title: Re: Spongy brakes
Post by: The Barge Captain on 14 September 2007, 00:47:19

Hi mate.
Dare i say it, but that only leaves the abs unit  :(
By the way, how is Mrs JasonH and the little one?

Title: Re: Spongy brakes
Post by: jonathanh on 14 September 2007, 07:19:26

...... or flexible hose on its way out.  Depends where you clamped on each pipe whether you would have spotted it.  

Title: Re: Spongy brakes
Post by: JasonH on 14 September 2007, 08:47:47

We've had a good feel of the flexible hoses and can't feel any bulging when you stand on the brakes - or will it be more subtle than that?

ABS unit  :( very bad will be much more than the car is worth.

Title: Re: Spongy brakes
Post by: jonathanh on 14 September 2007, 12:35:20

just had a thought here

try this:  press and hold the brake pedal, wait till it goes to the floor and then keep holding, maybe a few minutes

slacken the bleed screw on one of each pair of wheel (usually they are diagonally opposite on the same brake feed but I do remember the cortina had a front-back split)

If you have a bulging pipe you should get lots of pressure as the pipe returns to its normal shape.  If you have an internal leak in the system then pressure will be lost and little if any fluid will emerge. (given you've changed the master cylinder then I would suspect the ABS unit)

Another thought, I do remember in the dim and distant past some cars had an 'anti dive' valve on them  (again think it was the cortina), if there is another valve kicking around somehwhere it may not be the ABS unit