Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: BobF on 07 September 2009, 19:23:33

Title: Spongy Brakes
Post by: BobF on 07 September 2009, 19:23:33

My 2000 2.5v6 elite goes in for MOT tomorrow and I have just found the brakes are not to good (it's been off the road for 5 weeks). They feel very spongy and if you keep pressure on the brake when stationary and engine running the pedal depresses more. There is no brake pad wear warning. As anybody any ideas as I would like to go straight to the problem in the morning

Title: Re: Spongy Brakes
Post by: GastronomicKleptomaniac on 07 September 2009, 20:09:45

Have a good look around the car for leaks - if you can get it safely up in the air with someone inside to pump the brakes, you might find a leak somewhere.

 Have you pumped the brake pedal up with the engine off, and seen if it sinks?

Title: Re: Spongy Brakes
Post by: Jimbob on 07 September 2009, 20:11:49

possibly inverted master cylinder  :'(

Title: Re: Spongy Brakes
Post by: BobF on 07 September 2009, 20:59:20

Just tried the brakes with the engine off and the pedal does not sink.

Title: Re: Spongy Brakes
Post by: deviator on 08 September 2009, 12:19:38

Quote

possibly inverted master cylinder  :'(

Can't this be rectified with an "My Naff Code Reader" or similar? You can run the ABS system (without engine running) and it forces the rubber the other way. Or have I mis-understood what you mean. IE do you mean that when the piston has been forced back its caused the rubber to go the other way?

Title: Re: Spongy Brakes
Post by: Jimbob on 08 September 2009, 12:49:55

Quote

Quote

possibly inverted master cylinder  :'(

Can't this be rectified with an "My Naff Code Reader" or similar? You can run the ABS system (without engine running) and it forces the rubber the other way. Or have I mis-understood what you mean. IE do you mean that when the piston has been forced back its caused the rubber to go the other way?

no really, if pistons pushed in, the fluid can invert the seals, a whack on the end of the cylinder, while releasing the brake pedal can rectify if your lucky.


the activating abs pump while bleeding is to get air out the abs unit.
again, could be the issue here.

Title: Re: Spongy Brakes
Post by: deviator on 08 September 2009, 14:50:35

Quote

Quote

Quote

possibly inverted master cylinder  :'(

Can't this be rectified with an "My Naff Code Reader" or similar? You can run the ABS system (without engine running) and it forces the rubber the other way. Or have I mis-understood what you mean. IE do you mean that when the piston has been forced back its caused the rubber to go the other way?

no really, if pistons pushed in, the fluid can invert the seals, a whack on the end of the cylinder, while releasing the brake pedal can rectify if your lucky.


the activating abs pump while bleeding is to get air out the abs unit.
again, could be the issue here.

Sorry for the slight (although related) hi-jack.

I know some people with this problem on the vectra have managed to get it back running the abs without the engine running. I know it's not everytime. But it's worth a try.

Title: Re: Spongy Brakes
Post by: BobF on 08 September 2009, 14:54:17

How do you run the abs without the engine running?

Title: Re: Spongy Brakes
Post by: deviator on 08 September 2009, 15:01:32

I believe the ABS unit has it's own electric pump and VX use Tech2 to run the pump up without the engine running.

Title: Re: Spongy Brakes
Post by: BobF on 08 September 2009, 16:34:55

I have now checked for leaks and there are none, I have changed the fluid. Given the master cylinder a sharp tap whilst letting the brake off and the problem is still there. The problem is not there when the car is moving, in fact they seem ok. The problem is not there when the brake is operated without the engine running, it is only when stationary with the engine running, any more ideas guys