I have a Octavia diesel 2004 1.9. Have been trying to bleed the brakes but cannot get all the air out. have used an Eezibleed but still no success. When engine is off can get a brake, but when engine is started it looses the brake. Any advice would be appreciated. Thanks

Are you sure there is no break in  the servo piping ?

18 hours ago, lilpet said:

I have a Octavia diesel 2004 1.9. Have been trying to bleed the brakes but cannot get all the air out. have used an Eezibleed but still no success. When engine is off can get a brake, but when engine is started it looses the brake. Any advice would be appreciated. Thanks

 

With the engine running is the brake pedal firm then creeps down, if so this is a normal occurence on a diesel, it should be firm under normal driving. If not then double check all bleed nipples are closed and tight, if this proves o.k then check for airleaks around the vacum pump or servo.

On other VAG models you sometimes have to use VCDS to put the ABS unit into bleed mode

The brake pedal during engine is off will be very stiff and hard to push down. This is because the vacuum pump which is not working because the engine is not running. The vacuum helps brake system to brake more easily which is why you can press the pedal more easily when the car is running. 

This is similar occurrence as for steering. While the engine is shut off turning the wheels will be tough, but when the engine is running turning it will be much more easier.

Based on this i think you are assuming that the brake pedal should be at same stiffness, but it should not. If while bleeding the brakes there is no air coming out of the bleeding valve then it should be properly bled taken that you have appropriate amount of brake fluid in reservoir. 

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Thankyou for your advice. Will try it all and hopefully it will work

23 hours ago, nige8021 said:

On other VAG models you sometimes have to use VCDS to put the ABS unit into bleed mode

Only need VCDS if the ABS module has been changed, otherwise you bleed the system in the normal manor.

1 hour ago, Ju1ian1001 said:

Only need VCDS if the ABS module has been changed, otherwise you bleed the system in the normal manor.

 

If you've gotten air in the ABS pump (replacement or carelessness during bleeding) then ideally it should be purged using VCDS.

 

Alternatively, some people bleed the brakes once, take the car out so ABS activates and bleed again to remove air in the ABS pump.

I have had the same problem, bleed the rear brakes in tandem, then the front brakes in tandem and then go round and do them all individually, this seems to get all the air out when i have had issues before.

 

Of course like others have said, the pedal should not be hard when the engine is running but it shouldn't have excessive travel either.

Edited 30 March, 20179 yr by SuperbTWM