VW Passat B5.5 - Brakes lack bite after being blead

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Mon 14 May 2012 09:20
VW Passat B5.5 - Brakes lack bite after being blead - cws

Just blead the brakes on my (2003) B5.5 estate and now they lack bite and have more pedal travel. The first push of the pedal is spongy, and on the second it does bite. Before the blead, the brakes were sharp, requiring less push of the pedal before they bit.

I blead them manually ie without a pressure bleeder, kept the resevoir topped-up at all times, using fresh DOT 4, in the following sequence (as stated by ELSA) - passenger rear>driver rear>passenger front>driver front.

The passenger-front caliper had quite a bit of air come out, so took longer to blead than the other 3 calipers, but we did clear all the air.

For the actual bleading of each caliper, first pumped-up the brake pedal several times to build pressure, then with the pressed pedal down, undid the blead nipple to release the fluid, then closed it/released pedal and so on. Each caliper had at around 5 'pumps' of the pedal (other than the passenger-front which took more to clear out the air).

So what have I done wrong? I didn't think the ABS pump needed actuating (via VCDS) as part of a normal bleed, so am at a loss.....

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Mon 14 May 2012 10:15
VW Passat B5.5 - Brakes lack bite after being blead - gordonbennet

''The passenger-front caliper had quite a bit of air come out, so took longer to blead than the other 3 calipers, but we did clear all the air.''

you had sharp brakes before you started so i doubt there was any in the system prior to this, i wonder if you allowed the level in the reservoir to drop just before this point.

You'll have to go round the lot again, if you haven't got a pressure bleed kit, the good old clear pipe on the bleed valve is still the best IMO, then open and shut the valve during each pump and watch for clean clear fuid coming through....or as i do, wear a rubber glove, hold my finger light pressure over the end of the clear bleed pipe and let an assistant pump the pedal smoothly for minimum half a dozen strokes....i close the valve during the final down stroke.

Start at the furthest point and work towards the nearest, unless your manual tells you different.

When topping up between cylinders, fill gently and allow a couple of minutes for any air to float to the top before resuming bleeding.

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Mon 14 May 2012 10:39
VW Passat B5.5 - Brakes lack bite after being blead - cws

Thanks for your help. I'll repeat the whole bleed again. Do you think I'll also have to bleed the ABS pump (with VAG-COM), if (as it may seem) I've let air in to the system?

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Mon 14 May 2012 11:03
VW Passat B5.5 - Brakes lack bite after being blead - gordonbennet

Do you think I'll also have to bleed the ABS pump (with VAG-COM), if (as it may seem) I've let air in to the system?

Beyond my knowledge i'm afraid, sorry.

Hopefully someone with specific know how will reply.

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