Roger Blassberg 0 Posted July 15, 2010 I'm about to rebuild the rear calipers with new seals and to replace the flexible hoses. Looking in the Bentley manual it advises to pre-bleed the calipers before mounting them onto the carriers - why is this? Surely I can just bleed them normally once they are fitted. I assume that the pressure regulator valve has to be clamped in the open position when the back of the car is off the ground to allow fluid to flow; is that why they advise pre-bleeding? So far as you know, are all the pre-formed steel brake pipes still available from VAG? - one or two of them look a bit ragged so it would be a good idea to do them too whilst the system is open. Thanks RB Quote Share this post Link to post Share on other sites
dirtytorque 0 Posted July 15, 2010 New lines are a good idea,if you don't make sure you use a very good break bleeding spanner so as to not round the unions off,or else you'll end up cutting the lines and replacing them anyway. Never fitted totally dry calipers so I'm not sure about the pre-bleeding.I would of thought you'd be ok bleeding them as per normal with a good pressure bleeder like the ezee bleed kit. Quote Share this post Link to post Share on other sites
davidwort 0 Posted July 15, 2010 ... good pressure bleeder like the ezee bleed kit. yeah, I really like those too, so much better than getting two people to do the job, I never had any problem fitting a new rear caliper, just bled through normally, same when I did my rear beam bushes and fitted new rear lines. Quote Share this post Link to post Share on other sites
Roger Blassberg 0 Posted July 16, 2010 Partly to answer my own question, I went to VAG about the brake pipes; apparently a lot of the pre-formed ones are no longer available as such. The official advice is to have them made up from stock material to suit individual shapes. Thanks for all responses. Best wishes RB Quote Share this post Link to post Share on other sites
mr_lauraj 10 Posted July 16, 2010 If you want to replace the brake lines, either make them up yourself (use Kunifer as opposed to Copper) or take the old pipes down to your local decent motorfactor who should make you some up at a reasonable cost. I've just swapped to mk4 rear calipers on girlfriends Corrado and I didn't prebleed the rear calipers. I bled them, and then left them over night and then rebleed them. This overnight wait allows any air trapped to work its way up to the top. Quote Share this post Link to post Share on other sites