After fitting my new rear brakes I decided to splash out on an Eezibleed kit to finish the job. The job was really fast when compared to the old
fashioned method and I was finished in under 10 minutes.
Initially the pedal felt nice & firm so I went out for a 'bedding in' session. On the way back I noticed that the pedal could be pushed
to the floor with gentle pressure!! 
It feels as if the master cylinders have both failed - a sharp stab on the pedal gives a firm feel but a gentle push goes to the floor.
Have I just blown my m/c seals with the Eezibleed? I used 20 psi as recommended and at that pressure I had a nice steady flow of fluid through the
bleed tube.
It inverted the M/C seals, very similar to what you describe. You can do the same thing by forcing the pads back without undoing the bleed nipple apparently.
I would suggest that you simply didn't get all the air out of the system.
What calipers do you have fitted to the rear?
Most of the rear calipers with an integrated handbrake mechanism are notoriuosly difficult to bleed completely.
I don't think the problem can be air as the pedal doesn't feel spongy and repeated stabs don't make it any firmer. If I push the pedal
really gently you can feel the pressure give way and the pedal goes to the floor without much resistance at all.
btw - The new rear calipers are Powerlites but the handbrake actuator is so simple (basically it just squeezes the pads together with a cable) that I
doubt if it would make any difference at all, as it is not an internal mechanism. The m/c are bog standard brand new Girling jobbies
Pete - I must admit your answer sounds the most likely. Inverted seals argggghhh I only fitted new m/c last month too - they are a bugger to get to in
my car 
[Edited on 15-5-07 by RazMan]
I have to disagree.
The Eazibleed can't produce enough pressure to trouble a master cylinder that's designed to generate around 725-1450psi (50-100bar)
hydraulic pressure.
You may have a slight leak past the recuperation valve in the master cylinder but 'inverted seals' is highly unlikely (sorry Peteff).
Just telling him what happened with our Astra, no problem with your opinion but this actually happened.
Ok then, before I start buying seal repair kits I think I will try going back to the old fashioned way and see if I get any more air out with
SWMBO's foot. 
It is strange how it is appears to affected BOTH master cylinders though.
If you disconnect the brake pipes from the master cylinder and replace them with bleed nipples, bleed out the air, and this cures it then the problem lies beyond the master cylinder. Obviously if you still have the problem then it must be master cylinder related.
Would agree with Phil J, that is the simplest way to confirm - might be worth a bleed first - you are absolutely certain nothing is leaking? I was in the garage trade for 20+ years, used an eazibleed for around half that time, never caused a problem even on old knackered vehicles - 20 psi can't damage anything in your braking system IMHO
Thanks for all the ideas guys.
I will have a go at bleeding the system again first, then if the problem isn't solved I'll do the bleed nipple on the m/c trick (cunning
that 
) and see what happens.
Sounds like a fluid leak to me, go round every joint that could have been disturbed with somebody pumping the pedal on-off-on-off--on dry every
joint first and use a good strong torch/inspection lamp to examine each joint carefully.
It could be a recuperating seal problem but it is odd it happened in both circuits. This type of problem would show up as the fluid level rising in
the resevoir 2 or 3 mm as the pedal is pushed down.
The way to be a 100% sure it is not a mastercylinder problem is to disconnect the pipes to each circuit at the mastercylinder and replace them with
bleed nipples.
If it is a mastercylinder problem it can't be anything do with eazi-bleed -- might however be down on contamination in the fluid.
quote:
Originally posted by Peteff
Just telling him what happened with our Astra, no problem with your opinion but this actually happened.
As to the arrr "handbrake mechanism" --- emporers new clothes.
Have to agree with B.T Astra master cylinders need no excuse to fail, known them to fail when fitting new pads on more than one occasion. Doubt very much if easibleed would cause problems , I use a Sykes pressure bleeder all the time with no problems which works on the same principle.
quote:
Originally posted by britishtrident
As to the arrr "handbrake mechanism" --- emporers new clothes.
Not trying to teach people to suck eggs etc, but have you got the pipe, bleed nipple connected to the correct place on the calippers? Bleed nipple in the top hole pipe in the bottom. I've seen this the wrong way round a number of times causing air locks.
No problem there as the Powerlite have nipples top & bottom - much easier than the std Sierra jobbies which needed to be removed for bleeding.
One thing I didn't know (Rally Design told me this) Always bleed the inner nipples first, then the outer. It apparently prevents air getting
trapped in the caliper.
Just come back from a short run and everything is still hunk dory so it must have been trapped air after all, although I am now a little sceptical
about the Eezibleed ...... but it might be a coincidence that traditional blleding solved the problem
Glad its sorted Raz.
I have had the same problem before but not got as far as driving it. I have ended up having to pump anything up to a litre through to fully clear the
rear lines before, on a rally car with nothing special about the rear brakes.
What normally happens is a lug of air flows back up the rear line(s) while caliper is off, then when you start to bleed, its trapped somewhere in the
middle, so you get air out first, then fluid, and you think its bled, but there is still the lump of air in the line.