This bleedin' brake system....

[Jonathan]

OK having spent 3 nights on the trot taking wheels off and putting about 5 litres of fluid through all sorts of pipes I'll throw this out out to the audience.

Just put my big brakes on (I'm 99.9% sure they are not the problem btw) - drained the system dry to get rid of all the old fluid (done this twice now).

Bled the fronts, this time they bled very easily 1st time - not a problem, pedal rock solid - perfect.

Got onto the rears, bled them as per the manual with the accumulator charged and it starts making a hissing noise, kinda like puffing your cheeks out and blowing, not loud.

So anyways both rears bleed ok.

Followed the rest of the proceedure, luvly jubly.

Now the issue is when I push the pedal you get this hissing noise from the master cylinder and soon after the pump comes on the accumulator - this shouldn't happen, it should stay charged for 2-3 presses. Hold pressure works fine so there is no internal leak.

Convinced it was ok (for the time being) I took it for a drive but noticed the ABS intruding all over the place, I had possibly 70% of what I thought the car should do but then again it was greasy outside (my folks auto span the wheels last night) and I had brand new tyres on which haven't beeded in yet so I gave it the benefit of the doubt - no probs with the pedal feel at all, exactly how it was before.

Got it back today, again, re-bled the fluid. Inspecting some of the stuff it does have very very small traces of air bubbles in it (so small you have to use a torch to really see them) but by no means enough to cause imo any issues - again why would my pedal otherwise be rock hard, you can't even floor it. But no matter how much I put through it, bleed it, I still get this hissing noise from the master cylinder (sounds like the rear).

I'm adding frest fluid all the time (not the stuff coming out of the calipers) - I'm totally stuck with this, has anyone had this noise happen before / solved the issue ?

Be very grateful to know the answer.

[Jonathan]

Feared this would be the case. I have 2 tricks left to try and then it's a new (differnt) master cylinder job as the only thing I can think of is an internal leak.

Thing is I head my old man talking to one of his mechy friends last night about it "Yeah it's Lotus so it has to be complicated" - no it's not its a poxy GM part