Brake issues 87 classic

Hi, Im struggling to get working brakes on my rangie,

First the front left flexible failed on the primary circuit on the front left corner when someone pulled out on me at 40mph, and I have a very heavy foot which managed to lock up all four wheels but miss the car. So four new flexibles were ordered from my usual mail order parts supplier, and when they arrived promptly, the rangie booked into a local garage to change them as I didnt have time myself.
I collected the rangie, and the mechanic warned me that the brakes were very very bad, as they had been unable to bleed them up properly due to a fault, but as they had only been asked to change the flexibles, they had only superfically looked into it (GRRRRRR, when did" fit these hoses and make the brakes work " become "just fit the hoses and leave me in the crap").
With my faith in the garage shakey, I did a emergency stop near my house to test things out and one of the new flexibles failed immediately (manufacturing defect, they hadnt been pushed fully home into the crimp when made) leaving me with NO BRAKES (not even the crap secondries) apart from the handbrake which is poorly too (and of course on my todo list). I see they tested the brakes properly too then. They must have got just the secondry circuit to operate and decided that at least I had brakes...

So, after explaining the defect to my supplier they sent out a new flexible foc as you'd expect on the proviso I returned the old one for analysis. I fitted the new flexible and couldnt get the brakes to bleed up either. I stripped the master cylinder to fit a new set of seals into it, and found some small damage to the bore, and brakes have to be RIGHT, so a brand new ap master cylinder was bought.
Ive fitted the master cylinder and still it has no brakes to speak of. Symptoms are the brakes seem to come in *just* above where the pedal hits the floor, theres nothing at all before that point. Ive been round the car 3 times and put 4L of brake fluid through the circuits with a ezbleed, methodically working each corner in turn. Theres no more air coming out the system in the fluid so it appears to be bled up, but still nothing on the pedal. Theres no signs anywhere in the system of leaking fluid, ive had all the calipers off, checked the rear flexible etc.

Now, where now??? That balance valve on the inner front wing or the servo?
Im theorising there could be something wrong with the servo internally, but surely a servo would be designed to fail gracefully, ie be a solid connection in->out and only assist this connection, so in the event of faliure, it just means you have to push the solid pedal harder.
Is this a correct assumption? And how can I test the balance valve?

Oh I should add the fuel injection thinks the brakes are working as when you push the pedal to the floor, the rev's pick up slightly. Is it supposed to do this or is this a leakage on the servo?

Its a 1987 classic, I need to add...


Tia
MrFluffy

Aaah Mr Fluffy.
The rvs coming up is correct as if you pump the pedal lots they go quite high, but i have to say it sounds like there's still air in there to me and to be quite blunt, you should not have taken it off the forecourt. The garage has been payed by you to fit new hoses and to be honest any reputable mechanic would make sure that everything was working before you turn up, or phone you to inform you of the problem. If they say there is a fault they bloodywell need to to tell you what it is, not do nothing about it. What happens if you have a crash on the way home, don't use them any more. I think that you might need to spend some more time bleeding the brakes starting on the one furthest away just to make sure. Here's the interesting bit, when i had a new master cylinder fitted to my 109 v8 there were no brakes for about two days, until the seals had swollen ! It was my mechanic who told me this and he said that he would just leave the car alone overnight or a couple of days and it would sort itself. I went to the garage two day's later and everything was fine, i have had no trouble since. Now my mechanic is a friend and has no reason to lie to me but, he may talking rubbish but the brakes did what yours are doing and then they were fine.

Cheers, Nick.

njh said:

Aaah Mr Fluffy.
The rvs coming up is correct as if you pump the pedal lots they go quite high,

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Thats a relief, I was a bit "is it isnt it" over if the ecu knew about brake pressure or it was just the servo leaking when pressed, or maybe the servo leak is HOW it increases the rev's and thats design. As long as yours does it too Im ok with it and wont spend a day ripping the servo out the footwell to poke it with a inspection stick...

njh said:

but i have to say it sounds like there's still air in there to me and to be quite blunt, you should not have taken it off the forecourt. The garage has been payed by you to fit new hoses and to be honest any reputable mechanic would make sure that everything was working before you turn up, or phone you to inform you of the problem. If they say there is a fault they bloodywell need to to tell you what it is, not do nothing about it. What happens if you have a crash on the way home, don't use them any more. I think that you

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Its a rare old thing I put anything into a garage but I was in the situation that I needed it done and didnt have time to do it in the evenings after work. I think driving it home was in the end the safer option, but no Im not happy because I could have sent the wife to collect it and she isnt quite as into vehicles as me, and would have just driven it home expecting it to be right, and not taken the quiet backroads and driven slowly as a result of paranoia. You learn quickly which emporiums you will never go back to, and Ill write this off to experience.

njh said:

might need to spend some more time bleeding the brakes starting on the one furthest away just to make sure. Here's the interesting bit, when i had a new master cylinder fitted to my 109 v8 there were no brakes for about two days, until the seals had swollen ! It was my mechanic who told me this and he said that he would just leave the car alone overnight or a couple of days and it would sort itself. I went to the garage two day's later and everything was fine, i have had no trouble since. Now my mechanic is a friend and has no reason to lie to me but, he may talking rubbish but the brakes did what yours are doing and then they were fine.

Cheers, Nick.

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Ill get another bottle of fluid and work round it again,try and get to it in the evening this time, itll have had time to swell by then...

Cheers Phil P