Brakes problem - HELP ! - tell me what to do next

I getting frustrated, very cheesed off, mot is looming.
I have a problem with brakes on my series bitsa
Brakes are LWB drums, 2 pistons on each front drum, 1 on each rear
Twin circuit with long master cylinder
small servo
(I think the master and possibly servo carried on into 90/110)
4 of the 6 wheel cylinders/pistons/slaves are brand new Pagid, the other two werent leaking so have been left alone.
Master cylinder is new

Problem - pedal keeps sinking to floor, after a few pumps it is solid, leave for a second or two and its back to pumping again

What Ive done
Bled and bled and bled, by pumping pedal, by using easibleed - no change
I was convinced there couldnt be any air left in system
Isolated the rear brakes by clamping off the flexi hose (mole grips) - solid-ish pedal straight away. So I bled the rears again, using a bit more pressure - no change.
Perhaps the fault lies in the brand new Girling master cylinder ? Dont have the fittings to make blank pipes for it, given one fitting is oversized. Changed it for a brand-new "Britpart" cylinder that I have (another story). Pressurised to bleed, instantly blew the fluid reservoir apart. 15 psi.
(I'll never knowingly buy ****part anything after seeing how poor the brake parts are)
So
what next ?

anyone know what thread the master cylingder-pipe take-offs are ? I could make a blank up and test it. ?

Anyone near me got a dual-circuit master I could try ?

Any other ideas ?

i had an issue like that recently on my 110 rear drums.

the snail cam had worn in such a way that i thought they were adjusted correctly, but in use it was hit and miss. it seemed to lift the lining up and the post jumped the snail.

i used a bearmach snail kit.. was a bit crappy quality but worked.

Had same probs on my 110.
Pedal slowly sank and needed pumping all the time. The sinking was air getting in the master cylinder.
I replaced the master cylinder as simple job and also replaced the rear brake adjusters as the cams were not adjusting the shoes correctly (hence the need to pump up the pressure)
Sorted mine out and still great braking 18 months on

Are you sure that you have sufficient free play at the master cylinder push rod ? Lack of can course some of your problems. Are the shoes/springs adjusters etc. assembled correctly ?

Thanks for the ideas !
how do I check/adjust master push rod ? Its on a servo.
Adjusters havent been off, could be they are worn out. How do I tell ?
(I've never had to work on drums before, this is all new to me)

landover said:

Thanks for the ideas !
how do I check/adjust master push rod ? Its on a servo.
Adjusters havent been off, could be they are worn out. How do I tell ?
(I've never had to work on drums before, this is all new to me)

Click to expand...

you did adjust the drums though via the snail cams? you need to do this for drums or you'll get the symptoms you described.

depending on drum type, you turn the bolty looking thing (or two) on the back until the drum locks, then back it off until it's free to spin. press the pedal a couple times to settle it whilst adjusting.

else when you first pump the pedal, you'll just be pushing the lining out to the drum, then next time you pump it can move enough to push against the drum and stop

I think Ive found the problem - a brand new Pagid wheel cylinder is leaking
The supplied bleed nipples are a poor fit in all of them
The whole lot might be going back tomorrow
Can people reccommend a good make to buy asap please

Cylinders sorted - problems persist - anyone reckon it could be a brake hose ? I'l change the rear one anyway. Getting good at bleeding now

It does look like it's the rears that are the issue. The single cylinders usually bleed OK (ish) it's worth checking the obvious - is the bleed nipple on the top? You'll need the pistons all the way in, adjust the brakes all the way before bleeding or pop the drums off and push the pistons together with a g cramp. If you've got an air lock in the pipe (I think there's a bit where it goes up and down) try using a pressure bleeding kit. Some of the series owners here swear by bleeding the brakes backwards, forcing the fluid under pressure into the wheel cylinders - search for appropriate threads.

clamp off the rears again and make sure it goes solid.

if so, then it's your rears.

you do know how to adjust drums don't toyu? turning the nut on the back? (just checking)

if it comes to it, take the drums off, gclamp the cylinders well and try the pedal. if nothing leaks then you know something is wrong mechanically inside the drum

i've also shift some air by eezibleed and also pumping the pedal

I's a been a eezi bleedin pedal pumpin up an down my temper thumpin

got the rear flexi hose off today before it got dark
That was a faff, couldnt undo it, broke the hanger - does that come off ? How ?
Anyway, cant find anything wrong with the hose. Looks good, can blow air through. Will put a new one on anyway and continue.
Going back to g-clamp the pistons again and try again, all very frustrating

good luck, shame your not closer

no no, its a shame YOU arent closer !!!

have you checked the springs are correctly fitted on rear and not from shoe to shoe, if they pull the shoe in at piston end it can require two pumps of pedal to get a hard pedal but when you take foot off if spring fitted wrong it pulls the piston to far in requiring 2 pumps again, makes you think its air but not

I hadnt thought of that, will check. Didn't realise its possible to fit the springs wrongly. Still, Ive been bitching about the poor/archaic design features for a week or two now.
Presumably springs should go from shoe to post.

Does you rears have two adjusters being a 109 , if so springs are shoe to shoe.

Thanks - I was wondering how to change that.
It has one adjuster at rear. Ive fitted the bigger bore pistons to match having LWB set-up on front, despite the vehicle being a SWB.

I think its time to buy all new adjusters just in case, nothing left to replace after that.
I gather from posts on here that, as usual, the cheapo ones arent much use; can people suggest where to get decent ones if available