totaly stuck... please help

ok chaps heres the problem, Ive overhauled the brakes on my series 3 109, and cannot no matter what I do get a good pedel, Ive checked and double checked that everything is fitted correctly, so lets assume thats all ok, I tried and tried to bleed the brakes to no avail, so even fitted a new lucas master cylinder on it today, but still not pedel its close, you can lock up the wheels on the second pump of the brake but not the first, it just sinks almost to the floor, Ive even pressure bleed the system but still the same, now Ive herd something about a brake failure unit can cause major problems is this right Im at a total dead end folks :doh: any help with this one would be great, I just dont know what else to do...

have you adjusted the brake shoes to the drum correctly using the adjusters?

I had the same problem on a Moggie Minor a few years ago. I replaced the whole braking system but it turned out to be a badly adjusted rear brake line into the cylinder. It was nipped up just a tad then it all worked okay. Good luck.

I think so, you'll have to tell me if Ive done this correctly or not, I jacked up the landy and turned the adjuster until the shoe griped the wheel then slackened it off until the wheel turned freely, I did this all round, dont know if thats the right way to do it or not, but I dont think that is the problem..

If it is stiff after the 2nd pump ( ) then it sounds more like there is a loose connection and air is getting in or fluid is escaping.

On the second pump, does it stiffen up then eventually go to the floor? If so it is def a leak.

first depress of the pedel it goes 95% of the way to the floor before the brakes bite, then second pump it holds firm 40% of the way down and does not sink, there is no leaks anywhere, Ive been through the system with a fine tooth comb, im totaly stumped...

Might be worth checking the snail adjusters if you haven't done so again.....your method is ok but better to get a mate to spin the wheels and then brake a few times to make sure the shoes are seated properly.

Another possibility is ballooning flexable hoses if they are old or cheap replacements.

The brake failure unit just splits the system into 2 (front and rear) and I dont think your symptoms fit.

I had similar problems with mine until I swopped master cylinder for a late series3 version which is a straight fit on the mounting but larger bore than what I was originally given so you could check you have right one fitted.

Have u changed the adjusters s well. The rear shoes will go on 2ways the wrong way the pedal is crap. Maybe be worth checking and if u have changed the adjustsrs they go on 2waysbaswell

Yep, sounds like adjusters.
Another way to check is to lock all the adjusters up so the shoes are tight on the drums. then check if the pedal will take on the first pump. if it does, your adjusters were wrong, if not, there's a leak/wrong M/C etc.
also agree you should check rear shoes...been there, got it wrong!

@ blue beasty- I did replace the old brake hoses for britpart flexi ones so that will be worth a look in the morning...

@ Tobi/mathewpink- the two things I didnt replace was the brake drums and adjusters so the adjusters are deffo the correct ones as is the new master cylinder it's the exact same lucas one as the old one I replaced, but at least Ive got some avenues to go down now, cheers fellas, I'll check the rear shoes tomorrow and swap em round see if that makes any difference, fingers crossed Ive put em on wrong, and I'll check the hoses for ballooning, I'm fairly confident theres no leaks tho, thanks again guys for your time...

I jacked up the landy and turned the adjuster until the shoe gripped the wheel then slackened it off until the wheel turned freely,

Click to expand...

You shouldn't slacken until wheels are totally free, just back off the snails slightly, the wheel will turn but you will feel the shoes rubbing....

yes mate thats what I did...

Had a similar thing with mine....

I have replaced everything - defender master and servo, stage 1 rear axle and new cylinders all over. For the love of money could not get it to bleed down.

Basically it turned out to be the 1 man bleeding out that was a heap of ****....

If the brakes are holdine at 40% of travel on second pump and are not sinking it is air in system.

Thing to do is get a second person to pump pedal and as they are nearing end of travel get them to shout and you close off snail whilst they are still moving pedal down.

You must go diagonally starting with passenger rear brake.

Like I said the 1 man kits are **** I used a jam jar with hose taped to side to ensue it was always submerged.


Also I had to put about 1 liter of new fluid through whole system as on first attempt I fill fluid with air bubbles.

Only way is patience and time....

And the wife at the helm.......