am i going mad??? wheel cylinders again?

hi everyone, i have just brought a defender 90, it was cheap at 700 quid and i was very happy with it,it pased its m.o.t fine and the tester said it wants a few little bits doing so i thought,awsome, good little solid motor! front brakes were done when i first put her on the road,as they were metal to metal! so after its mot i moved onto the back brakes, to find it needed two hub oil seals, the back brakes had stopped working after m.o.t, how lucky was that! and it needed cylinders too, so i brought britpart as i needed it fixed that day, and ino they are ****e, but i was gonna buy some better ones next pay day! well they leaked after 2 hours so i brought bearmach ones, they leaked too, after a day!!!! what am i doing wrong,every wheel cylinder i fitted to my 88 leaked and now the same with my 90??? im beggining to think im no good with brakes! i fit the new cylinders, flush new fluid throught the whole systen and let it gravity bleed, then bleed on the pedal with some one else,while i open and close the nipple,furthest from the master cylinder first,and then the drivers side! no heavy pumping just normal bleeding!! what is going wrong? can anyone help please, coz i think im going mad!!! thanks, tom

I really don't know, but you've either been seriously unlucky with parts or are somehow damaging the pistons when fitting

Only other thought was whether somehow the pistons are having to travel too far to push the shoes onto the drums allowing the sealing O ring to travel beyond where it should and fluid to escape

i think iv just been soo unlucky with the cylinders iv brought,i brought 4 trw ones,so genuine ones, and all 4 leaked on my series 3! with new shoes and drums! :jaw::jaw: they were 160 quid for the set! so i swaped them for some more pagid ones from euro car parts,and they were fine,so i might see what happens with the new ones i get on tesday,and then if they die,i will get pagid ones again! i put a new drum on one side coz one drum had oil bedded into it, and the other one was fine! the shoes have plenty of life left,so no need to replace, but its soo frustrating its unreal,i nearly cryed when i found out the bearmach ones were leaking,becuase that is the 6th set now! thankyou for replying tho station house!

Think that's why peeps fit a disco axle or convert to disc's as ****part and branded makes are as bad as each other as reguards wheel cylinders when I had my s11a swb tdi I converted it to 11" brakes on the front as I planed to fit a tdi engine to it and 3 out of all 4 lockhead cylinders lasted 6 weeks so I fitted ****part ones and they lasted 2 years before they started to leak but I have hered of peeps having the same problem but the other way round so I just think its pot luck with wheel cylinders.

my rear brakes seam and look ok for now but when I need to replace anything I mite fit a disco axle and be done with them

yea im fed up with wheel cylinders just popping, they are a pain in the arse, i havent got a probolem with drum brakes,if they are set up rite and working as they should, they are great,but when it comes to getting good parts you just cant now, they are all crap! all i want is some brakes that work, thats all i ask! haha. i will see what these trw ones are like this week! i just cant think of anything that would make them pop! clean fluid,no real pressure put on them, and nice clean brake pipes!

Sometimes the generic budget seals can be rather approximately made. I got a piston and seal kit for my TD5 (all discs so a bit different to yours) last year and whilst the pistons were beautiful the seals looked like bits of rubber tube that someone has sliced up with a Stanley knife. So I ordered a genuine seal kit from another supplier. You could see at a glance they were much better made, and actually were the right shape. So it may not be the pistons and cylinders per se, it could be just a matter of finding a decent seal kit.

I'm sure you're doing this anyway, but of course it helps if on assembly everything is well lubricated with clean brake fluid and the seals are well bedded in to the relevant grooves, and nothing's getting rucked up or twisted as it goes together.

Depends if your confident enough I always strip and inspect the wheel cylinders as I've had a few master cyclinders that came with free swarf! they were blue boxes but they were VERY cheap and they were replaced straight away no quibble