brakes

[moggyminor16]

hi all can some one help
i have just replace the master cycender as it was leaking but the new seals would not stop it so had to get a new one . Now after belleding lots of times they are still not right , i used about 1 and a half bottles to do it . there is no more air bubbles coming throw nor is there any leaks as the fuild is not going down at all .
now if i push teh pedal down it gose to the floor then if i press again it half way if i keep the pressure on it will not move at all and if i press it again it gets harder.
this is doing my head in big time
when i press the pedal once and its at the the brakes do work
can any one shed any light on this at all
thansk all

[bmcecosse]

Are the brakes adjusted up tight all round ?

[moggyminor16]

yes they are they will need the shoes changing one day as all on the adjust
just been thinking if the flexi hoses are letting in air but no leaks strang one

[bmcecosse]

Does sound like adjustment problem. For the rears you should slacken off the handbrake cables at the lever - then adjust the shoes up tight - alos make sure all the cylinders are moving as they should. When finished - slacken back the adjusters one notch and then adjust the cables up so the handbrake is hard on at 3 clicks.

[moggyminor16]

right once i have the funds for the shoes i will replace them all round then i could be back i have had metal on metal before and never had the brake this bad

[beero]

yes they are they will need the shoes changing one day as all on the adjust
just been thinking if the flexi hoses are letting in air but no leaks strang one

Flexis may give you a soft pedal if they are old and expand when your foot is on the brake. Do you know how old they are? Might be worth renewing them when you have new shoes.
Best improvement I ever made to my MG's brakes was a set of Goodridge stainless steel braided hoses. I guess they do them for Moggies.

[moggyminor16]

they was all replaced 5 years ago when it was put back on the road

[grumpydad]

are you shore you hav thre right size master cylinder
thay came in 2 sizes 5/8 and 3/4
if you have the small one you wont move enoufh fluid to the wheel clinders
on the first stroke
hope that helps

[moggyminor16]

well i asked for the one for my car from dsn he is normaily right with his stuff fits right all pipes fit right so dose the rod also looks the same as the one which came out of there
but thank i did not know there was 2 sizes was the smaller one for a older car ?

[grumpydad]

yes i think so
but on the out side thay look the same
and all the pipe work is the same
so you can fit either
how do i know
had the same problem
on the out side you might find 5/8 or 3/4 cast in
but the casting is not very high
so wire brush it and you should see it

[IslipMinor]

There are 2 sizes for the master cylinder, 7/8" bore for earlier cars with 7" front brakes and 13/16" bore for cars with the later 8" front brakes. At the same time the rear cylinders were reduced from 7/8" bore to 3/4". The front cylinders are the same at 15/16". The changes were made to reduce the pedal pressure in the later cars by about 15% at the expense of slightly more pedal travel, but not at the need for multiple pedal pumps.

I am not sure that the earlier m/c are still available? Fitting the later, smaller m/c with the earlier larger rear cylinders will make the need for brake adjustment slightly more critical, but that should be all.

The symptom you describe suggests that there is still some air in the system. Do you have the master cylinder pushrod adjusted correctly? As already said all the shoes need to be adjusted up, then start the bleeding sequence with the LH, nearside rear first, then RH, offside rear, then LH front and finally RH front last. The principle is to bleed the furthest away from the master cylinder first - probably a bit marginal to decide with the master cylinder down in the chassis leg!

[moggyminor16]

well the rod has been replaced before i got it with what you ask and home madething with a thred shft all the to teh pedal end i have not ajusted this at all as i would of thought it should be the same pleace could any one help on this one as well do i have to get a new rod or will this do as it worked before but teh old cycender just was to pitted to do any thing with this i will be getting new shoes asap and then try again


i did bleed the brake the way that has been stated 3 or 4 times and yes it seems that there is still air in the system i will do again this weekend but this time i will bleed the full master at each station this way i know there ant any air in the system also will be cleaning all brakes if i dont get teh shoes in time i will make them touch the drums then adjust them up so that the wheels dont move then try it again this way i can see if its the shoes if still the same i will replace the flexiz if still the same well wait and see i just ant got teh time any more due to the work (Milatry)

[bmcecosse]

The rod should be fine. Just adjust the brakes up TIGHT on all wheels and then do a bleed. The pedal should be solid when you finish - and then you slacken all the shoes back one click which should give you max pedal movement of ~ 1".

[moggyminor16]

thanks all i will hopful do it this weekend as i now have a car to sell to get all the bit if need to sorry mondao ST but the moggy will and has to live

[ndavidson]

hey all, iv got a few things i need help with!!!!!!!!!! please can some one tell me where im going wrong...my brake pedal hit the floor when i got the car so i bleed them..nothing happened so i bleed them again,4 times infact! so then i replaced all the chamber things on the brakes...still nothing so then i brought a new master cylinder STILL NOTHING! i have been thru 6 bottles of fluid. and the pedal stil hits the floor. it hits the floor the first pump then after that it goes hard then ya wait a while and it hits the floor again, and so on so on...please can some one tell me where im doing wrong!!???? please. thanks nick.

[kennatt]

you need to adjust all of the brakes,they sound as though there is no adjustment the first push moves them out the second or third makes them hit the drums,adjust then till the drum will not turn then slacken them off one click at a time till the drum turns freely

[ndavidson]

thanks i just done it then..so now i have done that should i bleed them all again or should it had come right??

[bmcecosse]

Yes - you need to bleed them - start at the back and then front nearside and finally offside. Leave the handbrake off - and report back.

[moggyminor16]

yerp done mine now well sort of i now have 1/4 of a pedal at start them one second 1/2 so now all to do is ajust teh rod at master then will be fine thanks agian all for the info

[bmcecosse]

You must leave a little bit of free travel at the pedal........
Is there any chance the 'new' master cylinder you were sold is intended for use with disc brakes - and therefore doesn't have the pressure retention valve fitted ?