Morris Minor Owners Club

hi again'

today i failed my MOT because the brakes wont lock up properly, i have disks on the front and standard drums on the back.... the front disks wont lock up fully... and there a bit hit and miss when they do...

is there any quick way to get that little bit extra braking power??... they were a little rusty so after a wire brush and a hose down they gained a bit more braking capacity(not enough)... one thought i had was to rough them up a little with some course ish sand paper (not to coarse of course), probly wont help at all since all good condition brake disks seem to be shinny....

i dont plan on adding a booster at this stage....as they wont realy help with this issue i dont think....

can any body please explain the role of the top hat in the M/c has on disk brakes and why it is recomended to be removed??? also other than the term the "tophat bit in the M/C" that every body uses... what is the actual name for it, preferaly in accordance to the BMC workshop manual..

thanks in advance

If the disc rotors were that rusty there may well be something wrong with the callipers.
When were the brakes bled last
Agree that power booster wont change that as it only assists with the amount of pressure that you apply to the pedal
I have got 8" brakes on the front of mine and I could lock up anytime I wanted. I dont know why you need discs for normal road use.

Indeed - the discs are just a menace -as I see it - but many others will disagre!
So - you need to take the pads out, just one wheel at a time - and probably buy some new ones, then 'exercise' the calipers by gently pushing the pistons out a few mm with the pedal - and easing them back in using a tyre lever or similar. Do this a few times with each piston and hopefully they will slide rather easier. Clean up the discs as best you can - take them off and get them on the bench if necessary - use a file/emery paper whatever comes to hand! Refit - with new pads (or file up the faces of the old pads if they have plenty of meat on them) - and they should work better! The top hat seal retains pressure in the drum brake system - to keep the shoes near to the drum face - sort of 'auto-adjust' system. It must be removed if using disc brakes - or they will drag and 'glaze' on the discs. Not something I fancy doing - taking a seal out of a master cylinder - but I believe new masters can be bought with the seal already removed. If your car alreday has the dsisc brakes - I assume the seal will have been removed already?