Master cylinder

Post by **flatbum** » Tue Mar 27, 2007 11:43 pm

I have renewed all brake pipes and every wheel cylinder on my minor.Had trouble bleeding system.Found that the master cylinder is leaking.Is this a big job and will I have to renew the master cylinder or will I be able to renew the seals ?

Post by **bmcecosse** » Wed Mar 28, 2007 6:10 am

Seals can be fitted - but sometimes the bore has rusted or has scored - and so the new seals don't last. It's a bit of a job to get at the master cyl because the torsion bar gets in the way of the bolts - unless they have already been turned round by someone in the past!

Post by **rayofleamington** » Thu Mar 29, 2007 8:21 am

unless they have already been turned round by someone in the past!

if so - check for grooves in the torsion bar where it has rubbed on the bolts. The head was made very thin to clear the bar, and when the bolts are fitted the wrong way round there is a high chance that the torsion bar rubs on the bolts when under load. I've seen loads of Minors where this has happened.

Have a look in this thread from useful tips - it covers nearly everything you might need to know:
http://www.morrisminoroc.co.uk/index.ph ... pic&t=8563

Post by **flatbum** » Sat Mar 31, 2007 8:57 pm

I have had another look, and the leak may have been just overspill from bleeding.I have bled the system twice, (the second time I saw no sign of any air at all) and I still have to pump the brakes to make the pedal hard.Could there still be a problem with the master which could cause this.

Post by **rayofleamington** » Sat Mar 31, 2007 11:08 pm

Could there still be a problem with the master which could cause this.

yes it 'could' be the m/c, but far more likely it will be air trapped somewhere.

Post by **bmcecosse** » Sun Apr 01, 2007 1:18 pm

Or just the brakes needing adjusted up properly. At the rear - be sure to slacken off the handbrake cables first - then adjust up the brakes as normal - then set the cables to where you want the nadle to be. You should never normally need to adjust the cables - this is just to sort out any bad practice from the past.

Post by **flatbum** » Wed Apr 18, 2007 11:21 pm

Blead brakes again today,adjusted all cylinders and hey presto, I now have a solid pedal.I am still going to renew all shoes cos when I adjust the adjusters right up, I can still move the hubs on each wheel.

Post by **bmcecosse** » Thu Apr 19, 2007 7:34 am

Success!

Post by **Willie** » Thu Apr 19, 2007 8:59 am

I do not know which model you have but, if it is an earlier model which has been uprated to the later 8" front drums you should check which sort of brake adjusters are fitted. If the earlier adjusters fitted then you will find that there are at least five clicks from zero before the shoes reach the drums even with new shoes. The other result is that you run out of adjustment even though the shoes are nowhere near worn out.
The 8" drum adjusters are 10mm diameter across the adjusting screwdriver slot, the ealier type are only 7.5mm

Post by **rayofleamington** » Sat Apr 21, 2007 12:00 pm

when I adjust the adjusters right up, I can still move the hubs on each wheel.

another common problem is that the adjuster snail cam can foul on the shoes, therefore the adjuster will only go half way! If your adjuster doesn't turn 360° then this is likely to be the problem.
You can fix it by filing some clearance on the brake shoe where it is fouling.