Odd Brake Problem (to me anyway!)

[NickDW]

Hi, I am new to Minors (but not new to classics) but have now bought an MOT failure to sort out for my wife to use.

It failed (amongst other things) on sticky front brakes, which proved to be partially seized cylinders. So, I have replaced all 4 front cylinders, including link pipes and hoses, and bled the system out today.

If I pump the pedal a few times and hold it firm it operates all the brakes and stays firm for as long as you hold it - as soon as you release it though after about 10 seconds it has lost all pressure and goes right to the floor. It will then pump up again and does the same over and over.

I've not had this before, any ideas please?

Cheers, Nick.

[MarkyB]

Have you adjusted the shoes?
Otherwise suspicion falls on the master cylinder.

[simmitc]

As above, adjust ALL brakes. If problem remains then new seals in the master cylinder. If there's any sign of corrosion within the m/c, then replace the whole assembly. There is also an adjustable yoke between the pedal and the m/c, but this should not normally require attention.

[NickDW]

Thanks chaps - I haven't adjusted the brakes yet, thought I would bleed it our first, does the adjustment make that much difference then?

[alainmoran]

yes it does ... also, when you are adjusting the rears, be sure to disconnect the handbrake cable first ;)

[mike.perry]

No need to disconnect the handbrake but make sure that it is fully off and the ends of the cables are pulling on and off correctly. Smear a blob or grease where the inner cable comes out of the outer. Do not adjust the handbrake until the rear shoes are adjusted. See other posts on adjusting brakes

[NickDW]

Thanks for all the advice, I will adjust the brakes later and report back.

[bmcecosse]

You do have to loosen off the handbrake adjustment - slacken back the nuts at the lever, then adjsut up the brakes at the shoes un til they are working correctly, and then tighten the nuts at the lever until the lever is acting nicely as you like it.

[NickDW]

It's sorted, I adjusted up each adjuster and now have a nice firm pedal - thanks again for ak the help.