Morris Minor Owners Club

Hi,

Just completed fitting a set of second hand Marina discs with new pads,shims etc to the mighty Mog and now they are binding. Following previous advice from this excellent forum, I removed the top hat seal from the master cylinder. It may be just that the calipers have not been used for a while and are a bit 'sticky' but if anyone has any tips that will save me stripping them down and have to bleed the brakes yet again, it would be very much appreciated. Thanks.

Is there still some 'free play' at the master cylinder ?? It has to come right back to release all the pressure in the system. To test - slacken a front bleed nipple immediately after using the foot brake - if there is a 'spurt' of fluid - there is obviously still pressure in the system. If no pressure - the calipers must be needing an overhaul. You may get them free if you simply push each piston back into the caliper a couple of times - and press it back out with the pedal. But a new set of seals and possibly new pistons (get stainless if you can) is the real long term solution.

Thanks very much indeed for the excellent advice; I'll give it a try.

Cheers,

Clipper

I stripped down a couple of these last year. I found the pistons were a little corroded around the internal seal, but not too far towards the back of the piston.
I cleaned them up (with the seal removed!) with 'wet and dry' paper using a little brake fluid as a lubricant, working only in a circular direction around the piston, being careful not to touch any of the good area with the wet and dry.
Just a case of dirt and water squeezing past the external piston seal over time, but this can build up and cause sticking.
I think some additional protection around the external seal would be useful. Personally, a smear some grease around it to help keep water out.
Check the inside of the cylinder for corresponding gunge marks. You have to decide whether or not cleaning it up will adversely affect the effectiveness of the seal.
If you decided to clean everything up and refit, keep an eye on the area around the calipers for a while, until you are certain there are no leaks. Difficult if you are using the car in wet weather........

I would recommend stripping them down and checking everything, and the fitting of new seals as routine. I only trust a braking system when I have seen every single component of it! It's not much effort to do this on a Morris, and you later have a high 'satisfaction factor' every time you press the pedal.
You might be surprised just how awful the condition of a brake system can be, although it still functions.