Rear drums

[TStanb]

I’m very sorry for all these newbie questions but I am assuming that the A35 rear drums I have in stock will fit my rear MM brakes? Reason for fitting is that they are in far better condition inside
Thanks

[ampwhu]

A35 drum size is 7" on the rear. Also bolt pattern might be different.

[ampwhu]

A35 drum size is 7" on the rear. Also bolt pattern might be different.

[TStanb]

thanks. Bolt pattern is the same and both are 7".
On inspection, one side of the backplate was not fitting totally flat to the axle. I gave the bolts another few ft/lbs and "bingo" ...it was all square and the drums spin nicely...

[TStanb]

Still got problems with the drum not fitting properly onto the hub.
Two questions....
1. can you remove a slave cylinder without removing the half-shafts?
2. the lower (weaker) shoe return spring looks overstretched and is very slack. Would this cause binding problems?
Many thanks

[liammonty]

Assuming that by 'MM' you meant 'Morris Minor' rather than 'Series MM' Morris Minor, which had a completely different rear axle set up, then:

1. Yes, you can remove a slave cylinder without removing the half shaft
2. Yes, a weak return spring could lead to an issue with binding brakes.

Re the binding brakes, there are numerous other potential causes, including the rear flexi hose collapsing internally, sticky wheel cylinders and the master cylinder. Potential causes to look at if your springs turn out not to be the issue.

[philthehill]

Re your reference to the lower spring - there is no lower spring. There are two vertical springs. The front spring has a top and bottom coil. The rear spring has just one coil.
Have you fitted the springs into the right holes in the brake shoes?
A photo of the brake shoe set up as fitted would be helpful.

[TStanb]

Re your reference to the lower spring - there is no lower spring. There are two vertical springs. The front spring has a top and bottom coil. The rear spring has just one coil.
Have you fitted the springs into the right holes in the brake shoes?
A photo of the brake shoe set up as fitted would be helpful.

I can get a photo of the assembled backplate off the car in a minute...please stand by

[TStanb]

This side looks a lot more “correct” and there’s no slop in that “smaller” spring.

[philthehill]

Observations!
The Minor axle is not fitted to a Minor but to either a trials car or special.
Because of the application the brakes are not orientated around the axle as per Minor. i.e. the brake wheel cylinder is not forward of the axle.

Conclusions!
The brake springs are fitted correctly as in photo 34AD159B-------------------.
If the brake shoe return springs are not sufficiently strong enough to pull the brake shoes away from the drum they should be replaced.

[TStanb]

Observations!
The Minor axle is not fitted to a Minor but to either a trials car or special.
Because of the application the brakes are not orientated around the axle as per Minor. i.e. the brake wheel cylinder is not forward of the axle.

Conclusions!
The brake springs are fitted correctly as in photo 34AD159B-------------------.
If the brake shoe return springs are not sufficiently strong enough to pull the brake shoes away from the drum they should be replaced.

Yep, it's a Cannon.
Will buy new "bottom" springs. The big chunky ones at the "top" look very strong. Might as well buy new shoes while I'm at it.
I don't suppose there is any reason why I cannot re-orientate the backplates so they face the MM, either? It might even make the handbrake cables easier to fit?
Thanks

[philthehill]

I suspected it was a trials car. I used to do production car trials in my Minor before she was converted to compete in speed events.
There is no reason that you cannot turn the backplates to make the fitment of the handbrake easier.
Just be aware that there is a drain in the backplate to take way any oil that has passed the hub seal. That drain must be maintained even if it means drilling a new hole in the backplate.

[TStanb]

Thanks Phil.
I have given up circuit racing the Mini Cooper S and intend to go hillclimb/sprinting in the future (it was how I started motorsport in my dad's Ginetta G15).
The Cannon sporting trials car had been lying around for years and it looks like a lot of fun, so I thought I'd do it up and compete in the winter. I have since realized though that restoring and/or rebuilding what essentially is a "special" is a whole lot harder than doing up a MM or a Mini as there is a lot more thinking for oneself involved...an ability that I have always sadly lacked.
As you probably know, the handbrake system is a vital part of the car as the independent Left/Right fiddle brakes are what help get you up the hills...so I've got to get this bit right.
The powerplant is also a 948 A-Series with a later smooth-cased box , hence my recent thirst for MM knowledge
.
Cheers
Tim

[philthehill]

Tim
Many thanks for the above.
To get the brake wheel cylinders to the front you could swop the brakes from side to side. An easy mod and no complications.
Phil

[TStanb]

Tim
Many thanks for the above.
To get the brake wheel cylinders to the front you could swop the brakes from side to side. An easy mod and no complications.
Phil

Thanks but in the pursuit of service-ability at the venue, I'm going to keep them at the back. By-the-way, should the slave cylinders be free to slide backwards and forwards in their slots? The drum binding side's slave cylinder is binding in its slot.
Also, do you have a reliable and permanent suggestion on how I can extend the length of the outer handbrake cables? I am going to have to shorten the inner cables anyway

[TStanb]

Tim
Many thanks for the above.
To get the brake wheel cylinders to the front you could swop the brakes from side to side. An easy mod and no complications.
Phil

Thanks but in the pursuit of service-ability at the venue, I'm going to keep them at the back. By-the-way, should the slave cylinders be free to slide backwards and forwards in their slots? The drum binding side's slave cylinder is binding in its slot.
Also, do you have a reliable and permanent suggestion on how I can extend the length of the outer handbrake cables? I am going to have to shorten the inner cables anyway

[philthehill]

The rear wheel cylinders must be able to slide in the slot of the back plate so as to enable the brake shoes to centralise inside the brake drum.
Any good yacht chandlers with a rigging shop should be able to swage a ferrule onto the brake cable inner wire in the position you desire.

[TStanb]

The rear wheel cylinders must be able to slide in the slot of the back plate so as to enable the brake shoes to centralise inside the brake drum.
Any good yacht chandlers with a rigging shop should be able to swage a ferrule onto the brake cable inner wire in the position you desire.

Thanks very much