Speed 20 SA brake drum removal

in self isolation in my garage I decided that now is the ideal time to service the brakes after many years and miles of use. So I would like to take of the brake drums, which is not as easy as expected. Took off the wheels, took off the 3 countersunk screws and then the corrugated drive plate. I thought, that now the brake drums would come off, but they are reluctant to leave their position (brakes released). I think, the brake drums are sit (to) firmly on the 5 wheel driving plate studs.
Has anyone experienced this before and has a clever idea how to get the brake drums off without damaging anything. A lever between brake back plate and brake drum seems a dangerous idea as it will most likely break the back-plates.
Thank you in advance for your help.

Hi Peter,  I had this problem on my Speed 25, which I think will be similar to your Speed 20, and solved it as follows:  1.  Slacken off both central brake adjusting wingnuts (on the bulkhead below the steering column) a carefully counted number of turns.  I think I did 5.  This will release all tension in the brake cables, leaving the brake shoe return springs free to pull the shoes clear of the drum.  However they may still be seized in place. If so, go all the way round the outside of the drums giving them sharp taps with a hammer. Hopefully this will release the shoes. There may even be an audible click as they release, and it should now be possible to remove the drums. If this doesn't work a more brutal method, which I have never used on my Avis, but which has worked for me on lesser cars (!) is to reassemble everything, start the engine, give it some revs and release the clutch fairy brutally.

Sorry, I started with numbered steps and then forgot the numbers after (1).  Also, once you have finished the job, don't forget to re-tighten the brake adjuster wing nuts.  I usually stick a reminder to the steering wheel !

Thank you for your reply. The brake drums were very tight on the five wheel driving studs. I got the drums off by carefully hammering them off using a hammer and a wooden block. Very carefull and going round the brake drum it took many determined but not to strong blows to get the brake drums off. But it worked without damaging anything.

Assuming your drums are similar to those on my Speed 25, in order to make life easier in the future, once you have got the drums off, each of the three holes in the drum for the countersunk drive plate retaining screws can be tapped 5/16 inch BSF. Next time you need to take a drum off, slacken the adjusters, remove the drive plate, check the drum is rotating freely and screw a 5/16 BSF bolt into each of the holes until they just contact the hub. Then tighten each bolt gradually in turn until the drum pops off. No brutality necessary. Variations on this method can be applied to most cars with the Alvis-made brakes.

Robin, sorry for late answer. Thank you for the idea to tappe a thread in these holes. This appears to be a good solution and I will do that so that in the future brakedrums can be removed without hammering

Patience is required to remove the drums - they become corroded around the hub flange. A little easing-oil and gentle tapping is the only solution at this stage - it will remove eventually.

There is a better solution for next time: With the drums removed, drill each drum in two opposite places between the set-screw holes. Drill 5/16 inch or whatever size you have and tap with the appropriate thread. Then, next time you want to remove the drum simply screw bolts gently into your new threads and they will force the drum off the hub.

Nick Simpson
Technical Advisor.

thank you Nicholas, drilling and taping a thread, I did that, and it is really the best solution to get the brake drums of.