Thread: Brake sizes

I doubt anyone has legislated what size brake drums you should use. Even if they have, laws are seldom retrospective.

It might be just a case of the parts getting harder to find so you might be forced to change due to availability.

Try alko for backing plates.

The “rules” are this – reworded for simplicity.

The rated load carrying capacity of all components must be equal to or higher than the rated GTM (weight on wheels) of the trailer. Of course the actual weight on wheels must be equal or less than the rated GTM.

So, when your 9 inch set was sold it would have had a manufacturer specified capacity rating, as long as that is higher than what it is carrying it is legal.

As far as current OZ standard – that’s crap. I’ve just built another trailer, and every time I’ve fine combed the ADRs and several other standards and there is no reference to brake size, it is always manufacturers specs. Ironically it does specify little things like exactly where you need to fit clearance & tail lights and reflectors ect, and hardly any of the pro built campers / trailers are complying – caravans yes.

HOWEVER, they usually will specify a maximum wheel size for the smaller brakes. The component manufacturer I have used lists 9 inch brakes on 45sq axle with a capacity of 1450kg with 14’ wheels / 1200kg with 15 or 16’ wheels. I would not to do it myself on a new build (this is a caravan few yrs old?), the small brakes would be working and hot but it is legal. You need to go up in size for 1450 with 16

Both Alko and Dexter still make and sell 9' sets and parts in Aus - but they won't be commonly stocked by smaller repairers.

Originally Posted by Pedro_The_Swift

I'd actually like to keep the 4wheel brakes if possible.

yeah - I would rather have 4 x 9inch brakes than 2 x 10inch.

As mentioned above – they won’t retrospect changes anyway, if it is already registered, and it is introduced to the standard now, you’re clear.

Thanks Harlie
I do plan on going to 14"s,, I'm thinking the tyres would be easier to replace (than LT 13's in uppercumbuctawest. (or broome or ---)

I would love to brake test both axels, it would relieve a lot of concerns--

will google dexter

not a lot to show for the last 30 mins searching--
neither of those two companies list 9" electric brakes(that I could find--)
this is the link to alko-
AL-KO Website » Brakes

its interesting how the 13/14's can carry more load than the 15/16's.
but thats with a 10" drum--

maybe i just replace individual bits-
linkage arms and magnets,,