rear brake master cylinder spec needed

[lardarse]

Hi
I've got a 08 ultra that's been trike d and its got the later brembo brakes on it ,can anyone tell me what the standard rear cylinder bore diameter is as I'm planning to change this and try and improve the rear brakes.

[msocko3]

Hi
I've got a 08 ultra that's been trike d and its got the later brembo brakes on it ,can anyone tell me what the standard rear cylinder bore diameter is as I'm planning to change this and try and improve the rear brakes.

From what I can tell doing some digging, its about 5/8".

[lardarse]

Thanks for the help. clappingclapping

[FLTR2008TRIKE]

Which trike do you have?

[lardarse]

Hi
It's a uk made trike,if you Google trike design in Wales you will see some of his work .mines a Brooklands ,very good quality kit ,before I got my ultra I looked round and I found this the best .

[FLTR2008TRIKE]

They don't give much info on the setup they make.

[lardarse]

It doesn't go into detail but after looking at other makes and the quality is good, stainless fittings, independently suspension using mono shocks above the diff assembly and anti roll bars etc.
And he does a lot of specialist adaption for them.

[FLTR2008TRIKE]

Since I cant see what your setup looks like, I would tell you that the first thing before swapping out the rear master cylinder would be to re bleed the brakes.

Bleeding them you should do the left side first then the right. The second re-bleed, switch to doing the right side first then left. This may seem overkill but this will ensure there is no air in the brake system. After that you will have to find out what size piston is in the rear brake caliper(s)

Improving the braking pressure sometimes requires more volume of fluid over just installing a master cylinder with a larger bore piston.

Tom

[lardarse]

They are 've callers with Ford cosworth disc s ,std master cylinder.
The brakes are not poor but being a mechanic by trade if things can be improved I want to.
Thanks for the advice will try that then go for altering m/cylinder size.

[FLTR2008TRIKE]

If you have the Ford Escort Cosworth rear brake calipers they are a little over sized for the stock 5/8" bore rear master cylinder fluid volume. Your rear pedal may be "mushy or soft " The ideal size is 38mm or lower bore in the calipers to keep a firm brake pedal using the stock rear brake master cylinder.

The calipers on your trike kit, if they are the Escort rear calipers are 43mm bore calipers may be the cause of your soft pedal. I would contact the shop to find out what size calipers are on your trike to make sure.

[lardarse]

Hi will check caliper piston size but Ford cos discs are machined down to fit golf rear single piston calipers which have park brake mechanism for uk regs.