Aftermarket front master brake cylinder replacement?

[macca__macca]

Hi all,

I've noticed some ageing and external cracking appearing on my front master brake cylinder. The inside appears fine but I am wondering if there is some very, very slight air starting to seep in through the external cracks that are invisible to my eye when looking on the inside of the cylinder, but nevertheless present; it could account of the apparently rapid ageing of my brake fluid?

Replacing the OEM master cylinder is really expensive, and there seem to be loads of cheap aftermarket ones. My question is:
1. Does it matter what size the cylinder is? Many aftermarket cylinders have a much smaller volume capacity.
2. Does it matter that most aftermarket cylinders don't have screw screws that hold the lid/cap one, but rather have a screw-on cap (like a milk bottle)?
3. Anything I'd need to be aware of when replacing the cylinder with a non-OEM part?

Thanks!

[mik_str]

Which calipers are you running? If you're running stock units, an OEM Brembo radial MC from a late-model R6 or R1 would be a nice upgrade for not much money.....

Word of advice: don't let yourself get drawn into the large (piston dia.) MC urban legend (seems to be a common myth where people confuse a stiff lever with powerful brakes)....

[Stephan]

Replacing the OEM master cylinder is really expensive, and there seem to be loads of cheap aftermarket ones. My question is:
1. Does it matter what size the cylinder is? Many aftermarket cylinders have a much smaller volume capacity.
2. Does it matter that most aftermarket cylinders don't have screw screws that hold the lid/cap one, but rather have a screw-on cap (like a milk bottle)?
3. Anything I'd need to be aware of when replacing the cylinder with a non-OEM part?

Thanks!

ad 3. Avoid cheap china. I don't know any of them have worked properly in long term

generally, oem pump is serviceable, repair is worth to consider.

With oem calipers, pump from cbr600f4 is nice upgrade, I believe radials from R6 would be good (better) as well.

What really matters is piston size, don't go over 16mm. Leverage is question, as there are no specs available for oem units. But with 16mm piston size you shouldn't go really wrong.

[sirch345]

The standard OEM Firestorm front brake master cylinder has 14mm piston. AMcQ's thread (link below) should be helpful:-
http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=15494

I can't comment on the Brembo Radial master cylinders personally, as they must have a different lever ratio to the standard Firestorm master cylinder due to the Radial design,

Chris.

[AMCQ46]

The standard OEM Firestorm front brake master cylinder has 14mm piston. AMcQ's thread (link below) should be helpful:-
http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=15494

Chris.

thanks chris, saved me finding and posting, but read through that then ask some more questions if you are still undecided

[sirch345]

thanks chris, saved me finding and posting, but read through that then ask some more questions if you are still undecided

I ought to know where it is Al, I spend enough time looking at your chart A very handy thread that

Chris.

[popkat]

I think your talking about the reservoir pot and not the master cylinder.
£27 for the pot. shown in picture on link.


https://www.fowlersparts.co.uk/parts/51 ... r-cylinder



.

[AMCQ46]

if it is the pot you are after, I think I have one in the shed left over from my conversion. let me look and see tonight

[lloydie]

I think your talking about the reservoir pot and not the master cylinder.
£27 for the pot. shown in picture on link.


https://www.fowlersparts.co.uk/parts/51 ... r-cylinder



.

That's what I thought too but thought I miss read it ?!

[macca__macca]

My apologies all - I am indeed talking about the reservoir pot!

EDIT: Thanks everyone for the input and links. Looks like Storm' parts are significantly cheaper to buy in the UK compared to Australia (though shipping is always a killer).

Cheers!

Macca

[macca__macca]

... and now having clarified I meant to say 'reservoir', can anyone answer my original questions regarding reservoir size/capacity and whether or not this impacts anything? Does it matter how large the reservoir capacity is?

I feel like it shouldn't make a difference - the clutch reservoir is much smaller for example, but then again there must be a reason for it being the size it is...

[lloydie]

The size doesn't matter with the operation of the brakes as long as you keep an eye on it .
For safety reasons I prefer a larger one just in case you get a leak somewhere.

[Stephan]

... and now having clarified I meant to say 'reservoir', can anyone answer my original questions regarding reservoir size/capacity and whether or not this impacts anything? Does it matter how large the reservoir capacity is?

I feel like it shouldn't make a difference - the clutch reservoir is much smaller for example, but then again there must be a reason for it being the size it is...

brake fluid working temperature vary from cold to hot, clutch is stable. So you need space to let fluid expand. Also for safety reasons as lloydie mentioned, it is good to have more fluid, as well as enough empty space.
I would go at least with original size.

[NZSpokes]

Which calipers are you running? If you're running stock units, an OEM Brembo radial MC from a late-model R6 or R1 would be a nice upgrade for not much money.....

Word of advice: don't let yourself get drawn into the large (piston dia.) MC urban legend (seems to be a common myth where people confuse a stiff lever with powerful brakes)....

Funny thing is my stock brakes with fresh fluid, braided lines and HH+ DP pads are stunning. I dont need any more power. My Bandit has triple pots which are rubbish in comparison.

[macca__macca]

@NZSpokes: that's what I'm hoping for by replacing my lines, pads and discs. I have no intention of replacing calipers and I ride like a grandpa anyway :-D


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