Front brake master cylinder for 7/8 inch bars

[Kickaha]

Ok had a look, says on the back of the master TCIC 5/8 on a little further on it just says 1
If this means anything

Have you never heard of imperial measurments? 5/8 = 15.875mm

Fuck knows why they use imperial but it isn't an uncommon m/c size

[DrunkenMistake]

Have you never heard of imperial measurments? 5/8 = 15.875mm

Fuck knows why they use imperial but it isn't an uncommon m/c size

figured it was 5/8 of a inch, wasnt sure if this was the bore size or not! haha cheers for your help man.

[DrunkenMistake]

http://www.trademe.co.nz/motors/moto...-435212620.htm
Would this do the job, bore size of 14mm

[nzspokes]

http://www.trademe.co.nz/motors/moto...-435212620.htm
Would this do the job, bore size of 14mm

No, stick with the stock bore.

Smaller bore will make the lever spongy. Remember its only your hand activating the brake.

Whats wrong with the stock one?

[DrunkenMistake]

No, stick with the stock bore.

Smaller bore will make the lever spongy. Remember its only your hand activating the brake.

Whats wrong with the stock one?

I dont think a 2mm difference in bore size will make a significant difference, MC is first then braided lines and new sintered pads, so by the time all that is done, I doubt ill notice the difference

[DrunkenMistake]

It's a 2008 model, must be made of cheese to need a rebuild by now! I just did my 24yo Honda's master a few months ago, only 40 bucks for a full rebuild too.

What are the symptoms? may be that something else is a problem instead/too. Also, upgrade to full floating calipers is likely to provide a big benefit, and may require another change in master if you do that eventually.

its an 05 model sold in NZ in 08 as new and it is a Hyo..
The rubber boot around the actual piston part has a hole in it, and once you get the boot off.. well shits just fucked..
I done a full strip down and clean out of the callipers yesterday, as I kept losing pressure in the front brake, assumed I had sticky pistons, they were grubby but not that grubby, resembled and spent most of today trying to bleed the system and purge the air out, with fuck all luck, pulled the top banjo out and tested the master, and it simply wasnt pumping out any fluid, and so it went from there.

[nzspokes]

I dont think a 2mm difference in bore size will make a significant difference, MC is first then braided lines and new sintered pads, so by the time all that is done, I doubt ill notice the difference

Its a 13%ish difference which in fluid terms is huge.

[nzspokes]

its an 05 model sold in NZ in 08 as new and it is a Hyo..
The rubber boot around the actual piston part has a hole in it, and once you get the boot off.. well shits just fucked..
I done a full strip down and clean out of the callipers yesterday, as I kept losing pressure in the front brake, assumed I had sticky pistons, they were grubby but not that grubby, resembled and spent most of today trying to bleed the system and purge the air out, with fuck all luck, pulled the top banjo out and tested the master, and it simply wasnt pumping out any fluid, and so it went from there.

So just put a kit in then?

[DrunkenMistake]

Its a 13%ish difference which in fluid terms is huge.

11.811% to be exact,

I feel as though im a broken record here,
I was upgrading the master anyway, rather than get a rebuild kit then replace the master in a couple of weeks I might as well get it now.

Its pretty stuffed, I was going to upgrade the master, lines and pads anyway but the master is in need over an overhaul/rebuild and for the frustration and cost of doing it, I might as well start by upgrading the master now..

[tigertim20]

It's a 2008 model, must be made of cheese to need a rebuild by now! I just did my 24yo Honda's master a few months ago, only 40 bucks for a full rebuild too.

What are the symptoms? may be that something else is a problem instead/too. Also, upgrade to full floating calipers is likely to provide a big benefit, and may require another change in master if you do that eventually.

its a 2006. regoed as an 08. symptoms are brakes suddenly stop working. I suggested he rebuild the calipers, which he has done. then they wouldnt bleed. he said that the issue previously was that he would pull the lever and nothing happened. I thought, well sounds like the MC is up the fuck. So I whipped it off, removed the lever, and the boot that covers the piston had a tear in it. pulled that off, and looked in the depression where the piston in the MC sits, and it was all corroded as fuck. a further inspection showed the corrosion was bad enough that solid shit had flaked off, and was causing blockages. a repair at this point would only result in future problems, and given that the issue is that the brakes dont work when the lever is pulled sometimes, its worth just upgrading.

Have you never heard of imperial measurments? 5/8 = 15.875mm

Fuck knows why they use imperial but it isn't an uncommon m/c size

fucking koreans!

Whats wrong with the stock one?

shits fucked bro.
upgrading size wise (a small amount) wouldnt be a terrible thing, hyo brakes are known for being piss poor even off the showroom floor, a bit more fluid displacement would actually be a good thing on the tank that it is

I dont think a 2mm difference in bore size will make a significant difference, MC is first then braided lines and new sintered pads, so by the time all that is done, I doubt ill notice the difference

2mm in diameter, remember its the surface area of the piston that displaces fluid, calculate the percentage difference and youll find its greater. seeing as your brakes suck shit anyway, going down a size, and reducing the amount of fluid displaced, well, your brakes will be even weaker than they are now

its an 05 model sold in NZ in 08 as new and it is a Hyo..
The rubber boot around the actual piston part has a hole in it, and once you get the boot off.. well shits just fucked..
I done a full strip down and clean out of the callipers yesterday, as I kept losing pressure in the front brake, assumed I had sticky pistons, they were grubby but not that grubby, resembled and spent most of today trying to bleed the system and purge the air out, with fuck all luck, pulled the top banjo out and tested the master, and it simply wasnt pumping out any fluid, and so it went from there.

I ran your vin and I got 06, but i think 05/06 are the same model anyway.

[nzspokes]

shits fucked bro.
upgrading size wise (a small amount) wouldnt be a terrible thing, hyo brakes are known for being piss poor even off the showroom floor, a bit more fluid displacement would actually be a good thing on the tank that it is

Righto, get it now. If it were me then I would get it bored and a stainless liner fitted which can be whatever you want. Then turn up piston to match.

[DrunkenMistake]

I ran your vin and I got 06, but i think 05/06 are the same model anyway.

Same diff, the master varies for the 06 between the one with the silver adjustable brake lever, and the plan old black one like mine, not sure what the full list of differences are, I know for sure the lever sizes and thickness are completely different

[tigertim20]

Righto, get it now. If it were me then I would get it bored and a stainless liner fitted which can be whatever you want. Then turn up piston to match.

this is one option, however he wants a remote reservoir for the look, which is fair enough. I dont see much point in spending money on a part that is shit in the first place.
its gonna cost $50-$100 to mess around with that, and if you increase the bore size, you have to be wary or remaining wall thickness. as well as that, there is an internal snap ring inside the bore, that holds the piston in (the piston is stepped) and prevents it from coming out further to prevent fluid leakage. machining the grove would be a pain in the ass.

For the cost he can just upgrade to a nicer item with the remote reservoir he wants anyway

[theseekerfinds]

I have used Good Spares and agree they are a helpful bunch down there.. I have also used Sweetstreet for spares and found them helpful too.. here's a Ducati 748 setup they have on trademe currently if that helps..

http://www.trademe.co.nz/motors/moto...-436595597.htm

[Tony.OK]

Don't forget that different masters may have different banjo bolt sizes and pitch too, could mean having to need custom made brake lines to fit each end once changed................more cost.