Help with Brakes?

[robeel]

Hey guys, about 1.5 years ago i upgraded my 35's brakes with braided lines & 600rr calipers, still has the 35 MC. I hadn't ridden in about 2 months when i got the bike back but the brakes felt great & what i remembered a big improvement.

I also had a tyga mini reservoir put on, about 6 or so months ago i noticed brake fluid getting low which never happened before. Topped it up, 2-3 months later same thing again, it's been a few months & the level seems alright. But recently the brake doesn't seem right like it's not stopping as good, might be in my head cause the fluid & tyres are shit but don't think so.

The lid on the tyga mini reservoir looks a bit warped & felt like there's a small leak around the lid. I don't think there's a leak anywhere else but not sure. also the carbon lid looks to be bubbling/peeling up a little in a few spots, think the fluid might have done it?

Could this be a problem with the tyga reservoir lid not sealing good? Anyone else have this issue?

might grab another lid from tyga see if it helps?

[RoninZX-10R]

How long has it been sinced you flushed the brake system and put in new fluid? I'm wondering if because the bike has been sitting unused for so long the brake fluid has absorbed moisture.
I haven't had any experience with the Tyga reservoirs, but do you have the original reservoir? If so I'd try changing it over and see if you still have the issue.
Have you checked along the hoses to make sure it doesn't have any cracks (asuming you have the original rubber lines?)?
One way to check for leaks would be to pull in the brake lever and tighten a plastic cable tie around it so the system is pressurised. that should show up any leaks pretty quickly.

[Ben_OB1]

Hi Robeel,

To me it sounds like the seals in your original NC35 master cylinder might be shot. It sounds like you're getting fluid back to your reservoir (pressurising it) and causing it to leak. Normally there will be no pressure in the reservoir, it is designed to tolerate a reduction in fluid level but not an increase.

This would explain the deteriorating performance of your brakes too. Are you aware that most people who do the 600RR conversion also upgrade the size of their master cylinder too? Instead of refurbishing your NC35 master cylinder you could consider an upsize, maybe a Brembo radial arrangement

I do not recall the bore size of standard NC35 and 600RR master cylinders, but do a Google search and you'll find it quick smart.

Ben.

[Cammo]

Is there a chance your brake fluid got so low that air entered your master cylinder? If so your front calipers will just need bleeding to get the air out.I would do this anyway (using new fluid) after a good lay up.

I use an 11/16 master cylinder with my SP1 calipers, 11/16 is standard size for the early (non-radial) 600rr calipers.

[robeel]

about 1.5 to 2 years ago was the last time the bike was layed up, had a bit of cosmetic damage so decided to spend a bit & fix it up right. Had the guys at rb's do full exhaust/carb tune, valve clearances, brakes, braided lines, rr calipers, mini reservoir & bleed. brakes were awesome when i got the bike back, since then i've been riding at least once a week, most it hasn't been used is two weeks.

All of a sudden about 6 or so months ago it started dropping fluid. I tied the lever back the other day as i read it can help get air out, next day the only leak i could find was around the mini reservoir. Seems to be seeping out from the sides of the lid.

I was told the 35 MC would be fine with the 600 calipers by the guy i bought it from i think it was graeme from gf racing, he was using them with a 35 MC on his race bike & rb racing said will be cool too.

How much would a brembo MC be? maybe for the future... if there's a problem with the MC i'll try to grab a 600rr one.
Would there be much of an improvement in braking with the 600rr MC over the 35 one?

I think they're 03 calipers, so i could use 03-06 MC? & do other honda models use the same MC i could use with the rr calipers? in case i can't find a 600rr one.

Cammo, I wouldn't be surprised if there's air in the MC as the fluid was down to the low marking. But still doesn't explain the sudden drop in fluid?

I've never bled brakes before but read it's pretty easy, Is there a bleeder kit & guide for dummies?
How much fluid will i need? I've got a motul 3&4 500ml minus filling the mini reservoir up twice.
Do you recommend getting a 600 MC too?

Before i bleed the brakes i'll grab a new lid & rubber piece from tyga, if there's still problems after new lid & bleeding i'll put the old reservoir on if i've got it.

Damn i finally just got some new tyres delivered i was hanging to put on & try out after putting up with the old dunlops. will have to wait...

[Neosophist]

fluid naturally goes down as the pistons come out more and pads wear.

Unless you have a leak, (put some tissue paper around all joins and cable tie the handle overnight) then its probably this.. you will notice it more with a small res as there is less fluid so it looks like its moved quicker.

There not a sealed unit either, theres space for air to come in and go, hence why you change the fluid as moisture / water gets in there.

[robeel]

so few nights ago i tied the lever overnight & wrapped some tissue paper around banjos... next day the only leak i found was around the tyga reservoir lid. Good thing is the brakes feel better, bike has been stopping really good.

could this just be a dodgy reservoir lid rubber gasket? as the lid does look a little warped, everything was fine for over a year though...

I'll grab another lid & will have a go at bleeding the brakes in the next few weeks anyway as its been about 2 years & the fluid is looking a little dark.

Another problem is my speedo stopped working, cable spins though it could probably use some lube. Think it's the speedo drive plastic nut, looks a little worn, had some shaved plastic in the housing & doesn't seem to be spinning, holding tightly on the small metal rod.

where can i get the plastic nut?

can i just spray some lube down inside the cable or so i need to take it out? & what lube do you guys recommend? is it possible to use chain lube?

btw anyone from around sydney that has stands they want to sell let me know, especially a rear one.