Master Cylinder issues

A

Ally1

Member
Hey guys,

Have a question about the front master cylinder. I have a 03 GSXR 1000. I'm having a lot of issues with my front brakes and I believe the issues lies with my front master cylinder, the brake pads are good and the caliper is in good shape as well.

I'm thinking about replacing the front master cylinder and was wondering if I could buy just about any master cylinder to replace it with or does it have to be one that fits my bike? The reason I ask this is cause I believe the existing master cylinder on there is not the original master cylinder for the bike.. It is an OEM master cylinder.

The master cylinder I currently have on there is a nissin 3/4. Can this be replaced by another MC like a brembo but a different size? Will there be any issues with the calipers?

Thank you.
 
I think so. Know the bar diameter. I think they're the same. Piston size, don't go narrower
 
I have an OEM master cylinder from a 2006 GSXR 600 for cheap. PM me if interested. Thanks.
 
I have 2 2003 GSXR1000s (street and track) and have had both the GSXR600 and 750 of the same year. All I can say is the stock conventional master cylinder that comes with these bikes is pure garbage! Combined with the stock rubber lines and calipers and you get a set of wooden brakes that have no feel and fade pretty quick at the track.

For the street bike, I upgraded to steel braided lines and a stock radial master cylinder from an 04+ R1 or 06+ R6, the brakes feel excellent for street riding now, absolutely no complaints.

For the track bike, I went a step further and also put stock monobloc radial calipers from 04+R1 or 06+ R6. The upgrade is well worth it, the feel and braking power is fine, I have no complaints with this set up either.

In your case, I would at least replace the master cylinder to a yamaha one, they go for less than $100, and braided lines. Calipers you can get for about $150 if you're not happy after changing the lines and master cylinder
 
Mina said:
I have an OEM master cylinder from a 2006 GSXR 600 for cheap. PM me if interested. Thanks.
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That's one of the recalled units, and they're garbage. OP, do yourself a favour and buy a Brembo, and be done with it.

On my Gixxer ('04 750), I replaced everything, wave rotors, pads, lines, etc- but none of it made an appreciable difference until I added the Brembo MC to the mix.
 
Personally speaking, I had the OEM mc on my 06 750 with braided lines and they were fine on the street. My track bike had a Brembo master and it was one of the first things I upgraded. For the street, an OEM mc is perfectly fine. You guys are making this a bigger issue than it really is.
 
Rossi86 said:
I have 2 2003 GSXR1000s (street and track) and have had both the GSXR600 and 750 of the same year. All I can say is the stock conventional master cylinder that comes with these bikes is pure garbage! Combined with the stock rubber lines and calipers and you get a set of wooden brakes that have no feel and fade pretty quick at the track.

For the street bike, I upgraded to steel braided lines and a stock radial master cylinder from an 04+ R1 or 06+ R6, the brakes feel excellent for street riding now, absolutely no complaints.

For the track bike, I went a step further and also put stock monobloc radial calipers from 04+R1 or 06+ R6. The upgrade is well worth it, the feel and braking power is fine, I have no complaints with this set up either.

In your case, I would at least replace the master cylinder to a yamaha one, they go for less than $100, and braided lines. Calipers you can get for about $150 if you're not happy after changing the lines and master cylinder
Click to expand...
I am planning to do the caliper change too. Iam not sure of the difference it would make
 
Mina said:
You guys are making this a bigger issue than it really is.
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Mine decided to crap out on the back straight at Fabi after only a few morning sessions, so no- we're not making it a bigger issue than it is. Suzuki doesn't arbitrarily recall stuff unless there's a huge potential liability to them.
 
Rossi86 said:
At the track I notice a difference, but I'm also running Ohlins forks and a slick tire so that may offset the difference
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On my 04 750 there is only 2 bolts holding the 2 halves of the caliper together. I am not surprised it twists under tension. I have good brakes but not progressive & feels wooden.
 
RockerGuy said:
On my 04 750 there is only 2 bolts holding the 2 halves of the caliper together. I am not surprised it twists under tension. I have good brakes but not progressive & feels wooden.
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On my '04 750, I could easily lift up the rear end with a single finger. Stock calipers, but EBC pads, wave rotors, braided lines, and Brembo MC. The OEM calipers are actually decent, it's everything else they stuck on there that's crap.
 
99CBRF4 said:
On my '04 750, I could easily lift up the rear end with a single finger. Stock calipers, but EBC pads, wave rotors, braided lines, and Brembo MC. The OEM calipers are actually decent, it's everything else they stuck on there that's crap.
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After riding the Pro6 S1000RR at mosport last Wendensday, I'd say the brembo master cylinder is totally worth it. That bike would stop with no effort with just 1 finger light touch on the brake lever. I will be looking at upgrading my track front MC to a real brembo soon probably...
 
99CBRF4 said:
On my '04 750, I could easily lift up the rear end with a single finger. Stock calipers, but EBC pads, wave rotors, braided lines, and Brembo MC. The OEM calipers are actually decent, it's everything else they stuck on there that's crap.
Click to expand...
I was thinking of doing that but wanted to do the little things first
 
Rossi86 said:
After riding the Pro6 S1000RR at mosport last Wendensday, I'd say the brembo master cylinder is totally worth it. That bike would stop with no effort with just 1 finger light touch on the brake lever. I will be looking at upgrading my track front MC to a real brembo soon probably...
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Lol... The stock MC on an S1K will outperform your factory "Brembo" any day. But yes, you can't go wrong with an aftermarket unit.
 
OP,
look around and buy the R1/R6 master. It's a junior Brembo unit.
You should be able to get the master, lever, bottle shipped for $60. Check Ebay and the R1/R6 forums.

People part their bikes out or track guys sell off oem parts.
Add steel lines, bleed system properly, zip tie the the brake lever in overnight, leave cap off bottle a bit (let air out), don't seal the bottle.
Brakes should be awesome the next day.

Make sure your calipers are clean too.

good luck!

easy job to do
 
-D- said:
Add steel lines, bueno
bleed system properly, also bueno, and done properly, completely negates the need for anything you've listed below:

zip tie the the brake lever in overnight, nearly twenty years track experience, have never heard of, or seen anyone do this
leave cap off bottle a bit (let air out), and lets dirt and contaminants come in, no bueno. Also, just leaving the cap off doesn't squeeze air out of the system. Only proper bleeding does that.
don't seal the bottle. see above re: dirt and contaminants
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OP, what specifically is happening with your brakes? Are they strong initially, then fade quickly? If so, it's your MC.

If your brakes are just ***** period, your brakes may not have been bled properly, and there could be air bubbles trapped in your system. When was the last time you did any kind of service on your brakes?

If you're anywhere near Port Credit, PM me, ride by, and I can take a look one evening.
 
99CBRF4 said:
OP, what specifically is happening with your brakes? Are they strong initially, then fade quickly? If so, it's your MC.

If your brakes are just ***** period, your brakes may not have been bled properly, and there could be air bubbles trapped in your system. When was the last time you did any kind of service on your brakes?

If you're anywhere near Port Credit, PM me, ride by, and I can take a look one evening.
Click to expand...


PM sent.. thanks for your help.
 
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