Improving stock RZ350 brakes

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bryana
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Improving stock RZ350 brakes

#1 Post by bryana » Fri Aug 16, 2013 4:01 pm

I'd like to improve the front brakes on my RZ350 without using different calipers or master cylinder. I rebuilt the calipers, replaced the fluid, and bled the system several times but it still feels spongey. I have not rebuilt the master cylinder. I'm 99% sure there is no air in the system. I have done brakes many time on several bikes with great success. Not so much on the RZ. The hoses are original and the pads are old with plenty of material thickness. What options do I have for hoses and pads.

Thanks
Bryan

Ricino
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Re: Improving stock RZ350 brakes

#2 Post by Ricino » Fri Aug 16, 2013 6:07 pm

Hello and welcome to the board!

Get at least some steel braided lines, those aren't very expensive and they make a big difference.
Also slapping a little bit the lines will help some possible small bubbles to reach the reservoir, since those bubbles sometimes get stuck there. Rebuilding the master is sometimes necessary, there are new kits available from different sources.
Yamaha SZR 660 '96(4SU) ---> in the process to YPVS hybrid!

vmxwinn
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Re: Improving stock RZ350 brakes

#3 Post by vmxwinn » Fri Aug 16, 2013 6:29 pm

I can tell you what I did and it made a world of difference.

1. Change the master to 13mm bore unit. I used a mid 90's Honda that came off a CBR600 F3, this made the biggest improvement and looks very similar to stock. Ebay Cheap
2. Braided brake lines
3. Armstrong HH Sintered Brake pads Ebay

If you do these things you will be amazed how much better the brakes feel and the bike stops.
85 Y/B, Toomey pipes, PWK 28's, JJH Needle #2, 45 pilot jet, 145 main, Pods, VForce 4 reed blocks, +3 ignition, Milled head 1.1mm squish, R6 Shock, Progressive

Many Vintage MX Bikes, 03 ZRX1200R, 86 Moto Guzzi 1000 Le Mans MK IV, 86 VFR 750, 74 GT 550

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ricar
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Re: Improving stock RZ350 brakes

#4 Post by ricar » Sat Aug 17, 2013 1:25 am

I swapped the front end for a 2002 GSXR and found the gix breaks not actually much better than the RZ. I swapped to steel lines and was blown away. I thought it was hype but probably the second best change I made to the bike.
84 RZ. Half naked, SpecIIs, GSXR front end, FZ swingarm, SV rear wheel, trail tech speedo/tach

RuZty
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Re: Improving stock RZ350 brakes

#5 Post by RuZty » Sat Aug 17, 2013 8:55 am

What year/model/country?
I have an R6 radial MC, braided lines and Triumph Daytona calipers, all bolt on and all the braking you need for about $120.
('85 Canadian RZ)

bryana
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Re: Improving stock RZ350 brakes

#6 Post by bryana » Tue Aug 20, 2013 3:49 pm

Thanks. I'll plan on new lines, pads, and a master cylinder rebuild. 1985 USA model RZ350. Not sure about swapping the master cylinder. I need to retain the stock mirror mounting, threads, etc.

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Evans Ward
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Re: Improving stock RZ350 brakes

#7 Post by Evans Ward » Tue Aug 20, 2013 5:34 pm

Don't forget to replace the piston caliper seals too. The caliper pistons are also available OEM if needed but a bit pricey.
84 RZ350-Toomeys,SCR milled head, stk 26 carbs,300 M, 35 P, stock regrooved needles AS 2.5 turns out,stk air box,Banshee reeds Zeel non-progr CDI,TSRL Program YPVS,alum rad,R6 shock,GV emulators w/RT springs,fork brace,Shindy steering damper.

Bare
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Re: Improving stock RZ350 brakes

#8 Post by Bare » Thu Aug 22, 2013 11:44 pm

bryana wrote:Thanks. I'll plan on new lines, pads, and a master cylinder rebuild. 1985 USA model RZ350. Not sure about swapping the master cylinder. I need to retain the stock mirror mounting, threads, etc.
BE sure about swapping in a 1/2" Bore MC, it's the First and Best brakes improvement you could make.
ALL else follows. Hunt the Yama parts bin for such... they fit/support all the stock bits.

vmxwinn
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Re: Improving stock RZ350 brakes

#9 Post by vmxwinn » Fri Aug 23, 2013 1:06 am

Bare wrote:
bryana wrote:Thanks. I'll plan on new lines, pads, and a master cylinder rebuild. 1985 USA model RZ350. Not sure about swapping the master cylinder. I need to retain the stock mirror mounting, threads, etc.
BE sure about swapping in a 1/2" Bore MC, it's the First and Best brakes improvement you could make.
ALL else follows. Hunt the Yama parts bin for such... they fit/support all the stock bits.

That's what I said above, 13 mm bore master. Honda ones are cheap on ebay and look very simular to the stock unit. The are made by Nissin and have the same 10mm banjo bolt. Look for mid nineties CBR600, VFR,ST etc... Here is an example

http://www.ebay.com/itm/Front-Brake-Mas ... bf&vxp=mtr" onclick="window.open(this.href);return false;

http://www.ebay.com/itm/03-09-Honda-VFR ... 72&vxp=mtr" onclick="window.open(this.href);return false;
85 Y/B, Toomey pipes, PWK 28's, JJH Needle #2, 45 pilot jet, 145 main, Pods, VForce 4 reed blocks, +3 ignition, Milled head 1.1mm squish, R6 Shock, Progressive

Many Vintage MX Bikes, 03 ZRX1200R, 86 Moto Guzzi 1000 Le Mans MK IV, 86 VFR 750, 74 GT 550

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pepsi
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Re: Improving stock RZ350 brakes

#10 Post by pepsi » Tue Aug 27, 2013 9:21 am

I bought this cylinder and it does fit, used new Kevlar lines too. However my engine now needs a rebuild so I cannot comment on how it works, they did bleed OK

http://www.ebay.com/itm/SINGLE-DISC-DIS ... 7675.l2557" onclick="window.open(this.href);return false;
KR Y&B stocker with cats

vmxwinn
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Re: Improving stock RZ350 brakes

#11 Post by vmxwinn » Wed Aug 28, 2013 12:03 am

Looks like a copy of the Honda/Nissin master cylinder. If it is a 1/2" or 13mm bore master you will be happy with the improvement. :smt003
85 Y/B, Toomey pipes, PWK 28's, JJH Needle #2, 45 pilot jet, 145 main, Pods, VForce 4 reed blocks, +3 ignition, Milled head 1.1mm squish, R6 Shock, Progressive

Many Vintage MX Bikes, 03 ZRX1200R, 86 Moto Guzzi 1000 Le Mans MK IV, 86 VFR 750, 74 GT 550

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L.B
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Re: Improving stock RZ350 brakes

#12 Post by L.B » Wed Aug 28, 2013 1:23 am

If you need to keep stock then at least put new OEM seals etc in m/c & calipers. Best mod after that is as mentioned, braided lines is best.

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pepsi
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Re: Improving stock RZ350 brakes

#13 Post by pepsi » Sun Sep 15, 2013 12:04 pm

vmxwinn wrote:Looks like a copy of the Honda/Nissin master cylinder. If it is a 1/2" or 13mm bore master you will be happy with the improvement. :smt003


PISTON BORE DIAMETER 12.7MM :smt041
KR Y&B stocker with cats

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pepsi
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Re: Improving stock RZ350 brakes

#14 Post by pepsi » Sat Sep 28, 2013 10:14 am

pepsi wrote:I bought this cylinder and it does fit, used new Kevlar lines too. However my engine now needs a rebuild so I cannot comment on how it works, they did bleed OK

http://www.ebay.com/itm/SINGLE-DISC-DIS ... 7675.l2557" onclick="window.open(this.href);return false;
got the bike on its wheels, the lever is soft, might need to bleed it somemore, however it is more powerful.It should be good if I can get the softness out
KR Y&B stocker with cats

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steveloomis
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Re: Improving stock RZ350 brakes

#15 Post by steveloomis » Sat Sep 28, 2013 11:47 am

To get all the air out of the calipers, remove the bolts and turn it so the bleed valve is on top. The air bubble will purge out easily then. Others have said to put a tie around the lever and keep it engaged for a few hours as this will force the air towards the master cylinder where it can escape. I have not tried this but many have successfully. I always get in a hurry and "get'erdone"... :smt005
'81 RD350LC hybrid w/84 RZ engine. Zeel, Old style Toomeys, Yboot and filter 420 main 22.5 pilot, Air screw 2.5 turns out, DJ needle 2nd from top, Canadian VM26 carbs.
'85 KR/RZ US. Tank is seeping causing a blister in paint.....

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