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Hard brake

Started by chiz, October 01, 2021, 08:59:34 AM

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chiz

Hey all I am guessing the the rock hard front brake lever is caused by a master that is too big. My bike has a 17 in wheel floating discs and blue dot calipers as well as steel lines. I somehow feel that if my master was still the Yam original my front brake might have a better feel....opinions welcome thanks.

red

Chiz,

Brakes are not optional.  For the price, I would try the OEM master cylinder, and see.  An eBay part can be a cheaper option, maybe.

Is the brake lever "hard" when cold?  This would be a problem.

Does the front brake get "hard" only during a ride?  If so, replace ALL of the brake fluid with the correct fresh brake fluid, then find out why the brake pads are dragging.  Does one rotor get hot before the other one?  That caliper or rotor may not be floating as they should, or the caliper piston seals may have hardened due to age, preventing brake pad retraction.  Check the brake rotors for warping.  Worn or damaged brake pads would need to be replaced, of course.

Keep us posted.
Cheers,
Red

P.S. Life is too short, and health is too valuable, to ride on cheap parade-duty tires.

Pat Conlon

Chiz, you are correct.
To get the best out of your blue spots (mono block) calipers you need a master with a 14mm or 15mm piston.
The Yamaha FZ-1 uses a 14mm master and the FJR (ABS) uses a 15mm master.

The oem FJ master cylinder is 16mm (5/8") and using this master will result in a hard lever as you know.

There are many other masters out there from other manufacturers that also uses a 14mm piston.

1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

Millietant

My FZ1 master cylinder made a big difference to the feel and control of my brakes. I have blue spot early R1 calipers, braided steel lines and 320mm discs on my FZR forks in the FJ.

My brakes are light years ahead of the originals in both power and feel.

Bryan (Waiex191) also upgraded with the FZ1 master cylinder and blue spots (even with rubber hoses) and he also knows of the improvement in braking quality that combination gives.
Dean

'89 FJ 1200 3CV - owned from new.
'89 FJ 1200 3CV - no engine, tank, seat....parts bike for the future.
'88 FJ 1200 3CV - complete runner 2024 resto project
'88 FJ 1200 3CV - became a race bike, no longer with us.
'86 FJ 1200 1TX - sold to my boss to finance the '89 3CV I still own.

Waiex191

Quote from: Millietant on October 01, 2021, 03:07:19 PM
My FZ1 master cylinder made a big difference to the feel and control of my brakes. I have blue spot early R1 calipers, braided steel lines and 320mm discs on my FZR forks in the FJ.

My brakes are light years ahead of the originals in both power and feel.

Bryan (Waiex191) also upgraded with the FZ1 master cylinder and blue spots (even with rubber hoses) and he also knows of the improvement in braking quality that combination gives.
Confirmed, my brakes are awesome now.  Easy enough to swap the MC.  I'd just do it.
Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL
 

chiz

Quote from: Pat Conlon on October 01, 2021, 10:32:04 AM
Chiz, you are correct.
To get the best out of your blue spots (mono block) calipers you need a master with a 14mm or 15mm piston.
The Yamaha FZ-1 uses a 14mm master and the FJR (ABS) uses a 15mm master.

The oem FJ master cylinder is 16mm (5/8") and using this master will result in a hard lever as you know.

There are many other masters out there from other manufacturers that also uses a 14mm piston.


NoNo the original master was replaced when I changed up the system what's on there is some cheap after market that looks almost like one you would find on Hon ST 1100. The original 84 Yam unit got binned. 

chiz

Quote from: red on October 01, 2021, 09:54:52 AM
Chiz,

Brakes are not optional.  For the price, I would try the OEM master cylinder, and see.  An eBay part can be a cheaper option, maybe.

Is the brake lever "hard" when cold?  This would be a problem.

Does the front brake get "hard" only during a ride?  If so, replace ALL of the brake fluid with the correct fresh brake fluid, then find out why the brake pads are dragging.  Does one rotor get hot before the other one?  That caliper or rotor may not be floating as they should, or the caliper piston seals may have hardened due to age, preventing brake pad retraction.  Check the brake rotors for warping.  Worn or damaged brake pads would need to be replaced, of course.

Keep us posted.   Hard and sharp from day one got used to it but miss that spongy feel of the old brakes

Pat Conlon

Look on the body. There should be a number. That will tell you the piston size.
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

Millietant

Quote from: Pat Conlon on October 01, 2021, 11:27:12 PM
Look on the body. There should be a number. That will tell you the piston size.

Just look on ebay for FZS 1000, FZ1, 2001 - 2005 master cylinder and you should find plenty at reasonable prices. I'd guess $30 will get you a decent one with the adjustable span brake lever too (I paid £30 for mine here in the UK).
Dean

'89 FJ 1200 3CV - owned from new.
'89 FJ 1200 3CV - no engine, tank, seat....parts bike for the future.
'88 FJ 1200 3CV - complete runner 2024 resto project
'88 FJ 1200 3CV - became a race bike, no longer with us.
'86 FJ 1200 1TX - sold to my boss to finance the '89 3CV I still own.