[Johnjohn]

I have noticed some treads about Tona's spongy front brakes and ****ty master cylinders - now it's my turn. I checked the master cylinder's inside and everythings looks as new...it's a 2000 Daytona 955i with 37000 on the clock- i changed the brake fluid with no result. There's absolutely no fluid loss in calipers or cylinder... Maybe it's time to admit it's a bad cylinder or what? I have had Adventurer and Tbird Sport with perfect brakes.
Any good advise out there?

John

 

[bradtx]

John, We've had really good luck by removing the pads, extending the brake pistons and cleaning the pistons with brake cleaner and a toothbrush. Ten to one you'll find one or more pistons per side that won't extend properly.

The major theory is something to do with the surface treatment of the pistons...I don't know, but the above procedure works very well.

Brad

 

[Johnjohn]

Brad

Thanks - will do right away. I'll let you know if it works.

John

 

[NotADuc]

One other thing you may want to try is using a plastic cable tie to hold the front brake on for a few hours. This is something I found on this site and it worked great for my bike.

 

[gazedrop]

The stock Nissan master is actually a perfectly good design... The common way to change it takes you from the stock 14mm bore to a 5/8" bore. The stock 14mm has more potential power than the 5/8", but at the expense of more lever travel.

I personally have no complaints with the stock piece, but admit I would swap it out with a 5/8" if stumbled across one for $20.

The stock lines on the other hand are a crap idea. Yes, they are a steel braid which is nice, but the crossover line that wraps over the fender -always- traps air.

Hang the left caliper overnight so that the tiny air bubbles can go up to the caliper (with the brake lever relaxed, of course.) Reinstall and bleed normally, after cleaning the pistons first as recommended previously.

 

[Johnjohn]

[/QUOTE]
The stock lines on the other hand are a crap idea. Yes, they are a steel braid which is nice, but the crossover line that wraps over the fender -always- traps air.

Hang the left caliper overnight so that the tiny air bubbles can go up to the caliper (with the brake lever relaxed, of course.) Reinstall and bleed normally, after cleaning the pistons first as recommended previously.[/QUOTE]


Thanks guys - i used all the tricks in the book and now my brake is rock hard - took the callpers apart and gave them a good overhaul - strapped the brake lever up overnight, and then found a new trick: with a polygrip pliers i press the brake pad agains the side of the calliper - opening the brake fully up - both sides and then pump the lever till there's pressure again - then i leave it strapped up over night for all the air bubbles to rise into the brakefluid reservoir - that solves the problem