Spongey Brakes Grr

[w1_nny]

Hello.

My (grey) NC30 has a slow leak into the front brake system, which means I am forever bleeding the critters!

Its nigh on impossible to pin-point where this is happening - I think? Since it could be any joint/seal/pipe along the way. Unless I am missing a diagnostic trick?

Short of replacing all the seals (in the calipers and master cyl), every fitting and hose, can I ask if anyone else has suffered like this, and where the solution lay?

I figured it might be more common than just my bike! and could save a world-of-pain if I asked the question.

Thanks in advance.

[CMSMJ1]

Welcome to the site

I would clean it all up and then ziptie the lever to the bar overnight. In the morning you should have either rock hard brakes or an obvious leakage to spot.

It might be that you have a slightly loose banjo or a crush washer that has been crushed too much!

[Neosophist]

Have you tried tightening up all the banjo bolts?

If your on the original hoses still i'd junk them, they will be WELL past their best by now (I think honda recommend replacing rubber hoses every 5 years?) and get some braided ones on (which will improve brake feel) plus you'll be replacing all the washers with the new lines too.

If your still having problems after this might be a fluid seal on one of the pistons inside the caliper, not difficult to do, just a pain.

[Morespeedvicar]

Rebuild the calipers, it maybe corosion behind the seals. pump the pistons out, take seals out and clean the oxidation out of the seal grooves, pack the grooves with rubber grease and rebuild. If your lucky you may get away with cleaning up the seals as well.
Cheers
Ian

[w1_nny]

Thanks guys.

I'll try the rubber-band-on-the-handle-&-lever method and hope this throws up an obvious leak.

[razghost]

if that doesn't go well i could sell you my old braided lines on the cheap, only replaced them because they where too short when i replaced the calipars with cbr600 04 ones.

[CMSMJ1]

if that doesn't go well i could sell you my old braided lines on the cheap, only replaced them because they where too short when i replaced the calipars with cbr600 04 ones.

I'll have these matey if W1nny doesn't

PM me if cool

[Goinphaster]

If you have "build-a-line" kits where the banjos are seperate from the hoses- ditch them. that's where i had my problems, and I tried replacing calipers. after i replaced the lines with one peice types I was late breaking everyone at the track day.