spongy brake lever

[Drunkn Munky]

Ive fitted some braided lines to my rvf and i cant seem to get any decent feeling back in the lever, it wasnt too bad before but now its crap, the lever comes right back to the bar.
ive tried vacume kits and the traditional way and yes i am doing it properly, i done the lines on my gixer at the same time and their perfect, didnt cause me any problems at all.
could there be a problem with the master cylinder and are these rebuildable?

[wullvfr]

im having the same problem at the moment.....but its worse than being spongy there is nothing at all.usually its down to air in the system but if you are doing it right then my money is on the master cylinder.they are rebuildable and you can get a kit from wemoto £30 which has everything you need.every now and then there is master cylinders on ebay at okay prices,there is some at the moment on ebay shops(additional buy now items)but they are all going for around £30-£40......
ive bled mine 3 times and tried different lines and calipers so im going to replace the m/c and hopefully that will solve the problem.before i put the bike off the road the brakes were starting to go spongy so i think this was the early signs of the m/c packing up.

[monkeywithaplan]

if you were brakes were working on bike recently and you just stuck on the lines, and are now having trouble i guarentee you just have air trapped.

i spent 2 hours trying to bleed my standard RVF calipers from dry, after sticking on the braided lines. a nice wee trick someone on here gave me was to push the pistons right back in, and keep them there while bleeding. this will force the trapped air behind the pisons back up the line so you can bleed it out.

persevere. you will get there.

[Drunkn Munky]

thanks monkey ill try that, god knows ive tried every other trick in the book!!
the bike had the original hoses on before hand and feel was poor to say the least. I spose theres no easy way of doing this you can have to keep going till its right, ive nearly gone through a whole bottle of brake fluid trying to get some feel back in these brakes.
If all else fails then ill rebuild the MC.

[arsey30]

When you say vacuum kit, what was it.

I found a syringe connected to the caliper bleed nipples, used to suck the fluid down, worked quickly, I spent ages before with no results.

Dave.

[wullvfr]

i might try that.......ive got a m/c coming but if that doesnt solve the problem then i will give that idea a bash........im confident my m/c is goosed though.

[fastdruid]

Ok, here is my 'ultimate' bleeding guide, it's a bit of a pita but has never failed me.

Firstly if fitting new lines then do step 1 before removing the old lines and ensure the caliper is filled with fluid before you reconnect the lines, then when you push the pistons back in it will fill the line with fluid (or at least partly) and then you can bleed as normal.

1) Remove calipers from the mounts (obviously leaving lines connected), remove the pads, put a large spanner (or similar) in between the pistons, stick it on the side stand, stick the bars fully to the left, pump the brakes until the pistons touch the spanner.
2) Bleed it until there are no more bubbles.
The level in the m/c res should be on low before you do these next steps otherwise its fluid everywhere
3) Move the calipers around so that the pads (if fitted) would be horizontal with the inner side facing upwards.
4) Tap the caliper a few times, tap the brake line a few times, tap the M/C and banjo a few times.
5) Push the inner pistons in, leading ones first.
6) Move the calipers around so that the pad would be horizontal with the outer side facing upwards.
7) Tap the caliper a few times, tap the brake line a few times, tap the M/C and banjo a few times.
8) Push the outer pistons in, leading ones first.

If you replaced the lines bleed you might want to bleed again.

9) Replace pads, remount calipers.
10) Pump brake until pads touch and lever feels right.
11) Top up brake fluid
12) When you put it away overnight pull the lever as hard as you can and cable tie it in the full on position.
13) Remove cable tie and enjoy your brakes!

Druid

[Drunkn Munky]

When you say vacuum kit, what was it.

I found a syringe connected to the caliper bleed nipples, used to suck the fluid down, worked quickly, I spent ages before with no results.

Dave.

Yea tried that one, i also got i mitivac kit, i use that to get the fluid running all the way through the lines then use the traditional method to finish things off. It worked a treat on my old CBR 6 and my current Gixer but i just aint having no luck with the RVF.
If i do go the MC route then i may just get SP1 calipers with SP1 MC and kill 2 birds with 1 stone.

[monkeywithaplan]

When you say vacuum kit, what was it.

I found a syringe connected to the caliper bleed nipples, used to suck the fluid down, worked quickly, I spent ages before with no results.

Dave.

Yea tried that one, i also got i mitivac kit, i use that to get the fluid running all the way through the lines then use the traditional method to finish things off. It worked a treat on my old CBR 6 and my current Gixer but i just aint having no luck with the RVF.
If i do go the MC route then i may just get SP1 calipers with SP1 MC and kill 2 birds with 1 stone.

lol, i ended up getting 1999 fireblade calipers and master cylinder. 5 mins bleeding from dry. most amazing feeling after all the fcuking about with standard calipers, haa haa

i would keep on re-using brake fluid(if its clean), untill all air bled out, and when your firm feel is there, bleed some fresh from the bottle brake fluid through. saves you a fortune on bleeding through litres of the stuff and dumping it :)

[Neosophist]

You can also with the help of a friend, hold the brake lever in and with a rag around the banjo on the resevoir gently open the nut ever so slightly to let a bit of fluid out, tighten it back up before the lever is all the way in.

For some reason air always seems to get trapped here.

Hope thats of some help if you havn't got it sorted yet.