tomzxt

I'm sure this has been covered somewhere so don't kill me too much for a repost. Tonight I had some spare time and wanted to change out my brake and clutch fluid since it was the original fluid from '98. I browsed through youtube.com and came up with these very helpful videos. I had the front brakes and clutch fluid changed out in about 20 minutes first time. Feels much better now. Only thing it doesn't cover in the video but is in the comments is what to do if the fluid is barely coming out which mine was in the brakes. Enjoy!

YouTube - ‪Bleeding a Clutch NSR Tech‬‏

YouTube - ‪How to - change brake fluid‬‏

YouTube - ‪How to - change brake fluid part 2‬‏

McSuperchicken

Right on def what I needed to find

00SUPERHAWK

Just did mine, Clutch, F/R breaks. Levers and pedal feel much better.

Here is what came out....YUCK!!!

Kelevra

Doing mine shortly.

bigborer

Anyone knows why the front brake is impossible to bleed? No matter how much I pump there is no lever pressure felt, and liquid comes out perfectly clear (no bubbles) out of both calipers. What do you think? Some air strangely got trapped? Bad master cylinder? I've read somewhere that with old bikes you could damage the master seals by using the lever all the way as there might be corrosion on the unused parts of the master cylinder.
This is not my first brake bleed...
ps:it worked ok before

Wolverine

Pull your master cyl apart and meticulously clean it. You may also have a chunk of junk blocking your line, etc. The system needs to be clean, really clean. At this point in these bikes lives, the hydraulic systems are more than likely built up with junk if they haven't been properly cared for all their days. A rebuild kit sounds in order here.

bigborer

Thanks!

I'll clean the MC... also the brake pistons are extremely hard to move though the seals have allegedly been replace 2y ago, perhaps the mechanic didn't apply rubber grease or cleaned the pistons properly. Remembered that the rear brake also acted up like this, and it got working properly after removing the piston, cleaning and applying rubber grease. Perhaps it's a combination of factors; with the hard to move pistons and the old master cylinder seals.

Out of desperation I tired to pump the pistons out using the grease gun- it works but I'm still left with 2 pistons inside the caliper. I'll get the GF to pump the grease gun while I'm holding the empty cylinders blocked with... something, perhaps that'll pump enough pressure to get the remaining pistons out.

There are different part numbers for 98-04 and 05 MC rebuild kits, and in stock locally there's only the one for the 05 model (which shouldn't fit my bike).

I'm getting really really really desperate, on Friday I am supposed to leave for a road trip and now I don't have brakes on the bike... The lines are Venhill and brand new- wanted to swap them before the trip just for piece of mind (the old ones were gray and bulging with pressure)... Another route would be getting the widely recommended f4i master + calipers, but those will almost surely come with the same issues, and I'm not sure I could get them in time. Don't know what else to do... I can't describe how much I wish to have this bike fully functional for this trip

Wolverine

Check out this technique, it's a good one.

You can simply unbolt the caliper 1/2's for more room to work.

bigborer

Thanks! That is a life saver, it should be made sticky!

Funny thing- I have used that trick before but had completely forgotten about it- main thing is having a socket of proper size. My usual method (which failed for the VTR) is using a circlip remover with the tips covered with vacuum tubing.

Now, I have one caliper done using the grease gun method (extremely messy) and one caliper partly done (only the smaller pistons) using the method pictured in the video- tomorrow I'll do some more searching for sockets.

bigborer

Finally found the culprit- check out this MC boot... thank God I found it, I really dodged a bullet with this one.

ps: the internal gaskets were also bad- not perfectly round and the reservoir fluid port partly obstructed with little flakes of rubber. Apart from dirt, there was also a lot of calcification, likely from water that got in through the broken boot. Probably, in a life or death situation, after proper cleaning, some compressed air through the reservoir port, and a lot of rubber grease, it might have been able to be pump a bit of pressure... for a little while.

Arranged to meet a guy tomorrow for a set of f4i MC + f4i calipers- he swears they're in excellent shape but I've also ordered rebuild kits for both front and rear MCs which I'll be picking up on the way, just in case. I'll fit the MC tomorrow and install the calipers at a later time, after grinding them down to fit and getting new seals and pads. The rear MC is surely in a similar condition, I'll rebuild it's MC and fit steel braided lines by next month. And then the clutch...

Wolverine

Is that the boot that keeps debris out of the master @ the lever?

bigborer

Yes, it is.

E.Marquez

Culprit to what? Its just a dust boot

bigborer

Culprit as in "this MC is broken", as I described in my message

bigborer

Update:
Got the F4i calipers and MC. Fitted the MC- after about 20 pumps it got where the old MC got after 1 hour of pumping... Got it to maybe 95% bled, perhaps I'll tie the lever closed overnight for the rest, but regardless, it's still much better than any bike of 10+ years and OEM lines I've ever ridden.

Wolverine

I use the original MC and the F4i's w/ EBC HH (w/ ss lines) and I have plenty of power and modulation.
Glad ya got it sorted. Letting it sit over night will help, after all the movement it takes a while for the very small bubbles to collect. I've found it's not necessary to tie the lever.

E.Marquez

To get those fine bubbles out if you do not have a high volume low pressure bleeder, try vibration and changing the angle of the bike.
Vibrations :Use an electric drill....r some other electric device that when running make high speed vibrations, ask your wife she may have an idea....lol
I use a air powered extended die grinder and a old ball bearing that I made a spindle for that fits the die grinder.. That way i can transmit the vibrations to the line, caliper, MC with indirect contact.

vibrate the line for a min, change angle of bike brakes ... get those low points and trapped air bubbles a way to escape and move up to the MC, SLOWLY squeeze and let the lever release a bit faster... that cycles fluid in and out of the MC valve/ piston/ reservoir and you will get air to escape though the return port in to the reservoir.

Labor and time intensive for sure, but works as well as a expensive to buy, and use high volume brake bleeder.

bigborer

I might try to use an orbital sander over a sponge (to prevent scratches).

Funny thing- the rear brake gave up as well. Twice. It's amazing how many hand gestures are needed to say "I need an 8mm wrench, some brake fluid and a rag" while in a foreign country where they barely speak English.
After bleeding it, the first time it lasted about 400km, the second time about 150km. There are no leaks so I can only assume that the rear MC is broken as well. Hopefully the rebuild will cure it.

Wolverine

Sounds to me like the systems could use seal replacements; masters, slave and calipers.

E.Marquez

Master cylinders and slaves need a rebuild...your passing air someplace.

CaryDG