Brake Bleeding Questions (5th Gen)

I printed out the 'how to' guide in the maintenance section. I did the clutch bleed w/ no problems.

Moving on to the brakes, I ran into a couple of issues;

1) The guide states that there is only one brake bleeder on the right caliber, however on my '98 (5th gen) non-ABS there are two bleeders on both the left & right claibers. Do I do both top bleeders & then button up the master cyclinder?

2) Where is the proportining valve located? It is not under the seat area anywhere. There is a metal cyclinder w/ brake lines attached on the right side located close to the fork leg. It has no bleeders on it.

3) Is the sequence for bleeding the rear caliber the same as the fronts? That is, bleed the top (front) valve first and then the center valve.

4) Do all of the circuits activated by the proportioning valve (the center bleeder on each caliber?) get their fluid from the rear master cylinder?

Thanks for any help. I don't want to screw up the brakes!!!

(I am posting this both in the 5th Gen area and in the Maintenance area.)

Sounds like the how to guide is for the 6th gen bike, which has a different LBS system than the 5th gen. You should check the service manual.

Personally, I just bleed the front brakes, I could care less about the rear brake. A lot less work that way too.

To answer your questions:

1) Yes, bleed only the top valves on both fronts, start with left side.
2) The proportion valve is under the seat, right side, upfront right near the tank hinge...lift up the rubber cover, mongrel placement.

(IMG:http://i118.photobucket.com/albums/o92/Resuam/Image.jpg)

3) The rear caliper will need to be removed {and yes, take the wheel off} You will need to invert it and place it on top of the rotor. Bleed centre then top valve.
4) Yes, the only time you will need the front master cyclinder open, and topped up is when undergoing step 1.

This is what I did a few weeks ago as per Haynes Manual using a vac. bleeder:

1. Bleed left front caliper, then the right, using the upper valves. Top up front master cylinder and cover. Done!
2. Now gain access to the rear m/c and top up the fluid.
3. Bleed the right front caliper {LOWER} bleed valve.
4. Bleed the left front caliper {LOWER} bleed valve.
5. Check rear m/c fluid and top up.
6. Gets a bit technical here, but I removed the front left caliper assembly, the one with the secondary m/c on it, and had to tilt it so that the m/c axis allowed any air to travel to the proportion valve. Also add material between the brake pads to prevent them from closing.

(IMG:http://i118.photobucket.com/albums/o92/Resuam/Image1-1.jpg)

7. Now bleed the PCV, some people have also reported to just squeeze the secondary m/c while bleeding to allow any air inside up to the PCV.
8. Top up the rear m/c
9. Bleed the rear caliper inner valve
10. Bleed the rear caliper outer valve
* Steps 9 and 10 should be done with the rear caliper inverted ontop of the rotor, as shown:

(IMG:http://i118.photobucket.com/albums/o92/Resuam/Image2.jpg)

11. Reinstal the rear and front calipers, top up the rear m/c and you're done.

Tips:
I did step 7 numerous times. I really love step 7.
Have 2 people, or a vaccum bleeder.
Buy at least 17 fluid ounces, or 1/2 quart of fluid... AT THE VERY LEAST. If I had to do this again, I would have bought double and used the left over to top up throughout riding etc. I got a bit anal about getting all the air out. After bleeding with the vac. I went and checked again by using the levers.

12. Good luck, and download the 5th Gen manual - http://www.vfrdiscussion.com/forum/index.p...s&showcat=2 (2 parts)

Thanks to all who replied. This is a great help.

That's why I love this board!!!

filterfool, Jun 26 2007, 08:35 AMThanks to all who replied. This is a great help.

That's why I love this board!!!

I have to second that (IMG:style_emoticons/default/fing02.gif) had the same quesitons pretty much. First night on the board and nothing but good things to say.

Vee-Ef-Ar, Jun 25 2007, 09:08 PMBuy at least 17 fluid ounces, or 1/2 quart of fluid... AT THE VERY LEAST. If I had to do this again, I would have bought double and used the left over to top up throughout riding etc.

I've always wondered, what is the shelf life of an open bottle of brake fluid? Everything I've read/heard is to ALWAYS use fluid from a sealed container. But really, if it was unsealed last week, is it okay? Does it last a month on the shelf? 2 days? I'm sure the opened shelf life depends on many things, mainly humidity--brake fluid is mostly alcohol, and alcohol absorbs water. But really, how long is it okay on the shelf?

Thank you for posting up this procedure. I'm looking forward to purging out what I believe to be the original fluid on my '99 (IMG:style_emoticons/default/unsure.gif) Also looking forward to slamming my hand in a door and scheduling that root canal...


-Rick

A couple of days should be ok, depends on the humidity of your shelf, brake fluid absorbs water pretty quickly.

Also depends how important your brakes are to you - brake fluid is pretty damn cheap so don't skimp !!

This is a good read, about brake fluids:

http://www.sportbikesolutions.com/motorcycle_brake_fluid.htm