Bleeding Screw for Brakes

I have been working on getting my front brake line primed up again on my 82 XJ650 and its been long and slow so far. Master cylinder never went dry but it is VERY dirty fluid in there. The thought of pumping for 5 hours to get to new fluid just does not seem much fun. I saw these on BikeBandit and wondered first if anyone has tried them, seems handy as heck to me! and second, just what size is that bleed screw??? I think its 10mm but they also offer 7mm and 8mm. Any ideas?

Bryan

 

ooops, forgot the link...

http://www.bikebandit.com/product/1597?m=8214&t=1

 

The bleed screw on my 550 is 8mm, but... that might not be relevant.

If the other thing you're talking about is a vacuum pump, I've heard other people around here say they're very handy!

 

I saw the pump thing from a post Ric made. These look like something that replaces the bleed screw that is in there. Kind of a neat idea if I'm reading it right.

 

Speedbleeders ROCK! Worth every penny. Makes bleeding the brakes in the future a breeze for one person. Pretty sure all XJ's use the same size - M8x1.25
Part # SB8125L (Speedbleeder) - not sure of the Goodridge or Russell part #

Now - as you want to change the fluid entirely, you'll definately want to go the vacuum pump route. Combined with the speedbleeder, it'll suck out the old stuff quick & easy.

 

Thanks for the tip Altus! I went to the local parts stores (Oreillys and Autozone) and got a speed bleeder. The didn't have the metric M8 but they did have a 5/8 that is supposedly the same. Guess I'll find out tonight when I get home and try it.

Saw a vacuum pump (mightyvac) but it said Automotive pump. Guy at the store told me its not for motorcycles but I am not sure he even knew what it was. Anyone know if there is one specifically for bikes or are they all the same?

 

Mityvac does make one specifically for motorcycles:

part number MTY-6820

as listed in Carquest catalog... cost $34.50 US the last time I checked.

 

You don't need a vaccum pump or speed-bleeders. Try this:

HOW TO BLEED YOUR BRAKES WITH A SYRINGE

This method works on the principle that air bubbles rise in a fluid – so you are working with gravity (rather than against it) to eject any air through the reservoir. The bleed nipple on the caliper is usually the lowest entry point in the brake line system, so this is the point where the fluid is introduced.


1. Go to the local chemist and buy a 20cc syringe. Tell them it’s not for drugs. These are about $1-2 each (the syringes, not the drugs).

2. Get yourself some clear hose – the same stuff you probably have used for normal brake bleeding duties. Cut a piece that’s about 10-15cm long and push this on the end of the syringe. Now you are ready.

3. Open the reservoir cap and suck out the old fluid (if any) with the syringe and tube. Discard this fluid.

4. Place a suitable ring spanner on the caliper bleed nipple (normally 10mm). Make sure it has enough "swing" room to open and close the nipple (about one third of a turn).

5. Fill the syringe about 3 quarters full with fresh fluid (straight from a new bottle). then hold the syringe upright and draw some air into it, clearing the tube of fluid.

6. Push the tube over the bleed nipple. Facing the syringe down, open the nipple slightly and draw a SMALL amount of fluid out of the caliper with the syringe. This will fill the tube with fluid and allow any air to rise to the top of the syringe. Don’t draw too much or you will suck air into the master cylinder.

7. With the caliper nipple still open, push the fresh fluid from the syringe into the caliper. Be careful not to push any of the air from the syringe back into the caliper. When this is done, close the nipple and remove the tube (a good tip here is to close the nipple and draw the syringe – creating a suction effect in the tube over the nipple. Remove the hose and any remaining fluid will be sucked back into the syringe. Nice and tidy).

8. Repeat the process from step 5. Keep an eye on the reservoir level – if it approaches full, use the syringe to remove the fluid as per step 3 (if you’re stingy enough, you might re-use this fluid for your next attempt at step 5).

9. If you have twin calipers, move to the other caliper and start the process again from step 5.


You can also use the syringe to draw fluid out of the caliper. This is handy when you are bleeding the system from dry, as there will be air in the caliper above the brake line entry point that you won’t be able to push back up the line.

With a bit of practice, you will find that this method is the quickest way to bleed a brake system – and you will use minimal brake fluids in the process.

 

Begin by using Rubber Syringe and evacuating the entire contents of the Master Cylinder.

Spray Brake Kleen in the Master Reservoir and evacuate it.
Use Kleenex to absorb the Cleaner and remove grime.
Use Clean, fresh fluid and fill the reservoir 3/4 full.

Extract the Caliper Bleed Screw furthest from the Master
Wrap its threads with Teflon thread tape to make for an air and fluid tight seal
Pierce the hole in the Bleed screw to allow fluid to pass through.

Using a "One Man Bleeder Tool" bleed the Brakes
Fill a small Jar with enough Brake Fluid to immerse the One-way Valve and to allow you to see air bubbles.

Pump fresh fluid through the One-way valve until that which is coming out of the line is as clean as what your are replenishing the reservoir with as you force the Brake Fluid down through the system.

 

Thanks for all the tips guys! I saw the speedy bleeders but the local stores only went down to M10 and not M8 soooo I bought the quicky vac. Damn was that worth the $30!!! Once I figured out how to NOT pull fluid into the vac I primed the whole line in 5 mins with new fluid. Best tool I bought yet! Going to order those speedy bleeders but wanted to get this done this weekend. Guy is coming to clean the carbs next week and new tires are here. After 1 1/2 years of puttin this thing back together I am almost ready to go!!! This time next week I should be on the road

:lol:

 

Some models use an m7 sized screw...I believe the 750 Maxims, and maybe the 650 Turbos, too.......

Also, do NOT use a speedbleeder when trying to fill an empty system (changed brake lines, or rebuilt the pistons, etc.) You'll NEVER bleed your brakes! The spring loaded valve won't ever pop open to let the air out, as the spring is "stronger" than the air being compressed in the lines.

Guess how I found this out............!

 

chacal I'm glad you told me! One of the things I want to do soon is replace the original lines with the braided ones. Guess what I would have been doing forever.......