Brake bleeding

[Dirty Dave]

I've succesfully bled brakes before after installing new lines, etc. This time I can bleed out air and pump up pressure but I can't keep pressure for long. Do the copper washers have to be new each time a new install is made? Can teflon tape help on threads or are the washers enough? I've changed the master, calipers, lines & always have the same result....................

[Ricky-D]

"Pumping up pressure" indicates there is air remaining in the system.

Reusing washers isn't recommended but can be done.

Losing pressure would also indicate a leak in the system. Inspection is called for, to find the leak.

Always bleed the caliper that is farthest from the M/C first.

***

[R J]

NO teflon tape.

Change out the squash washers anytime you take one apart has always been very effective for me.

[Dirty Dave]

Thanks for the tips. Wouldn't a leak show up as brake fluid somewhere? No air  bubbles show up when bleeding. I'll try all new washers.

[sandy]

Use a Mity Vac brake bleeder. It'll improve efficiency in getting all the air out. Sometimes an air bubble will get stuck near the banjo bolt and not get all the way down to the caliper. After bleeding and waiting a while, hold pressure on the lever/pedal and crack open the banjo bolt. (Lots of plastic on painted parts). That may get that last stubborn bubble.

[Dirty Dave]

I used the Mity Vac. I'll try the banjo bolt method....... A friend had a hard time as well and jiggling the bike around helped.

Thanks all.

[Ricky-D]

Thanks for the tips. Wouldn't a leak show up as brake fluid somewhere? No air  bubbles show up when bleeding. I'll try all new washers.

Sure, a leak will be fluid - just have to look harder.  The lack of air bubbles do not indicate a lack of air in the system.

It's all in developing a good technique for bleeding the brakes. You may simply be moving the air bubbles around inside the system.

***

[Hondasan]

you can also adding fluid botton up- put fluid in the bleeger with a big syringe (with no air in it !)
air bubbles go up easier then down- so you can clear a stuck bubble easier

[txhood]

Also, use a bungee cord or rubber bands to hold pressure on the brake lever.  Let it sit over night.  If there is air in system it will migrate to m/c reservoir.

[quexpress]

you can also adding fluid botton up- put fluid in the bleeger with a big syringe (with no air in it !)
air bubbles go up easier then down- so you can clear a stuck bubble easier

That's the way I have been doing it for quite a while. Works for me! 

[Robert]

If the lever goes down slowly and keeps going down then there's a leak if it goes down slowly and stops midway could be air. You will have a hard time seeing the leak because it wont be much fluid maybe like a few drops and that could adhere to the lines and follow them down. Crush washers should be changed every time but if you tighten tight enough they should seal the problem knowing when you are tightening to much. As said before no tape.

[FLAVALK]

Are you talking about brakes or the clutch? I know you said brakes...but I'm just sayin...While the process is the same, I have found that you must stay after the clutch as it takes longer...perhaps due to the longer line. I have reused the seals several times without issue

[Sodbuster]

Heat up the copper washers till they're red hot with a propane torch and let them air cool .... this will temper the metal and make them SOFT again.

[Dodis]

I think Sodbuster is onto something there, when in a pinch for washers. But, from my reloading experience and instructions, the annealing process for brass (should be similar for copper, being a component of brass) is to heat it to just a dull red, best seen in a dim room. Then drop it into a bowl or bucket of water to cool quickly to soften it. Overheating starts breaking down the copper, and working it (flexing, etc.) hardens it.

It is the opposite of annealing steel, as it requires heating and slow cooling to soften.

Mike

[Patrick]

I'm not quite sure what you mean by not being able to keep pressure for very long.. If your bleeding automotive style then I would suggest starting at the master and bleed the heck out of it, then move to the farthest point and work back.. Since you have done this before then I'm sure you know that the lever can't be released until the bleeder is tightened,, one little slip and it means starting over[stuff happens, it happens a lot around me].. Throw that teflon tape away.. If this doesn't seem to work then pushing fluid from the bottom may help, just crack a lever and push away.. Things could get messy so don't let the paint get any fluid on it..

[Sodbuster]

Here you go ....

Copper Annealing	powered by Aeva

[Dodis]

Video didn't want to come up, but I searched up a few other links to further my education...  

http://en.wikipedia.org/wiki/Annealing_%28metallurgy%29 about annealing in general.

I did find that just heat and let cool is fine for copper/brass/steel/silver.

The water quench is more of a reloading addition to the process to prevent annealing of the case head for safety reasons related to the firing of the shell. I had never found that part of the description in the numerous readings I have done on annealing, until I found a few more sites today.

http://www.6mmbr.com/annealing.html describes the case annealing and later explains why not to anneal the case heads.

That's the great thing here, the exchange of info makes for a learning experience, even if not Valk related!

Thanks, Mike

[Dirty Dave]

Been away for a few days but thanks for all the ideas.

I mean by not being able to keep the pressure up, I can pump good functional brake pressure up by pumping the lever a few times. Three seconds after I let go the lever, I have to start from justabout
scratch. No visible air bleeding out. I will try adding fluid from the bleeders. I'll heat treat the washers
if I start over with the steel braided lines I first put on but removed 'cause I thought they might not be
sound.     Thanks again guys.......

Dirty Dave from Montreal