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Discussion Starter #1
Ok, here goes..

Just flushed the old brown nasty wanna be brake fluid from my fronts brakes..

There was some sludge in the master cylinder. I wiped it out while there was still some fluid in there, so I shouldnt have sucked any down into the piston area.

However, while I have nice clear fluid now (have bleed the brakes too), and my 'sticky' brake lever is now not 'sticky', I have a lot of 'squeeze' avail. almost like it still has air in the system.

Could the master need a rebuild because I got rid of the mud it was using, and now the fluid can get past the piston seal? Also, does the rebuild usually just need new piston/seals, or should I look at getting a complete cylinder?

I have not yet ridden it to see if the braking effect has changed (they seemed pretty wimpy prior).
 

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Linkmeister Supreme
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The front brakes on these bikes can be a real nuisance to bleed.
Many have installed speed bleeders and claimed good results with less time and trouble.

Others have done a reverse fill by hooking up a hose to the brake fluid bottle and filling the system from the brake calipers up through the hoses to the master cylinder.

It sounds like your main complaint right now is a soft lever when you squeeze it, indicating air still in the system.
Before rebuilding the MC, try tying the lever back tight to the hand grip with a bungee cord and leave it sit over night or even a full day, then check it again to see if the spongy feel is gone and is firm now. This procedure has been reported to squeeze the air bubbles from the system.

Hope this helps. :)
 

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Worst brakes I have ever bled. Took me 4 days the last time to get lever pressure. Did the regular way, speed bleeder way, and tying off the lever way.
 

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..have a vulcan good day!
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Worst brakes I have ever bled. Took me 4 days the last time to get lever pressure. Did the regular way, speed bleeder way, and tying off the lever way.
What worked for me was the "Drip Method". Let it drip bleed (very slow drip) over night, refill in the morning.

:smiley_th
 

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Discussion Starter #6
try tying the lever back tight to the hand grip with a bungee cord and leave it sit over night or even a full day, then check it again to see if the spongy feel is gone and is firm now. This procedure has been reported to squeeze the air bubbles from the system.

Hope this helps. :)
ok, on this method, I assume the system is filled and sealed, correct? If I was to leave the master cylinder open overnight here in the land of humidity, I will be defeating the purpose of changing the fluid in the first place (we frequently have enough dew in the mornings it drips off the roof of the house like rain).
 

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If you guys are having that much trouble, Gravity bleed it like is necessary w/the uberexpensive silicone racing brake fluid.
Open the master cylinder, crack the bleeder, keep the reservoir full. Leave the brake lever alone. Leave the master cylinder open, covered so nothing can fall in it.

Don't get excited it will take a long time.
 

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Like all the above have stated...its just air....not sure about models after mine (1985), but I have brake bleeders everywhere, more than on later models I think....if you can drill/tap, and have done vehicle work before, you could add 2 bleeders down below (unless you have em)....if you do have em, remove them completely and replace/clean....they are more than likely clogged with yer brownish crud that aint soy sauce...
 

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Discussion Starter #9
i believe I only have 2 bleeders, one on each caliper. the additional ones your talking about would be down where the single line splits into 2, right?

I will have to double check that area to see if I have them.
 

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ok, on this method, I assume the system is filled and sealed, correct? If I was to leave the master cylinder open overnight here in the land of humidity, I will be defeating the purpose of changing the fluid in the first place (we frequently have enough dew in the mornings it drips off the roof of the house like rain).
Yes fill the reservoir and put the cap back on and then just zip tie the lever back to the grip and let it sit over night. any air left in the system can then work it's way up the lines and out into the reservoir. You can even help by tapping on the calipers and lines to help shake the trapped air loose.
 

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This is why I am a huge SpeedBleeder fan for all my vehicles. For $15 I upgraded my VN750 and it took 2 minutes to install the SpeedBleeders, then 5 minutes to bleed the front brakes. No issues, no air, no problem, no overnight drip, reverse purging, or other hoops to get it right. Simple solution to simple maintenance.
 

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Well before I became a Chopper Pilot, the flying not riding kind, I was a aircraft hydraulic repairman in the Army. So I used the same procedure that I did back in the day with aircraft brakes. We want service calipers, not just bleed them. Bleeding is the last step of the service. First open the bleed valve and flush the lines until you get clear, clean fluid. You need a clear tubing connected to the bleed value and the tube must go higher that the caliper or put a loop in it to keep air from re-entering the caliper. Take off the calipers one at a time, clean and use lube on the pistons, then use a C-Clamp, open the bleed valve and compress the piston clearing all the old fluid that you can. Be easy and don't over compress and damage the pistons. Run some more fluid thru while the piston is compressed until it's clear and no bubbles. Shouldn't take much and we are just flushing the piston at this time. Mount and repeat on the other side. Once this is done now we bleed each caliper. Just make sure that the MC doesn't run low and you should good to go. And while you are at it check to make sure all the connections are nice and tight. Don't want any leaks no matter how small.

I know it seems like a bit of overkill, but when I want to stop, I want to stop.
 

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I need to flush my front brakes also... but I haven't because I didn't want the hassle of bleeding.

Could I just keep pouring fluid in the m/c and make sure it doesn't run low until I get clear fluid... and would that negate the need for bleeding?
 

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Linkmeister Supreme
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I need to flush my front brakes also... but I haven't because I didn't want the hassle of bleeding.

Could I just keep pouring fluid in the m/c and make sure it doesn't run low until I get clear fluid... and would that negate the need for bleeding?
Well, opening the bleed valves to flush old fluid and get fresh fluid down to the calipers is exactly the same thing you would do to expell air from the hoses. So it amounts to the same thing IMHO. :)

Just a general shop tip here. If you ever get a bleed valve without a cap on the end so it is plugged with dirt, you can clean it out with a small twist drill bit twirled between your fingers. Had to do this once or twice on my old GMC truck and it works like a charm.
 
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