frEEk
Administrator
ummm... yeah
Posts: 9660
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posted August 17, 2007 04:47 PM
filling/bleeding an empty brake system
so i just had the rear caliper revuilt and am trying to fill the now empty brake system with fluid but... IT ISNT TAKING IT! the master cylinder SEEMS to be all right, or at least the lines to it are full. no bubleds appear when pumping the brakes, but there is NO fluid being pumped thru past the master cylinder. i can pump to my heart's content, either with the bleeder wide open or with it closed then opening, and nothing is moving. there some trick (and i dont have a speed bleeder) to getting the fluid to flow? tried gravity bleeding for some time and nothing appeared to move either. or does the pedal need to be bottomed out for gravity to work?
   
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tcchin
Zone Head
Posts: 867
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posted August 17, 2007 06:17 PM
Draw the fluid through the caliper with a Mity-Vac or equivalent.
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dougmeyer
Needs a job
moderated
Posts: 2713
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posted August 17, 2007 06:25 PM
FrEEk,
Are you opening the bleed valve on the downstroke and closing it before releasing the lever ? If not ,you won't get anywhere. Forgive me if you knew that.
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VincentHill
Needs a life
Posts: 6520
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posted August 17, 2007 06:31 PM
Actually I do what they do in Detroit! I fill the Master Cylinder from the caliper! I take one of the Old Pump Squirt cans and clean it out with Brake cleaner then Brake fluid (Pump through the can) then fill it with the Brake fluid. Using a small plastic tubing (The Kind that used to be on Batteries) cut it about 6 inches long
Pump until the fluid is to the end of the tubing and push over the Brake Bleeder. Pump a few times then Open the bleeder and the entire system is Back filled right up to the MC. This is also how I change Brake Fluid! Clean out the master Cylinder with paper towels If not too big then clean it with a paper towel with Brake cleaner then fill the MC. WHILE Filling the Master Cylinder I slowly tighten the Bleeder while pumping and DONE! No bleeding Necessary because there is no air from the Bleed hole to the MC!
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frEEk
Administrator
ummm... yeah
Posts: 9660
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posted August 17, 2007 07:03 PM
hm, sounds like going the pressure route (mity-vac type thing) is the only option. gues si gotta pick one up (so much for this being a quick 30min job!)
yep, knew that part doug (i've bled more brakes than i care to remember), but appreciate the try. i will try to forgive you. perhaps i will spend a few sessions with my shrink to get over it 
interesting idea vince. i take it that has given you better results than "traditional" bleeding?
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thekaz
Needs a job
spell chequer is bustimicated
Posts: 2909
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posted August 17, 2007 08:53 PM
DAMMIT Freek if you were alittle closer and I wasnt goin south for the weekend 
Cuase I got all the gear
Chances are you just have a HUGE air pocket in the Caliper. Try bleeding the line before it enters the caliper at the banjo bolt. Then bleed the caliper while tapping the caliper with a soft faced hammer. Also prefill the caliper as much as possible.
or ya go and get a vaccum bleed system ...... i dont even bother trying with out mine anymore
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frEEk
Administrator
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posted August 17, 2007 09:13 PM
gonna pick one up tomorrow if i can.
the caliper is 100% empty (the halves were opened during the rebuild) and the line is empty too (gavity drained) so huge air pocket is certainly a reality here.
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frEEk
Administrator
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posted August 23, 2007 06:06 PM
well i'm going bananas. tried vacuum and it didnt do anything. i even tried pulling the line off the master cylinder to see what's going on inside, and there is NO movement of the fluid when i pump. WTF does that mean? huge air bubble somewhere i can only guess? in which case i imagine i either need way more pressure, or try vince's idea of filling backwards.
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shane661
Needs a life
Posts: 11494
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posted August 23, 2007 06:14 PM
You have to pump it and create a vacuum before you open the bleeder nipple.
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frEEk
Administrator
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Posts: 9660
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posted August 24, 2007 07:50 AM
did all that (am familiar with normal bleeding, that is to say, when the system isn't entirely empty)
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thekaz
Needs a job
spell chequer is bustimicated
Posts: 2909
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posted August 24, 2007 08:05 AM
if the master cylinder was also dry or completely emptied you may have to bleed that also....
take a short hose or the caliper end of the brake line and shove it into the reservoir then fill up the reservior and pump the thing a bizillion times until there are no air bubbles coming through the hose. Some master cyclinders don't take kindly to air trapped in them while other just push it through on the first try......
if you have the hand pump kind of vaccum bleeder it will NOT have enough power to bleed a master cylinder through the caliper and brake line. Even my compressed air assist one would have issues trying that......
Once you bleed the master cylinder then bleed the line at the caliper bolt then bleed the caliper.....
If the Master Cylinder does have air everything is useless until it is bleed properly 
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frEEk
Administrator
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Posts: 9660
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posted August 24, 2007 12:33 PM
thx for the tip kaz. unfortunately i'm jsut about convinced the master cylinder is busted, most likely plugged up. i pumped a good hundred times without so much as a single bubble. something is decidedly wrong and ive given up on figuring it out myself. will just have the dealer look at it next time i'm nearby. i cant waste no more time on this POS.
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VincentHill
Needs a life
Posts: 6520
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posted August 24, 2007 01:07 PM
To check the Master Cylinder only! Disconnect the Brake line! Put your finger over the Hole and with a paper towel under it slowly pull in the lever. and let the fluid squeeze out! The block the hole tightly ansd slowly release the lever. You should feel a Sucking on your finger. Once the vacuun is gone, Pull in the lever again slowly and let the fluid squeeze past. DO this several times until the end of the hole is full. Quickly attach the Brake line
Then with the line not tight, pull in the lever slowly. when all of the way in tighten the banjo Bolt and slowly release the lever. DO this a few times until you see no air. then you are ready to "Bleed the system" SOmetimes the brake lever does not come all of the way out and the MC Cannot get refilled!
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Made History @ Daytona and still one fast old man!!
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