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Old 05-01-2013, 05:47 PM   #16
ontic
 
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one thing that works well for me also when bottom up bleeding, when it seems there are stubborn air bubbles, is to crack and bleed at every other possible juction- ie line to caliper, line to master cylinder, etc. You need very well placed wrags and care to do this of course.
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Old 05-02-2013, 12:14 PM   #17
RobboJ OP
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After leaving the lever tied half way back the brake feels really good, with good pressure and positive feedback.
Only thing is now it seems that the pads are rubbing the disc when the lever is released, braking is good though.

Perhaps a good ride will sort this out? Unless there is another trick? I was only in the garage for 5 mins otherwise I would have checked the callippers out
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Old 05-02-2013, 04:42 PM   #18
Kai Ju
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Re the brakes rubbing. Did you adjust the calipers to the rotors ? The inside pad is supposed to be parallel to the rotor, if it isn't make it so.
Draw six lines across the inside face of the rotor, 60 degrees apart. Spin the wheel with light brake pressure applied. See where the marks are rubbed off, should be even across the width of the rotor. If it isn't, use the eccentric bolt to adjust the calipers. Recheck and ride.
One method I found to work well, as have some others here, is to get it close and then apply pressure to the lever and rotate the bolt till it stops, rotate the other way until it stops, then split the difference.

Kai Ju screwed with this post 05-02-2013 at 08:11 PM
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Old 05-02-2013, 06:19 PM   #19
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Quote:
Originally Posted by Kai Ju View Post
One method I found to work well, as have some others here, is to get it close and then apply pressure to the lever and rotate the bolt till it stops, rotate the other way until it stops, then split the difference.
+ 1 !!!
I think we had a thread covering this method - so fast and easy. I will try to find it and post the link.
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Old 05-02-2013, 07:13 PM   #20
DaveBall
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Ate brakes can be a pain if you don't line them up properly. The method Kai Ju describes is the preferred and easiest method to get them lined up.

Sounds like you are getting them all sorted out. Next thing is to get on and ride it like you stole it.
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Old 05-03-2013, 07:14 AM   #21
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Newbie questions on bottom up bleeding

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Originally Posted by DaveBall View Post
Now class, please take notes on the above as it will be on the test.
I'm missing something. How do I make sure that both brakes (twin front) are properly bled using the bottom up method?

If I want to replace all the fluid would I drain all the old out first (through the bleeders)?

Thanks,
Steve
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Old 05-03-2013, 07:24 AM   #22
craydds
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If I want to replace all the fluid would I drain all the old out first (through the bleeders)?
One could drain out the old brake fluid through the caliper bleeder valves, but that would introduce MORE air into the entire system. DaveBall's method flushes out the old brake fluid from the bottom - up through the bleeders and out the master cylinder. This requires drawing fluid OUT of the MC reservoir - pump fluid up through each bleeder (both calipers, one side at a time), "suck" fluid out of the MC reservoir with a syringe, pump more into the system until it is clear and clean. Clear as mud?
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Old 05-03-2013, 08:18 AM   #23
Kai Ju
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Quote:
Originally Posted by GeekX2 View Post
If I want to replace all the fluid would I drain all the old out first (through the bleeders)?

Thanks,
Steve
Go to the pharmacy and get a nasal aspirator. It works great to suck most of the brake fluid out of the master cylinder. Refill with fresh fluid.
This way your not forcing old fluid through the system.
Attach a hose to the bleed nipple that will reach all the way to bottom of a clear container. Mason jar will work.
Fill the container enough to cover the end of the hose. Open the bleed nipple and pump the brake fluid through until you get clear, fresh fluid. Repeat with the other side. Make the hose long enough so that you can have an upward loop. This will prevent air from going back into the caliper and lets you see if there was any more air to start with.
Make sure you keep an eye on the master cylinder reservoir fluid level, because you don't ever want to hear that sickening sucking sound of air being drawn into the master cylinder.
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Old 05-03-2013, 08:40 AM   #24
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Think I've got it now

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Originally Posted by craydds View Post
"suck" fluid out of the MC reservoir with a syringe,
I missed step 8 in Dave's original listing. Think I've got it now. Thanks.
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Old 05-04-2013, 09:33 AM   #25
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So I tried every method described above and I have had no success. Every time I bleed it I still only get a bite halfway down and I can pull the lever all the way to the bar with a bit of a squeeze.
I usually sent 300-400ml through the system every time, with every method - on my own and with friends helping.

I have:
Twin ATE brakes
Stainless Goodridge hoses
Under tank alloy splitter
Magura 14mm handlebar M/C

So far I have changed a bleed nipple as I thought it to be suspect, also had the M/C apart and it looked Ok.
Next step is tank off and inspect the splitter, I can't think what else could be wrong? Pads are virtually touching the disk when home, and bite on the disk when the brake lever is depressed half way, it almost seems like the lever has free playbut both the plunger and lever looked fine, I had the whole assembly apart for inspection.

Any ideas?
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Old 05-04-2013, 10:17 AM   #26
Stan_R80/7
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I would screw a plug into the handlebar MC and check to see if that stops the lever from going to the handlebar. Plugging the MC is an easy and effective way to bleed a MC. If the MC checks out as good (i.e. the lever firms up), then there is still air (somewhere) in one or both caliper(s). Good luck!
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Old 05-04-2013, 06:38 PM   #27
Kai Ju
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Ok, let's start at the top, literally.
Wrap a rag around the brake line just below the banjo bolt.
Squeeze the brake lever and carefully loosen the banjo bolt.
Hopefully you'll hear/see bubbles coming from the crush gasket area.
Repeat until there is no more air coming out.
Proceed to bleed as normal.
Sometimes air can get trapped in that area and refuses to go anywhere during the bleeding process.

Mind you, I've converted my bike to dual disc using the stock, undertank, 14mm master and lever feel appears "soft".
I can pull the lever almost all the way to the bar but that's likely because of the cable arrangement.
The point I'm making is that the small piston master cylinder will not feel like the larger piston master cylinder but the brakes work quite well nonetheless.
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Old 05-09-2013, 09:38 AM   #28
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Checked and bled the M/C
Bled R/H calliper
Bled L/H calliper

No change

Bled L/H calliper some more... Hey presto! Magic brake
Guess there was a tricky bit of air in the hose or calliper somewhere?

Anyway brakes work a treat, now to bed them in
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Old 05-10-2013, 09:30 AM   #29
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Quote:
Originally Posted by Kai Ju View Post
One method I found to work well, as have some others here, is to get it close and then apply pressure to the lever and rotate the bolt till it stops, rotate the other way until it stops, then split the difference.
Oh yes, that is the way to get them lined up perfecto. Essential for the ATE design.

Little bubbles can hang inside the system. Use a small tool and tap tap tap the lines and calipers to break them loose, then they will flow out.
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