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Bleeding brakes...
 

[Closed] Bleeding brakes...

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[#4387301]

I have some original Hope Minis (pre-mono). The rear one was a bit soft - I needed to pull the lever a few times before a ride, and then it would work, but pull back further than the front. So I assumed a bleed would be helpful. Once I'd removed the reservoir cap, oil started dribbling out as soon as I opened the bleed nipple*. So I've run some oil through it, and topped up the reservoir. Now it doesn't work at all.

*Which I think means that the seals in the lever are shot. Or could it be something else?


 
Posted : 21/09/2012 9:51 pm
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bump for the morning crowd. Or maybe no-one knows...


 
Posted : 22/09/2012 7:02 am
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You could still have air in the system, how are you bleeding it? Also quite possible that the M/C seals are gone(or the bore scored) on a brake of that age, and a high possibility that the caliper needs a strip/clean/lube too.


 
Posted : 22/09/2012 8:05 am
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Id try bleeding again before going into major surgery.

The other day I bled a set of Ex3's with the same result, second bleed glug glug glug out came a load of air.

Do you need to reset the reach adjuster? Some brakes it says in the bleed instructions to wind it all the way in/out (cant remember which way) or you cant bleed it properly.


 
Posted : 22/09/2012 8:14 am
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OK, I'll have another go later. It is annoying as this was a working, if not perfectly, brake and now it is useless. Probably my numptiness!

I'm bleeding them by:
1. Removing the reservior cap and its seal
2. Opening the bleed nipple a 1/4 turn
3. Squeezing the lever

...but oil drips out freely at #2 when (I think) it shouldn't happen until #3


 
Posted : 22/09/2012 10:31 am
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you are meant to put some tubing on the bleed nipple to prevent air entering the system


 
Posted : 22/09/2012 10:34 am
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squeeze the lever before you open the nipple, close nipple before realeasing the lever and repeat a lot untill you get no more air coming out with the fluid.


 
Posted : 22/09/2012 10:35 am
 sbob
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Is [url= http://forums.mtbr.com/brake-time/hope-mini-disc-brake-overhaul-238831.html ]this[/url] of any use?

Although it seems arse about face to me; the brakes I'm used to one would bleed the system from the caliper with a syringe, forcing any air upwards (the way it wants to go anyway) and out of the reservoir in the lever.
If I used your method I too would get fluid pissing out of the caliper as without the reservoir seal in place you effectively have a bit of tube with two open ends: air can enter the top of the tube (at the lever) so fluid can just drain out of the bottom (the caliper).
Unortunately I'm not familiar with the Hopes.

ETA: [url= http://a.blip.tv/scripts/flash/stratos.swf#file=http%3A%2F%2Fblip.tv%2Frss%2Fflash%2F1576358&showplayerpath=http%3A%2F%2Fa.blip.tv%2Fscripts%2Fflash%2Fstratos.swf&feedurl=http%3A%2F%2Fmtbcut.blip.tv%2Frss%2Fflash&brandname=Hope&brandlink=http%3A%2F%2Fwww.hopetech.com&enablejs=true&showguidebutton=false&backcolor=0x000000&frontcolor=0x00FF33&referrer=http%253A%252F%252Fwww.hopetech.com%252Fpage.aspx%253FitemID%253DSPG219&source=3 ]Hope's video.[/url]

Dunno if that applies to your brakes.


 
Posted : 22/09/2012 10:59 am
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Thanks all. Tried again as per Hope's video, and it seems fine now.

Next up, bleeding some Maguras. Now they ARE a syringe at the caliper job, I believe.


 
Posted : 23/09/2012 6:16 pm
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Air naturally goes up, and gathers in the high points... So the best and easiest way to bleed any brake is from the bottom up. You can bleed Hope from the top down of course but considering a couple of syringes and a bit of hose cost about £2 I don't quite get why you would.

Hope are usually lovely to bleed though, they seem to have few airtraps etc unlike some.


 
Posted : 23/09/2012 6:31 pm
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Magura's are usually a 2 syringe method, depending on which model and year.

Take a look here for our range fo Magura bleed kits:

http://www.epicbleedsolutions.com/products/bleed-kits/magura/


 
Posted : 24/09/2012 1:51 pm
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The Hope vid is great and same principle works for many other brands. They miss this bit though


squeeze the lever before you open the nipple, close nipple before realeasing the lever
which is important to make sure you don't introduce any air thought the bleed nipple


 
Posted : 24/09/2012 2:07 pm
 MSP
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Don't forget that magura use mineral oil and not dot fluid.


 
Posted : 24/09/2012 2:13 pm