Bleeding dual-front brakes

[GrumpyGuts]

After rebuilding both my front calipers and replacing the sealing washers, I'm having a spot of bother getting fluid down the lines.

What is the procedure of bleeding front brakes with two calipers?

I put in the fluid into the master cylinder, pumped a few times and air bubbles started popping out from the valve. Good, then I started to open the nipple whilst pumping the brake pedal (same way I bled a single line) but after about 10 minutes turning this stupid nipple like a twat, nothing and I mean NOTHING is flowing down the clear tube.

Any advice on this? What caliper to start on etc etc

EDIT: I have also rebuilt the master cylinder
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My Bikes: Lifan Beat 125cc '11 -> Suzuki B120P '76 -> Suzuki EN 125-2A '08 -> Honda CG 125 '04 -> Honda CB600F Hornet '98 -> Kawasaki ZZR 600 '99 -> Kawasaki GPZ 500S '95 (Current)
Theory test passed - 09/02/2012 >>>> Module 1 passed 24/07/2012 >>>> Module 2 passed 24/10/2012

[P.]

Do you have a line per caliper or does it feed to the right and link to the left going across the mudguard?

Mine was the latter, I did the further one first. Keeping the closest bleed nipple closed and opening the further one.

[chris-red]

[stinkwheel]

Try bleeding it at the master cylinder banjo bolt first. They can airlock here and you get absolutely nowhere.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Bezzer]

[moppy]

Get a big ass syringe, fill it up with brake fluid and with a little bit of tube, connect it to the bleed nipple. Open bleed nipple and squeeeeeeze slowly but surely. Too hard and the seals may be blown out.

Filling from the bottom up is the way to go.

Edit: Oh and you are doing "Open nipple, pull lever, close nipple, release lever" yes? Sorry if that is a bit basic, but never know...

I find chanting open pull close release like a mantra when I'm bleeding brakes helps me from releasing lever while nipples still open. I do sound a little crazy though.

[stinkwheel]

If it's any help (not sure if it is or not) I always give the lever three pumps and crack the bleed nipple only during the third pump.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[MarkJ]

[Fizzer Thou]

[GrumpyGuts]

Well I have tried with no luck.

I disconnected the banjo bolt from the MS and no fluid flowed out (dunno if it is meant to be like that?) Tried bleeding it from that bolt (i.e. manually bleed it like I would a bleed nipple) but the fluid level stays exactly the fucking same!

EDIT: Really should go to bed - there's air in the master cylinder so I will try and prime it. PITA

EDIT 2: Lol, how do you prime it? Finger over the hole as such, but what do you exactly do? I'm so knackered I'm leaving it to tomorrow morning
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My Bikes: Lifan Beat 125cc '11 -> Suzuki B120P '76 -> Suzuki EN 125-2A '08 -> Honda CG 125 '04 -> Honda CB600F Hornet '98 -> Kawasaki ZZR 600 '99 -> Kawasaki GPZ 500S '95 (Current)
Theory test passed - 09/02/2012 >>>> Module 1 passed 24/07/2012 >>>> Module 2 passed 24/10/2012

[stinkwheel]

[Fizzer Thou]

There are two holes for fluid transfer in the master cylinder.Check to make sure that the smallest is not blocked.

I use a small strand of wire to check any ones that I am working on.It does not take much for that small hole to get blocked.
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Just talk bikes.What else is there?

Always have a 'Plan B'

[GrumpyGuts]

That's weird because when I pump the lever with my finger over the hole, I can feel air pushing against my finger and when I tried to bleed it normally, air bubbles floated out that little hole you see inside the reservoir. You also see like a black cloud forming out of this little hole when I'm pumping it with my finger over the hole
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My Bikes: Lifan Beat 125cc '11 -> Suzuki B120P '76 -> Suzuki EN 125-2A '08 -> Honda CG 125 '04 -> Honda CB600F Hornet '98 -> Kawasaki ZZR 600 '99 -> Kawasaki GPZ 500S '95 (Current)
Theory test passed - 09/02/2012 >>>> Module 1 passed 24/07/2012 >>>> Module 2 passed 24/10/2012

[cimbian]

Try as suggested by bleeding from the nipple upwards.
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22PlusY
Current: Moto Guzzi 1100 Breva. Previous: Honda XL650V TransAlp
Bearded, Balding, Born again Buddhist Biker

[GrumpyGuts]

It won't bleed from the nipple as nothing is getting through the master cylinder at all. When I first filled it with brake fluid, there were air bubbles coming up, but that was the last time I saw any.

Now, there is just a black cloud coming back into the reservoir which means the fluid is being pushed back in.

I removed the banjo bolt and put my finger over the whole and pumped...I could feel air pushing against my finger, but what do I do from there?

Sorry for all the questions but I'm pretty desperate!
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My Bikes: Lifan Beat 125cc '11 -> Suzuki B120P '76 -> Suzuki EN 125-2A '08 -> Honda CG 125 '04 -> Honda CB600F Hornet '98 -> Kawasaki ZZR 600 '99 -> Kawasaki GPZ 500S '95 (Current)
Theory test passed - 09/02/2012 >>>> Module 1 passed 24/07/2012 >>>> Module 2 passed 24/10/2012

[moppy]

Master reservoir rebuild? Kit is only £30 from Wemoto and step by step instructions here.

Or just take it apart, clean and see if it all looks like it should then put it back together using that guide?

Don't really have any real advice I'm afraid

Edit: Fucking hell, considering what you're actually getting, £30 is a bit steep isn't it...

[GrumpyGuts]

I have already rebuilt the master cylinder - they say you then need to prime the master cylinder (MS actually pumped before I took it apart!) but I don't know where to go from there
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My Bikes: Lifan Beat 125cc '11 -> Suzuki B120P '76 -> Suzuki EN 125-2A '08 -> Honda CG 125 '04 -> Honda CB600F Hornet '98 -> Kawasaki ZZR 600 '99 -> Kawasaki GPZ 500S '95 (Current)
Theory test passed - 09/02/2012 >>>> Module 1 passed 24/07/2012 >>>> Module 2 passed 24/10/2012

[Fizzer Thou]

Could it be that you got the spring around the wrong way?

Or you caught the seal on the piston and not pushing the fluid through by transfer?Might be an idea to start there or borrow a good master cylinder from somewhere just to isolate that this is where the problem is.

Pity that you do not live closer
____________________
Just talk bikes.What else is there?

Always have a 'Plan B'

[GrumpyGuts]

I installed it all correct according to Monsieur Haynes.

I've got somewhere though. Doing that finger over the hole thing, I can manage to spay fluid all over my clocks (only light sprays though) and the pumping action is good as I can feel the air pushing against my finger, but not enough for all the fluid to start pouring out like it should. I would note that before rebuilding the MC it worked before!

Fuck that sounded too dirty
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My Bikes: Lifan Beat 125cc '11 -> Suzuki B120P '76 -> Suzuki EN 125-2A '08 -> Honda CG 125 '04 -> Honda CB600F Hornet '98 -> Kawasaki ZZR 600 '99 -> Kawasaki GPZ 500S '95 (Current)
Theory test passed - 09/02/2012 >>>> Module 1 passed 24/07/2012 >>>> Module 2 passed 24/10/2012

[kramdra]

[Kickstart]

[Xenocide]

Sometimes just holding the lever to the bar and giving the mc a couple of taps with a spanner is all it takes to get it moving.

You need to make a vaccum at the caliper end so that fluid is sucked down. You can make a brake bleeder out of an old animal feed bucket and a hoover :p.
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KTM LC4 400 | Honda VTR1000

[Dave-the-rave]

I fitted steel brake hoses today. I just filled the reservoir, put clear tube on the bleed nipple, open nipple, squeeze lever and suck the fluid down. When it's in the tube close nipple (without getting it in your mouth). Repeat on other side.
Keep checking fluid level throughout.

Finnish by bleeding normally. Simple, quick, hassle free.

Disclaimer for children and mentally challenged....

Brake fluid in the gob, lungs or stomach isn't clever so I'm not advising this method just because I do it.

[GrumpyGuts]

[kramdra]

Cant understand why people do shit the most difficult way.
100ml syringe will hold enough to completely fill a dual front system, twice (useful for pushing all the crap out of MC) If you do it in one push action, no air can get in. Perfect.

Today had to drain a petrol tank, but there was always some water left, this got it all out. Then I wanted to remove water that had seperated at bottom of fuel, syringe again.

https://www.ebay.co.uk/sch/i.html?_from=R40&_nkw=100ml%20syringe&_sop=15

About 3 quid each, bloody usefull tool. Going to order a new one, since I used it on fuel and I got brakes on other bike soon.