Bleeding brakes with new braided lines........HELP ME!

chrisd · Apr 7, 2011

Alright fellas

Need some help bleedin my new lines...can't get any fluid down the lines at all. I've checked everything is tight and all washers are in place. When i try to bleed i can see air moving a drop of fluid in the bleed pipe but i've been bleeding for over 30 mins and cant get a drop thru the master cylinder. Ive tried bleedin that seperately too but nothing. Took the mc off and submerged it in the kitchen sink to check its got pressure and it does. any ideas???? need to get back on the road while the suns out!

wizbit · Apr 7, 2011

Try needing the small rubber connection pipe from the resivior to the master cylinder you might find it is air locked and you'll see bubbles jump up in the resivior.
Then try the m/c bleed nipple again.
Then go back to the calipers.
When priming the lines try the 'pump, close nipple, let go, open nipple, pump....' technique. Make sure you've got your bleed pipe submerged in a container with some fluid in to prevent air getting drawn back into the system.
Once you see fluid I just leave the nipple open and keep pumping and topping fluid up as required.

Hope this helps,

Dave

chrisd · Apr 7, 2011

Nice one Dave, im gonna give it one more go and if that doesnt work im gonna buy a vacum bleeder kit!! My other worry is that the rubber seal around the resovoir pipe has perished and is now leaking air. I'll give it go anyway.........ta

nikfubar1 · Apr 7, 2011

If you know anyone that works in a garage borrow a vacume brake bleeder. It sucks the fluid through rather than trying to pump it.

BRG · Apr 8, 2011

Hi chrisd,

Forget the 'traditional' bleed procedure (and vacuum bleeders for that matter), the only sure way to bleed the FRONT brake is to reverse bleed it (as it's easier to make bubbles go uphill than down!!).

There's a seminal article about this on the AF1forum http://www.apriliaforum.com/forums/showthread.php?t=15500, but to summarise:

Tools:

Cross-point screwdriver for reservoir cap
11mm (IIRC) ring spanner for nipple
Syringe to inject fluid - I use a 50ml one bought off fleabay - I could only get 10ml from a chemist and those are too small
Clear flexible plastic tube (10cm min - 10cm better) to connect syringe to nipple

Consumables

New/Fresh DOT4
Kitchen roll
Water mist spray (I use one intended for cleaning indoor plants)

Procedure:

Fit the clear plastic tube to the end of the syringe - you may need to heat the tube to get it over this
Remove the reservoir cap
Remove the nipple cap
Place a ring spanner over the nipple
Fill the syringe full of fresh new DOT4
Remove as much trapped air from the syringe as poss. (by squeezing it gently with the nozzle uppermost)
Force the tube on the end of the syringe over the nipple (it needs to be a fairly tight fit!)
Crack nipple and open - just enough to allow flow
Holding syringe above calliper and downward (nozzle at bottom) inject fluid into calliper (watching level rise in reservoir). Don't squeeze hard or you'll force fluid out of the nipple creating a mess!
Close the nut - don't swing on it, they only require a small torque - and remove the syringe/tube.

Now repeat for the other calliper.

I always get some seepage from the nipple. Have plenty of kitchen roll ready to mop up and if you get any fluid on paintwork, spray immediately with water then mop up.

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Bleeding brakes with new braided lines........HELP ME!

chrisd

wizbit

chrisd

nikfubar1

BRG

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