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Bleeding my bleeding clutch

Posted: Mon Apr 09, 2007 4:42 pm
by Fausto
Bollox!!! :smt013

Have been trying to replace the grimy fluid in my clutch (Aprilia Falco) and must have let air into the system so now it won't work.

Standard everything - no hose unions undone. It is sucking a little fluid each pump from the reservoir but not much. Have tried detatching the lever and reservoir from the bars to move them around and raise them higher in the hope of freeing any airlock but no good.

Any suggestions ?

:smt017 :smt017

Posted: Mon Apr 09, 2007 4:52 pm
by Aladinsaneuk

Posted: Mon Apr 09, 2007 5:00 pm
by Fausto
Hello Pete. Thanks for that. One or two new ideas I will try later.

I did wonder if I had been messing around for so long that I now have millions of small air bubbles throughout the system and if I let it stand overnight it may settle and a normal bleed would do the trick ?

Have a good ride?

As you can see I was otherwise engaged ! :smt009

Posted: Mon Apr 09, 2007 5:02 pm
by Aladinsaneuk
may do - but i doubt it - but worth a punt :)

a fresh mind tomorrow morning may help

the ride was lovely - and you know that snooty place by the station, opposite the anchor pub..... they ignored us and would not serve us etc

can't imagine why all the bikes were so noisy when we left.....

Posted: Tue Apr 10, 2007 6:37 pm
by Fausto
Got It !!

A mechanic friend suggested this and it worked.

Used an oil can with it's nozzle attached to clear flexible tube which in turn was attached to the bleed valve. The oil can has some brake fluid in it instead of oil.

Opened the bleed valve and pumped fluid up from the can and into the system in the opposite direction to normal bleeding. Back-bleeding.

Make sure the reservoir is kept at low level and covered as fluid will fill it as fresh fluid is pumped up from the bleed valve.

In theory air will more happily travel upwards and vent into the reservoir than downwards in the usual bleeding method.

Once lever has some 'bite' to it again I was able to revert to standard method bleeding and all was fine. Airlock removed.

WARNING - this can be messy and brake fluid can be damaging so protect shiny surfaces.

Posted: Tue Apr 10, 2007 6:54 pm
by Gio
Fausto wrote:Got It !!

A mechanic friend suggested this and it worked.

Used an oil can with it's nozzle attached to clear flexible tube which in turn was attached to the bleed valve. The oil can has some brake fluid in it instead of oil.

Opened the bleed valve and pumped fluid up from the can and into the system in the opposite direction to normal bleeding. Back-bleeding.

Make sure the reservoir is kept at low level and covered as fluid will fill it as fresh fluid is pumped up from the bleed valve.

In theory air will more happily travel upwards and vent into the reservoir than downwards in the usual bleeding method.

Once lever has some 'bite' to it again I was able to revert to standard method bleeding and all was fine. Airlock removed.

WARNING - this can be messy and brake fluid can be damaging so protect shiny surfaces.



I've used a vacuum pump to do this on my old Blackbird, I'll stick to the same on the Falco when I do it :smt001

Posted: Wed Apr 11, 2007 7:26 am
by XJR Jason
Use some silicon air hose from a fish tank (the rubbery stuff used on the air stones) about 1m worth.

Connect to the bleed nipple and suck the new fluid through. You can see how far up the tube the old fluid goes, disconnect and blow out before you start to swallow it!

Just remember to keep the reservoir topped up.


:smt001

Posted: Wed Apr 11, 2007 7:52 am
by Gio
XJR Jason wrote:Use some silicon air hose from a fish tank (the rubbery stuff used on the air stones) about 1m worth.

Connect to the bleed nipple and suck the new fluid through. You can see how far up the tube the old fluid goes, disconnect and blow out before you start to swallow it!

Just remember to keep the reservoir topped up.


:smt001


Can be a bit of a bugger if you smoke :smt010 :smt005

Posted: Wed Apr 11, 2007 10:59 am
by XJR Jason
Gio wrote:
XJR Jason wrote:Use some silicon air hose from a fish tank (the rubbery stuff used on the air stones) about 1m worth.

Connect to the bleed nipple and suck the new fluid through. You can see how far up the tube the old fluid goes, disconnect and blow out before you start to swallow it!

Just remember to keep the reservoir topped up.


:smt001


Can be a bit of a bugger if you smoke :smt010 :smt005

Bout time you gave up!

Posted: Wed Apr 11, 2007 4:00 pm
by Gio
XJR Jason wrote:
Gio wrote:
XJR Jason wrote:Use some silicon air hose from a fish tank (the rubbery stuff used on the air stones) about 1m worth.

Connect to the bleed nipple and suck the new fluid through. You can see how far up the tube the old fluid goes, disconnect and blow out before you start to swallow it!

Just remember to keep the reservoir topped up.


:smt001


Can be a bit of a bugger if you smoke :smt010 :smt005

Bout time you gave up!
Yes Sir ................................ :smt019 .......................................... :smt005

Thats given me an idea :smt115

Posted: Thu May 03, 2007 10:39 pm
by woody
XJR Jason wrote:Use some silicon air hose from a fish tank (the rubbery stuff used on the air stones) about 1m worth.

Connect to the bleed nipple and suck the new fluid through. You can see how far up the tube the old fluid goes, disconnect and blow out before you start to swallow it!

Just remember to keep the reservoir topped up.


:smt001


Better still, fill a syringe with fluid and 'back' bleed the brakes by connecting said bit of rubber O's to bleed nipple and syringe

Posted: Tue Jun 12, 2007 8:39 pm
by jam
Nip down to your local vets, they'll have some large syringes that you can buy for pennies, draw the old fluid out with it through the bleed niple, and dispose of it, then fill the syringe with clean fluid and then slowly pump it all the way up until the reseviour starts to fill. then you should be able to get some clutch action.
I use this method for all clutches and brakes, as it's quick and fairly clean. It usually takes only a couple of pumps of the lever once the res is full, and that is just to make sure that there's no air trapped in the caliper/slave cylinder from when you first connect the syringe and hose to it. I also leave the hose/syringe connected as I pump the lever, that way I don't spill fluid onto anything that may be damaged by it.

Posted: Sun Jun 23, 2013 9:24 pm
by zoidberg
jam wrote:Nip down to your local vets, they'll have some large syringes that you can buy for pennies, draw the old fluid out with it through the bleed niple, and dispose of it, then fill the syringe with clean fluid and then slowly pump it all the way up until the reseviour starts to fill. then you should be able to get some clutch action.
I use this method for all clutches and brakes, as it's quick and fairly clean. It usually takes only a couple of pumps of the lever once the res is full, and that is just to make sure that there's no air trapped in the caliper/slave cylinder from when you first connect the syringe and hose to it. I also leave the hose/syringe connected as I pump the lever, that way I don't spill fluid onto anything that may be damaged by it.
Going to try this one

Posted: Mon Jun 24, 2013 5:41 pm
by fatboy
The guys who do all our fleet maintenance always use this method on hydraulic or air over hydraulic clutch slave cylinders.
As has been said, air prefers to travel upward, fluid downward so it makes sense to use gravity and physics to your advantage.
Recently could not get Falc rear caliper to bleed up, trying every method suggested, so
removed caliper,suspended with bleed point lowest, held pedal down with stick so ports remained open in master cylinder, 24 hours later and gravity is my freind rather than enemy