Brakes

[dwc]

Afternoon,
I have just rebuilt the front brakes on my Vee-Strom and I'm experiencing some trouble bleeding them. May be somebody will be able to help?

I refitted them today, after the pistons had been removed and cleaned and new seals fitted, All is shiny and new.
I've tried bleeding the system in the conventional way, but although the brake fluid is running clear with no air bubbles present the system has no pressure. I'm of the opinion that there may be air trapped somewhere, possibly in the caliper. Despite attempts to dislodge the pocket of air by tapping with a rubber mallet and shaking the caliper I have had no success. At this point I've resorted to putting it on the stand and cable tying the brake lever open in the hope that the system will purge itself overnight.

Any further suggestions would be appreciated, and is this a common problem. I've never experienced it before!!!

Regards DWC

[Stenno]

Did you just rebuild the callipers or did you touch the brake handle and reservoir?

And when you bled them was the brake handle used to pump it through OK? Was the reservoir kept full?

[Strommer]

I find the same whenever I do mine.  Only way around it seems to be to not fit them so that you can wiggle them around, then do the handlebar tied back thing.  Usually takes me two weeks.....

 

[greywolf]

There can be an air bubble caught where the brake lines connect to the master cylinder. There are replacement banjo bolts available that have bleeders on the end. You can also crack the bolts open slightly to allow air out. It will leak some fluid which is nasty stuff so be prepared with paper towels and cleaner.

[dwc]

Hi,
thanks for swift response.

I haven't touched the master cylinder. Only to pump fluid to the calipers.

Greywolfs suggestions seems promising I will give that a try and leave overnight.

Regards DWC

[mjc506]

at risk of teaching you to suck eggs, when you say 'haven't touched the master cylinder', you have opened the top and filled it with fluid during bleeding, right?

[dwc]

Hmmmmmmmm,

Those eggs take some sucking!!!!!!

Just cracked the banjo bolt on the master cylinder hopefully that will do the trick. I'm reaching frustration point so will leave well alone until tomorrow.

Thanks for the suggestions all are welcome even those of the egg persuasionhttp:

[Keith Cross]

I normally use a syringe to help bleed brakes now.  I fill up the reservoir and attach a large syringe tot eh bleed nipple wit a short length of tubing.  Crack the bleed nipple open and suck the fluid out of the system masking sure the res does not run out of fluid.
Once you have got the air out, keeping the syringe connected you can just pump the system to get the last of it out.

Keith C

[Locky]

I use a Mityvac and it bleeds them very easily first time , a syringe does the same job .

[Keith Cross]

I use a Mityvac and it bleeds them very easily first time , a syringe does the same job .

And is lots cheaper

In fact for free if you have a friendly drug addict

Keith C

[Strommer]

Problem is when you have to remove the seals.  I've not found a way to prevent air getting in.

[dwc]

Folks,

A hearty thank you from me.

With a combination of using all suggestions , except anything vaguely eggy,I have managed to expel the problem and now have functioning brakes. Back on the road tomorrow.

Regards DWC

[mjc506]

good stuff