Hydraulic brakes

[Levo-Lon]

Right.
Fix for this would be pressure up the brake and hold lever in, then undo the caliper bleed a fraction, this should release any trapped air +small amount of fluid
Keep hold of lever, Nip up the bleed with lever pulled in. Do not release!!
Cover with a rag to keep fluid off pads disc

 

[gazza81]

Thanks I'll give it a try tomorrow

 

[screenman]

Right.
Fix for this would be pressure up the brake and hold lever in, then undo the caliper bleed a fraction, this should release any trapped air +small amount of fluid
Keep hold of lever, Nip up the bleed with lever pulled in. Do not release!!
Cover with a rag to keep fluid off pads disc

Intrigued by this reply, why would the air only be at the nipple end? Now I have been bleeding brakes since 1969 and I have never come across this, the air is normally distributed all over the place. The only fix for air in the fluid is too change the fluid in my opinion.

 

[Levo-Lon]

Intrigued by this reply, why would the air only be at the nipple end? Now I have been bleeding brakes since 1969 and I have never come across this, the air is normally distributed all over the place. The only fix for air in the fluid is too change the fluid in my opinion.

Its more to do with shoving air, water out from the high point in a caliper.

This wont usually travel back up to the res.

Its called a pressure bleed, and simply clears the air under load.

Similar principle when bleeding brakes on a car, using the pedal to the floor and hold.
The pedal or lever is used to force everything out, if it is partially released with the bleed nipple open you draw air back in.

Done correctly with a bleed kit avoids this.
But sometimes air gets trapped ect so this should clear it.

 

[screenman]

I know how to bleed brakes, I also know that you will not clear air out of a system with one pump of a brake pedal, I of course know what happens when you release the brake pedal with the nipple open, my point is the air is all over the place and not at any one end, if it was why would it not be at the pump end? Now maybe, just maybe if you up ended the bike so that the bleed nipple was at the highest point and left it like that for a few days then the air might travel to that point, then open the nipple and one pump may help, I doubt it though.

 

[Levo-Lon]

I know how to bleed brakes, I also know that you will not clear air out of a system with one pump of a brake pedal, I of course know what happens when you release the brake pedal with the nipple open, my point is the air is all over the place and not at any one end, if it was why would it not be at the pump end? Now maybe, just maybe if you up ended the bike so that the bleed nipple was at the highest point and left it like that for a few days then the air might travel to that point, then open the nipple and one pump may help, I doubt it though.

Where did i say you can bleed a car with one pump of the pedal, this is about clearing a bubble in a caliper.
Also its about sorting problem the op is struggling with.

If the fluid is full of air it wont work.



I too know a lot about brakes, i used to work on them a lot in my garaged days and motorcycle days.

You ask a question then after being replied too go all condescending know it all.

You sort him out, as you know everything

 

[gazza81]

Right.
Fix for this would be pressure up the brake and hold lever in, then undo the caliper bleed a fraction, this should release any trapped air +small amount of fluid
Keep hold of lever, Nip up the bleed with lever pulled in. Do not release!!
Cover with a rag to keep fluid off pads disc

Theres actually a short clip on YouTube doing a full bleed using this method, it has hundreds of comments saying how it worked really well

I cant try it as i have no oil left, so ill get some in the week and will be trying it.

 

[si_c]

If you are getting new oil anyway just do a full bleed you could faff around for ages trying one fix or another and it only takes ten minutes to do the job properly.