AP Princess Calipers air locks

[braveheart 3]

Hi everyone am running out of things to try and any advice would be appreciated.
Updated front brakes on my TVR wedge to AP Princess 4 pot calipers and am having real issues with pedal and air.
Pressure bled with one man kit for half a day and no visible air after going round and round they have 4 bleed nipples per side !
On the road pedal varying and comes up with pumping but not confidence inspiring or safe.
Weird thing also is when reversing after a run the pedal drops even more when backing up ?
I also need to add I changed the master cylinder also after it failed on a previous run so really not sure where the air is.
Am I missing something here or do I now go to pressure bleeder at a higher pressure or go back to two man method?
To be honest should have just rebuilt the standard calipers as these feel worse on the road and don't seem worth it !
All the best
Brave heart

[stevieturbo]

braveheart 3 said:

Hi everyone am running out of things to try and any advice would be appreciated.
Updated front brakes on my TVR wedge to AP Princess 4 pot calipers and am having real issues with pedal and air.
Pressure bled with one man kit for half a day and no visible air after going round and round they have 4 bleed nipples per side !
On the road pedal varying and comes up with pumping but not confidence inspiring or safe.
Weird thing also is when reversing after a run the pedal drops even more when backing up ?
I also need to add I changed the master cylinder also after it failed on a previous run so really not sure where the air is.
Am I missing something here or do I now go to pressure bleeder at a higher pressure or go back to two man method?
To be honest should have just rebuilt the standard calipers as these feel worse on the road and don't seem worth it !
All the best
Brave heart

Sure you didnt fit them upside down ? lol


Even just opening the nipples and letting gravity bleed will work in most cars. There should rarely be a need for either pressure or vacuum bleeding unless the system was completely dry or it has stupid things like ABS etc

[braveheart 3]

Thanks Stevie
Will try that
Braveheart

[The Wookie]

If you've fitted a new master cylinder then chances are that's where the air is as they are typically a pain to bleed. Alternatively if the pedal is sinking after bite then you may have a slight leak somewhere that's drawing in air off brakes.

[stevieturbo]

As an example...

http://www.ebay.co.uk/itm/Medical-syringes-injecti...

Large syringe and clear bit of tube.

Means you can easily move fluid both directions in the system, and it's easy to see if any air bubbles are coming with it via the clear tube

Or even larger 160ml

http://www.ebay.co.uk/itm/Large-Big-Huge-50ml-100m...

100ml is plenty for just bleeding, I guess if the system was dry the larger could be handier to either pull fluid from the master, or reverse bleed by pushing it from the caliper into the system

[braveheart 3]

Many thanks Gents
Regards
Braveheart