Basing my observations on the ATE setup on my 06.

I just wanted to say there is NO way for the seals to flip/invert if the brake pedal is pushed to the floor.

The ATE setup uses a two part piston which comprises anodised alloy tubes with springs on the ends, no seals whatsoever.

It is the master cylinder which houses the 3 or 4 seals.

Only if you filled the reservoir with grit and water could you expect wear on the piston but the seals would be worn by then anyway.

Just a heads up as I'm sick of hearing the old warning perpetuating.

I can see if you had an old style steel piston with seal(s) attached (think sink plunger) and the master cylinder was simply a smooth cast iron bore it ran in that cobbled seals could happen.

In my ATE system I can imagine seal weep but not seal flip/invertion, there simply isn't the clearance.

Basing my observations on the ATE setup on my 06.

I just wanted to say there is NO way for the seals to flip/invert if the brake pedal is pushed to the floor.

The ATE setup uses a two part piston which comprises anodised alloy tubes with springs on the ends, no seals whatsoever.

It is the master cylinder which houses the 3 or 4 seals.

Only if you filled the reservoir with grit and water could you expect wear on the piston but the seals would be worn by then anyway.

Just a heads up as I'm sick of hearing the old warning perpetuating.

I can see if you had an old style steel piston with seal(s) attached (think sink plunger) and the master cylinder was simply a smooth cast iron bore it ran in that cobbled seals could happen.

In my ATE system I can imagine seal weep but not seal flip/invertion, there simply isn't the clearance.

Are you saying, Mac, that when I used the whole travel on my 55 plate to push my piston out a little (to see if seized) I will not have caused any damage to my master cylinder seal(s)??????

 

I read (afterwards) that this can cause seal damage when pushing over the little / unused part of the piston.

 

Cheers.

Edited 10 August, 20169 yr by Tilt

I've stripped two ATE master cylinders of 06/07 vintage and found no discernable wear on the anodised piston(s) so full travel will not cause any seal damage.

Assuming of course that the reservoir was only filled with clean fresh fluid as and when required.

There is a fine gauze filter in it anyway but it's possible that really poor fluid with fine particulates and water content could get past and cause frictional wear on the piston(s)/seals, creating a wear lip and hence the potential for damage when pushed past the seals.

Honestly though, I expect you'd have a gash brake pedal by then anyway and fluid leaking past and into the vacuum servo necessitating frequent top ups.

I've one for sale if you want... PM me.