Air continuously getting in brake line

[Toured]

I recently had trouble with my master cylinder, managed to buy one from Japan and replace it. Fully bled the brakes and all was well for about three weeks and then the brakes started to fade. Bled them again and found air in the front offside caliper. This occurred several times and I then replaced the caliper seals and pistons on both front calipers but still getting air in the front right caliper after a few weeks.

So I am only getting air at the front offside caliper. There is no air at any other caliper and best of all, servo is working fine and I am not loosing any brake fluid from anywhere, not even a little bit, every thing is dry externally!

So how am I ONLY getting air leaking INTO the front right caliper? Anyone have any ideas as I have run out.

 

[stellamon]

Maybe get someone to apply the brake while you look for a leak, should leak under pressure and then draw air in when released.
Possibly a brake pipe or line or calliper connection.

 

[Toured]

Tried that but not a drop from anywhere. Using a pressure bleed kit and nothing either. I even left the bleed kit on for a few hours and no drop in pressure. Nothings getting out but somehow air is getting in from somewhere and it is only on the one line, the other three are fine.

 

[stellamon]

Must be the calliper, did you check the seal was fitted the right way around

 

[Toured]

The seals for the calipers are square cut and not tapered as earlier hondas, so can go either way round.

 

[stellamon]

Found this:

place some red rubber grease over the valve threads ensures air doesn't get drawn in.

Think he means the bleed nipples.
Whole thread here:

Brake Bleeding - Mityvac

My new calipers and hoses are coming today, which I need to fit asap to cure my binding rear brake (changing both sides though). I'll probably be on my own when changing them so looking at alternative ways to bleed, has anyone used one of these, how did you find it...

typeaccord.co.uk

 

[Richard B]

Tried that but not a drop from anywhere. Using a pressure bleed kit and nothing either. I even left the bleed kit on for a few hours and no drop in pressure. Nothings getting out but somehow air is getting in from somewhere and it is only on the one line, the other three are fine.

It could be that fully extended under pressure the system seals OK, but in a retracted state the seal is sitting on a corroded / pitted area of the piston and letting in some air. The way to test that would be to remove the dust seal and and insert a spacer to limit piston travel. Then simulate driving conditions by cycling pressure on and off. Or you can do pull out the piston and visually inspect it.

 

[Channel Hopper]

I recently had trouble with my master cylinder, managed to buy one from Japan and replace it. Fully bled the brakes and all was well for about three weeks and then the brakes started to fade. Bled them again and found air in the front offside caliper. This occurred several times and I then replaced the caliper seals and pistons on both front calipers but still getting air in the front right caliper after a few weeks.

So I am only getting air at the front offside caliper. There is no air at any other caliper and best of all, servo is working fine and I am not loosing any brake fluid from anywhere, not even a little bit, every thing is dry externally!

So how am I ONLY getting air leaking INTO the front right caliper? Anyone have any ideas as I have run out.

Based on the last post, you could swop over pads to ensure the corrosion that might be present is behind a larger amount of material, or buy new pads if all are worn.
But I'm no expert, what mileage has the Accord done and are you in a corrosive - coastal area (or were earlier owners ) ?