What i meant was when you bleed it with a bleeding system/device usually the clear pipe that you put over the nipple can let air in. I like to have some1 pump the pedal, hold it down while i open the nipple and close it, then pump again.

its best to bleed by opening and closing nipple but clear plastic pipe does show better air in fluid

Yes it would show air in the fluid, but how would you tell if its getting in where the clear pipe slides over the nipple?

Is there air coming from all 4 callipers?

Im no expert by any means. And i dont mean to state the obvious here.

But could it be possible that air is getting in, but fluid not leaking out. Like at a union. I would of thought it only needs to be abit. Im a novice, but i must admit i have had my fair share of brake problems.

Check every single union front to rear again maybe?

My second concern is that if there was any power steering fluid still in the lines while the new calipers were bolted on, any pas fluid present in that system will have pushed into the new calipers? Potentially ruining the fluid seal and letting air in.

By all means dismiss my opinion, as im no mechanic and self taught and the help on here. But thats just my thoughts of it. Youve tried everything else by the sounds of it.

Hope it helps

Thanks so much for all the advise.

When I first stripped the system after I put the PAS fluid in, I gravity bled all the lines as soon as the new master cylinder was installed. I did this for quite a while, so I really hope that I got all the contamination out of the metal lines.
Then I installed the other brake lines and calipers.

I do agree that there is the possibility of air seeping in without fluid leaking out. this evening I will go and check every union, surely if air is seeping in the union will be at least a little moist?

really amazing how something as simple as this brake system can give me so much problems.
It really has to be something very simple.

Must be so frustrating too - surely must be something really silly

Station House said:

Must be so frustrating too - surely must be something really silly

Click to expand...

Very frustrating.

But, I am still driving her.
She will still stop, its just that sometimes the peal is hard and other times its soft.

Going on another big road trip on the 25th of the month, fixed or not.

Brakes are a luxury