Hi Guys,
 
Here is the problem I have with my MK1 V6 project.
I have replaced the booster (reco), master cylinder (new aftermarket), rear wheel cylinders, flex lines and had the calipers reconditioned. I have bled the brakes and have a realy good pedal, it;s not spongy all the air is out of the system (bled the brakes multiple times). With the car jacked up, the rear and front wheel both stop when the brakes are applied. The rear brakes have been adjusted right up, almost binding.
 
When I start the engine and put my foot on the brake, the pedal almost goes to the floor, the brakes still work ok but the pedal is about half its original height.
 
Any ideas??
 
Cheers Mark

Did you bleed the master cylinder on the bench?  Pedal to the floor means the master cyl is bypassing due to a damaged seal, or it has air in it, but if it eventually firms up but lower like you say then it has air in it.  The master cyl should always be bled on the bench first.

When you bled the system how did you do it?  If you pushed the pedal all the way to the floor this may have damaged your seals and explain the problems you are having.
 
You should only push the pedal half way and never to the floor  
 
Cheers
 
Matt

The V6 capris have a high point in the brake line near the left corner of the engine bay.  This gets an air lock.  you need to jack the right side up so the master cylinder is the highest point.  I have also found that drip bleeding the bleed nipples first helps.  Also you need 2 people to bleed, have one depress the pedal and the other tighten the nipple at the depressed point, then let the pedal up with the nipple closed, doing one stoke at a time,  not 6 pumps then pushing the pedal while opening the nipple (i have seen a few people use this method, i reckon it makes the fluid foam)  

Oh the other thing, check the free play with the pedal.  The capri has an adjuster between the booster and master cyl, if this is wound out to much the brakes will lock on

............AND if this adjuster between Booster & Master is wound too far in, will cause the pedal to "floor" or almost "floor" depending on the amount of incorrect adjustment, or lack thereof.
I doubt there's still air trapped in any of the lines, as you say your pedal is "high" and effective and brakes are normal,  until you start the engine and the Booster comes in.
It certainly wouldn't hurt to lift right side as GTV6 says, and bleed again to ensure "Murphy" doesn't get his way !
While youre checking the adjuster tween Master & Booster, don't forget to "Bench-Bleed" Master. An experienced
person can do this while it's still bolted to the Booster with lines "cracked" and lots of rag to catch the ullage.