I mount a 140 brake booster and master cylinder identical to the type found on the 1969-1970 euro amazons. Until recently it's been a largely trouble-free setup, looking stock and being 100% volvo.

I recently upgraded to stainless steel flex hoses and replaced the complex self-adjusting rear brake shoe/drum/plate assembly with a *much* simpler 1967 style. I did this in two stages.

Part way through the "job" (just the front flex lines), I found that my braking power was gone. The car slowly glided to a halt and scared the heck out of me. I re-bled my lines with a pressure bleeder and found no improvement. I removed my Master cylinder and found some brake fluid on the back, so I figure that I had blown the old seals. I had suspected old MC would be a problem for a while now...

I ordered a replacement master cylinder and installed it over the weekend - along with the stainless rear flex line and replacement drums/shoes/plates. I also took the opportunity to re-pack the rear axle bearings.

The brakes did not improve much, but after a careful bleed sequence (working farthest to closest and tapping the lines and calipers along the way to knock any air bubbles loose) the car does stop and hold properly now.

The main problem now is that the pedal travels very far before the front brakes "grab." I would have assumed another bad MC, or bad flex lines, except that the new MC passes the "high-and-hard test" (where you install plugs in the MC brake fittings and give the pedal a pump). The new MC is rock-solid. If it is isolated from the rest of the system.

I also pulled and swapped in the new (as of last year) rubber flex lines I had, and I blew-out the stainless lines. Reinstalling the rubber flex lines did nothing and both front lines blew clear with no evidence of clogs.

My brake actuator rod is already near maximum adjustment and I don't see why I would have to adjust it for something as simple as new flex lines and a new MC.

I've bleed this baby several times and I am quite confident there is no air. The rear brakes appear to work just fine, but the front seems to cause the excessive travel.

I have tried swapping the front and rear lines on the MC and found not change. I've also checked every fitting and junction for leaks and have found none.

Unless there is a clog in the hard lines that is invisible when bleeding, the calipers themselves are the only remaining suspect. Since I have the braided stainless lines, I cannot simply clamp the rubber lines off to try and isolate the problem.

All I can think of trying now is to pull and replace the forward hardlines and/or swap the calipers for a rebuilt set. Both are a pain and would require re-bleeding the whole system again...

Anyone have an idea of what I am overlooking here?