Brake system

Unfortunately, ALLData has no information at all on the 1968 Bus, so I cannot do much more than guess, but I will take a shot. Does it have power brakes by chance? I do not recall the bus having that, but if it does, then I would think either a nasty vacuum leak around the brake booster, or the booster itself. Since the bus probably does not have a booster though, I would think the master cylinder is leaking internally. That is, the piston inside of there has a couple of rubber o-ring seals on it. They are allowing a little fluid to slide by them, causing the soft pedal issue. As you work the system a little, they get a little wet, and swell just a bit, causing them to seal just a little better, resulting in better pedal pressure.

Again, I am not terribly familiar with the bus, but according to my general experience with master cylinders, that is what I would look at.

Also, for some reason I just love your screen name. Cannot seem to figure out why though. ;)

Good luck and let us know.

It sounds like the brakes need adjusting, 1968 I believe is still drum on all four corners, they need to be adjusted so there is very little free play before they apply. Drums are worse for this than discs. Also, check the front wheel cylinders for any that may be sticking as that causes this issue because the other cylinder and shoe tries to compensate for the sticking one. If you want to see a lot of VW bus help, go on YouTube and look at vwdarrin and Mustie1.

If you have not changed the brake fluid, that could be causing some issues too, as it is dirty and thinned out from years of being heated and cooled. You can try flushing and bleeding the system. Here is a general how-to guide: https://www.2carpros.com/articles/how-to-bleed-or-flush-a-car-brake-system

Genius! Steve I did not even think of the fact that that is a drum brake system. That makes sense. Scratch what I said and do check into doing that adjustment.