Astrovan hydroboost help please

[Barrrf]

I have the booster and master from a 95 astrovan all installed. I tried to connect a brand new set of brake lines. I'll try to explain. On the master, the front port fitting screws in correctly but in the distribution block the fitting is slightly too large. On the rear of the master, the fitting is slightly too large to screw in but the other end screws into the rear of the distribution block correctly. Anyone know what fitting and sizes I need to make this work?

[a67]

Using RockAuto for dimensions, they list the ports as 1/2 x 20 and 9/16 x 18, 45° inverted flair. This surprised me as I expected metric bubble flair. Apparently not.

Even the pictures show an inverted flair seat in the M/C. The distribution block is likely the same SAE inverted flair. I know from experience that some bubble flair tube nuts do thread into inverted flair fittings. But there is very little thread engagement due to the lead in before the threads start. So be sure that you are using inverted flair tube nuts.

It is easy to tell the difference between the inverted flair and bubble flair tune nuts. An invert flair nut has the threads starting right at the end of the nut.

A bubble flair tube nut has a blank lead-in area before the threads start.

Bob.

[Barrrf]

Yeah it's definitely English. The factory Chevelle lines only work in half of this.

Also thanks much for finding that info. I checked on rock and didn't see it. I'm apparently blind. I owe you a beer.