finally ready to redo the brake system in my 81 malibu. have just about everything and just looking everything over. something just does not look right. kept all the old stuff for reference to compare with new stuff (master,prop,calipers,rotors,pads).when i slide the fitting over the new line,the fitting seems to have a larger hole in it than the 3/16 line that goes in it. i know the difference between 3/16 and 1/4 inch lines. i had some old fittings left over from other project brake jobs and was able to use one that looked right. the line is 3/16 nickel/copper. i have the right fitting for the rear of the master but not the rear of the prop valve. is there a metric system that is going to drive me crazy on this project? having trouble with the fitting that goes into the rear prop valve. have not got to the front yet. bought the master from the zone about 5 years ago and it seems to be just like the original one. looks like the front on master takes 1/4 and the rear 3/16. prop valve was from a well known supplier and for my disc/drum. not that well versed on the thread sizes now but looks like that will change soon. just looks like the rear prop valve nut has just a little bit too big of hole in it for the 3/16 line. am i missing something. i can get pics if needed. thanks