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I'm planning to replace the lines between my M/C and Prop Valve, was wondering if anyone knows what the size/thread is for the two inputs (ports) on the Prop Valve. It's a stock '78 F150 M/C and Prop valve setup for a disc/drum. (would keep me from having to bleed the brakes twice since I'm still driving it until swap day). Thanks
Not sure, but I took extreme care when removing mine, and reused them.
Mine came off easily enough with line-wrenches, but if you think yours will be a problem, you can always cut off the old line close to the fitting, and simply use a nice tight fitting socket to bust it loose.
I did just see a page with the sizes in the last week or so, but I can't remember where...
I'm planning to replace the lines between my M/C and Prop Valve, was wondering if anyone knows what the size/thread is for the two inputs (ports) on the Prop Valve. It's a stock '78 F150 M/C and Prop valve setup for a disc/drum. (would keep me from having to bleed the brakes twice since I'm still driving it until swap day). Thanks
Easy enough. The primary line coming from the rear most port of the MC will go to the end of the valve that has 3 ports in it. This fitting (on the brake valve) is 1/2"-20 for 3/16" diameter hard brake line tubing.
The line coming from the secondary port of the MC (the forward most port on the MC) will go to the end of the valve that only has 2 ports in it. This fitting (on the brake valve) is 3/8"-24.
3/8"-24 is the standard 45° inverted flare nut fitting for 3/16" diameter hard line. You can get the 3/8"-24 fittings individually from the parts stores.
The 45° inverted flare nut 1/2"-20 fitting is not a standard fitting size for 3/16" tubing. It's a specialty size that the majority of parts stores will not carry (this is usually the part in the scene at the parts stores where they point you to the fitting adapters parts bin). Adapters are ugly and non-professional looking.
Not to fear though. The 1/2"-20 fitting for 3/16" tubing can be bought brand new from Classic Tube under part number ST8007 (color code Black).
Thanks UltraRanger - that was exactly what I was looking for. Just placed an order with Classic Tube for the fittings.
You're welcome, sir.
The other two fittings at the forward end of the valve, that goes out to the left and right front calipers, are also 3/8"-24.
The fitting in the proportioning section, at the rear of the valve, that goes out to the rear brakes, is another odd-ball specialty fitting size for 3/16" tubing that you most likely won't find at the parts stores. It's a 9/16"-18 inverted flare nut. This fitting is also available through Classic Tube under part number ST8010 (color code Gold --although, it looks more like olive drab to me).
You may also find one more specialty sized fitting in your brake plumbing that's not a standard size for 3/16" brake tubing. It's a 7/16"-24 inverted flare fitting. Also available through Classic Tube under the part number ST8006 (color code Red).
Sounds like you're pretty well set then and, if you should need more fittings that aren't available from the parts stores, you know where to get them now.
If you'd like to add some protection to the lines or just make them a little fancier looking, you can also get gravel guard through Classic Tube. You can get it in either stainless steel or OE coated steel. This is the OE that I used on this booster installation this past September on a '72 F100 Sport Custom that belongs to a friend of mine. (Classic Tube part number for the gravel guard is AG1435OE).
Setup I had installed and plumbed in my own truck in 2014.
