Hi, I gotta get this 2004 ford e150 van going. I need to test the master cylinder. Does anyone know the brake line thread size so I can buy a couple brass plugs?

 

According to OReilly's website they're 3/8"-24...

 

thanks I try it. Had a time figuring out the the other fitting sizes. They were metric, not what all the parts stores were showing.

 

Nope. way bigger. Perhaps the replacement units are 3.8/24 but not the original. Its around 1/2" but it's metric im pretty sure. So i'm guessing if I replace it ill need adapters as well because no sense redoing the lines..

 

I agree there's no sense in redoing the lines.

Be real careful of thread pitch... 1/2" is pretty close to 12mm. I've seen 12mm inverted flare with 1mm and 1.5mm thread pitch. Also, SAE 1/2" is usually 20 tpi which is close to 1.25mm pitch (actually 1.27mm).

Let us know what you discover for future reference.

 

Before getting involved going into a rabbit hole, why do you feel the master cyl requires replacement ?

What symptoms are you seeing that cause you to feel the master cyl is/has the problem ?

 

Buy a thread pitch gauge anywhere they sell hand tools. You can get one that has both standard and metric threads and they cost less than $20. It'll come in handy many times.