Brake line fitting size/thread

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Spook50

Skål
Supporting Vendor
Joined
Feb 16, 2005
Threads
764
Messages
7,270
Location
Spokane, WA
Quick question: what's the size of the fittings that go into our master cylinders? I'm hoping to find a GM one that'll have the same size ports for when I do the hydroboost conversion.
 
What are the chances of finding an adapter to run dash fittings instead? I found it a lot easier than flaring, bending, swearing, reflaring etc.
 
Bret said:
What are the chances of finding an adapter to run dash fittings instead? I found it a lot easier than flaring, bending, swearing, reflaring etc.

Dash fittings???
 
I think they are 37' flare fittings. They should be the same style connectors you use on the jets. You sometimes see them as -3 or -4. Here is a picture of the adapter and the line. For more go to http://www.anplumbing.com/shop/

I haven't bough anything from them but it should give you an idea.
 
Last edited:
Yes these are called AN fittings (AN stands for Army/Navy). Aeroquip and Earl's carry them. Most of your brake lines will be -3 (3/16) or -4 (1/4). Fuel lines will be -6 (3/8). I have used these on many builds and for a leak free connection and they are the way to go. You can get them in steel, aluminum and titanium. I've picked up adapters for ISO flare, metric flare, banjo fittings etc... THe only drawback is that they will cost alittle more and you need a special 37 degree flareing tool. Seamless stainless tubing (.030) works great and you don't need to double flare. Anyhow my $.02.....Dave
 
Bret said:
I think they are 37' flare fittings. They should be the same style connectors you use on the jets. You sometimes see them as -3 or -4. Here is a picture of the adapter and the line. For more go to http://www.anplumbing.com/shop/

I haven't bough anything from them but it should give you an idea.

Looks interesting. I'm not sure if we keep anything in our bench stock that'll work for my brake lines, but it seems like a good way to go. It doesn't solve the problem of finding the right fittings (or adapters) to connect my brake lines to a GM master cylinder though...
 
Spook- Try NAPA, several years ago I bought some Weatherhead fitting from them to adapt the ISO metric (bubble) flare to a standard 45 degree, double flare. Come to think about it I may still have them but they are around 3/16.

Dave
 

Users who are viewing this thread

Back
Top Bottom