Dual Master Cylinder

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me66dartgt

me66dartgt

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Richmond Maine
Can anyone advise what the thread sizes are for a dual master cylinder (Disc/Drum). The MC is a MC36406. I can't find made up lines with the correct ends and need to buy adapters.

Thanks
 
I believe that they are either 1/8" OR 3/16" steel tubing. I want to lean toward 1/8"...
 
These are very likely "proprietary" and they certainly are not "standard" fittings. "Standard" fittings for those lines typically take (I forget) either 7/16 or 1/2 wrench, and they are ALWAYS 3/16 tube

You don't have the original nuts? Parts stores used to sell bushings for those to attach "brake tees" back when trailer brake controllers were hydraulic
 
The fittings are 1/2x20 and 9/16x20. I don't think theres an adapter for 3/8x24 - 9/16x20. You might need to find a nut that's meant for the 3/16 line, and cut & re-flare.
 
I think they are standard "tube nuts", but different size nuts for the front and rear ports (so you can't mix up). The tube sizes for both should be 3/16"D. The only other size I have ever seen is the 1/4"D tube from the MC in early cars w/ a single reservoir (~1966-). Don't ever install the wrong size tube, even if the nut on it fits the port. Always look at the size of the "inverted flare" inside the port. I have never bought tube nuts since I have a box of various brake lines from junkyard picks I can cut off and use. Any U.S. car up to ~2000 should work (almost all are 3/16"D tubing). After that, they started using "bubble flare" fittings.
 
If you can't find the adapters or nuts locally, go to the Inline Tube catalog; it will have these lines premade from the MC down to the proportioning valve. Good fit and quality.
 
BillGrissom said:
I think they are standard "tube nuts", .
Click to expand...

No. Used to sell these damn things. Don't know about this specific situation, but the damn things can be "off" thread. Just like being oversize, the intent was to prevent wrong line installation. Engineers, ya know.
 
Thanks for all of you for the useful info. I changed over from a single pot to a dual and a combination valve for the disc/drum set up. Based on all the feedback it seems that all my lines should be 3/16" (from master to valve and then valve to wheels). I was having a real hard time getting what I needed without having one line from master to valve being a 1/4" and the other 3/16".
 
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