Master cylinder brake line replacement

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dustymopar

dustymopar

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Hi, I need to make a brake line from may new master cylinder to the splitter block. Could someone tell me what size / diamter this line should be (if not 3/16) and what size fittings I need? Manual single circuit brakes.

The existing MC does not have a line so have nothing to compare with?

TIA
 
It would help if you volunteered the year and model of your car. My 64 & 65 single-pot MC's had a 1/4" tube w/ double-flare. The matching fitting on the MC and splitter block is termed "1/4" female inverted flare".

This would be an opportune time to change to the much safer dual reservoir MC. Many have done so. I went power booster on my 65 Dart and am converting my 64 Valiant to manual, both newer aluminum MC's. To do this, get a "1/4 M to 3/16 F inverted flare adapter" for the top port of the splitter block and a "3/16 inverted flare plug" for the rear port. Also get a 3/16 inverted flare coupler to attach to your existing rear brake tube.
 
You wouldn't happen to have pics of the finished install do you?
 
for reference only-- this is from a 73 dart sport (brown car manual disc brakes)
& a 75 Duster (red car power disc brakes)


one of these set-ups should be similar to your avatar picture. Lawrence
 

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Sorry, the Car is a 66 Valiant, single circuit manual.

Bill, so I use a 1/4" line and the fittings are 7/16 unf?
 
Unless it is a show car I would not even consider repairing a single circuit system. The added cost and effort of a dual master is worth it. With single circuit you are always 1 leak away from a wreck.
 
Yes, you are right. There is a specific reason for getting the existing system going and will be a temporary fix. Once there, can convert it in the near future.

At this stage, I just need to know for sure what size line I need (1/4") and fittings (7/16"??).....
 
dustymopar,
Sorry I don't know the size of the nut used with the 1/4" tube, but it is the smallest size that fits that tube.

None2Slow,
I am currently installing the dual master in my 64 Valiant, so will try to post photos. Actually, I am working on my house, but ...
The link that VDART gives is great and they do say 7/16" thread for the top 1/4" port of the splitter block, so should be the same on the original MC side. They don't give PN's, but I got them at Autozone on the brake fitting spinner display.
 
I am going to be installing Wilwood brakes that mount to the 9" spindles. I am going to need to upgrade the MC for sure, so Im researching while I can. I have also thought about using the Wilwood MC. Anybody use that?
 
There is a duster body out at local jy that has disc brakes on it. I would like to install them on my 64 Barracuda I was wondering what year should I use for a master cylinder? Car will be manual disc. thanks for all help.Steve
 
Looks like I have worked it out - thanks guys. It lloks like the OEM line should be 1/4" and the fittings 7/16 unf". I have the fittings to make a 3/16 line. Do you think that would make a big difference?? Added brake pedal pressure perhaps?
 
dustymopar said:
Looks like I have worked it out - thanks guys. It lloks like the OEM line should be 1/4" and the fittings 7/16 unf". I have the fittings to make a 3/16 line. Do you think that would make a big difference?? Added brake pedal pressure perhaps?
Click to expand...

You can't connect a 3/16 tube to a 1/4" tube inverted flare fitting. The double flare will be smaller and will not seal. I know you can get 3/16" nuts that will screw in, but that doesn't mean it will work. A simple solution is to get a 1/4" M to 3/16 F inverted flare adapter for ~$4 at Autozone. You might also change the fitting on the MC. I THINK (verifty) that the MC port is an NPT thread.
 
Bill, I have an NPT adapter for the MC but there is a inverted flare on the ditribution block, so as you suggest, a 3/16 will not seal there. Good point and thanks for that!

I will get the correct fittings and take it from there.

Point taken on the dual circuit thing, will seek to upgrade to this asap

Thanks everyone!
 
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