Brake M/C line fitting threads

[YY1]

I've read in a couple places that the lines going into the master cylinder could have different sizes and/or thread pitch for different years. Anyone know the specifics of that?

I have a couple of what I think are 70-74 dual disk Masters, and the one from my 87 5th Ave, plus the MP kit M/C, that looks just like the 5th Ave part.

The intended use is the 66 Coronet. I'm pretty sure I need new lines, as there's only one from the factory, and the 5th Ave has really short ones. I found a set on ebay for $18, that says "68-70 PDB". I really don't think the "power" part matters.

I did try the front reservoir line (rear brake) from the 5th Ave in one of my 70's M/Cs, and it appeared to start to thread, but they are pretty rusty, and I didn't want to push it. I sure don't want to force it if the threads are different. I'd love to chase them with a tap.

Thanks.

 

[68sportsatelliteragtop]

I've read in a couple places that the lines going into the master cylinder could have different sizes and/or thread pitch for different years. Anyone know the specifics of that?

I have a couple of what I think are 70-74 dual disk Masters, and the one from my 87 5th Ave, plus the MP kit M/C, that looks just like the 5th Ave part.

The intended use is the 66 Coronet. I'm pretty sure I need new lines, as there's only one from the factory, and the 5th Ave has really short ones. I found a set on ebay for $18, that says "68-70 PDB". I really don't think the "power" part matters.

I did try the front reservoir line (rear brake) from the 5th Ave in one of my 70's M/Cs, and it appeared to start to thread, but they are pretty rusty, and I didn't want to push it. I sure don't want to force it if the threads are different. I'd love to chase them with a tap.

Thanks.

I believe the threads are pipe thread sizes.3/16, 1/4, 5/16, I have been having a hell of a time with the lines from the mc to the junction block. All the parts stores sell are 1/8 lines with 2 small fittings or an adaptor piece about 6" so you need to use a coupling. I finally broke out the double flare tool and reused the old fittings on the new lines .BTW isn't the front half, larger capacity and closest to grille, the front brake reservoir? That is how I hooked mine up.

 

[5.7 hemi]

Some of the mc fittings are 9/16 and 1/2 inch. Just use your original fitting if possible and get some new line and make your own as 68sportsatty has suggested.

 

[YY1]

I think the m/c is either the same capacity for drum/drum or the rear reservoir is much larger and for the front on disk/drum. The lines I found on ebay are very reasonable, like $20.

I tested my older m/c and one was clean but never pumped out the line side and the other was cruddy. Any place still take them as cores? Might try rebuilding the clean one if I can get a kit.

I think I'll just buy the ebay lines.

http://cgi.ebay.com/ebaymotors/ws/e...0166089244&viewitem=&sspagename=STRK:MEWAX:IT

Didn't see any on rockauto, but didn't look too incredibly hard.

It's been a long time since I double flared anything, and I don't have any old ones the right size. That stress loop looks like an SOB to bend. $18 plus shipping looks like a bargain.

 

[Meep-Meep]

I was just fiddling with that stuff tonight. I'm installing a line lock and had to make a new line along the firewall. Lines are not hard to make and that big loop can be made by wrapping the line around a small soup can. Your thumb can make a good bending mandrel too. Still $18.00 is not bad for a set of lines plus you will have really nice factory looking lines with the nice tight bends.

The thread sizes are the same as a regular fine threaded bolts. The 9/16" nut is 9/16-20 and the other is 1/2-20. The distribution block has 3/8-24 and 7/16-20 sizes. My problem is I'm having trouble finding a 7/16-20 coupling but for the 3/16" flare. All the ones I find are for a 1/4 line.

 

[YY1]

Hey Meep, I had a 71 Torino GT. Nice, clean car. 351C 4V, shaker, a/c, car. Loved the bodystyle. Only thing I wished it had was hideaways. However, it didn't handle nearly as well as even my 60's non-swaybar Mopars. Got a pic of your Ranchero?

 

[Revhendo]

I was just fiddling with that stuff tonight. I'm installing a line lock and had to make a new line along the firewall. Lines are not hard to make and that big loop can be made by wrapping the line around a small soup can. Your thumb can make a good bending mandrel too. Still $18.00 is not bad for a set of lines plus you will have really nice factory looking lines with the nice tight bends.

The thread sizes are the same as a regular fine threaded bolts. The 9/16" nut is 9/16-20 and the other is 1/2-20. The distribution block has 3/8-24 and 7/16-20 sizes. My problem is I'm having trouble finding a 7/16-20 coupling but for the 3/16" flare. All the ones I find are for a 1/4 line.

Try here.
http://www.plews-edelmann.com/brochure.cfm?brochure=1869&location_id=2516

 

[Revhendo]

I believe the threads are pipe thread sizes.3/16, 1/4, 5/16, I have been having a hell of a time with the lines from the mc to the junction block. All the parts stores sell are 1/8 lines with 2 small fittings or an adaptor piece about 6" so you need to use a coupling. I finally broke out the double flare tool and reused the old fittings on the new lines .BTW isn't the front half, larger capacity and closest to grille, the front brake reservoir? That is how I hooked mine up.

They're not pipe threads, they're SAE fine thread. With respect to what we work on here, tube nuts come in standard sizes. 3/16 has a standard size of 3/8-24, a 1/4 tube will have a standard size of 7/16-20 and so on.

Brake components, (Master Cylinders, Prop Valves), will use tube nuts of different threads for some lines to prevent getting circuits crossed. That's when you find tube nuts that are for 3/16 line but have a 9/16-18 thread.

 

[68sportsatelliteragtop]

They're not pipe threads, they're SAE fine thread. With respect to what we work on here, tube nuts come in standard sizes. 3/16 has a standard size of 3/8-24, a 1/4 tube will have a standard size of 7/16-20 and so on.

Brake components, (Master Cylinders, Prop Valves), will use tube nuts of different threads for some lines to prevent getting circuits crossed. That's when you find tube nuts that are for 3/16 line but have a 9/16-18 thread.

You're correct Rev. I spent some time digging through all the ends I've gathered over time and some are oddball pipe thread but most are, as you said, fine thread.I finally got my set up together and ended up using the factory fittings on new lines that I double flared. The CPP disc brake conversion kit I purchased off E-bay ended up not being the value I had hoped for as I had to purchase new calipers and hoses, the ones supplied were junk.Thanks again for your help.

 

[Patrick]

Take your master cylinder, perportioning valve and lines to the parts and get everything you need matched up, or buy a disc brake set of lines for a 70,71 B body from fine lines.