Dual master rear line routing

[Jon B]

Hi all,

Happy Labor Day! I'm converting to a dual master cylinder and looking for ideas on running the line for the rear brakes. I eliminated the "firewall crossover" since I'll no longer have a booster and am running a pedal-activated brake light switch, and want to run the line down the driver's side. It's really tight especially around the shift linkage. Is there anyone who's gone down a similar road and can share some thoughts or pictures? Thanks in advance!

-Jon

 

[Forrest39]

Hi Jon,
I am planning on a dual master as well. I bought the Courier MC from summit as well as some metric to SAE adapters. I thought it was a good idea to have a way to adjust the front / rear bias so I elected to get a Wilwood proportioning valve and mount it where the booster was. I know that's not what you asked, but I figured you might find the alternative datapoint interesting...
When planning the plumbing for the rear brakes, I thought the same thing that you did. No need to run it across before running back. I thought I would run the front line down the left side and have a union on or near the crossmember like stock just swapped from right to left. That configuration presented two conflicts. The steering knuckle, and a crowded left side firewall considering all of the plumbing for the clutch. I think the clutch plumbing is less that ideal considering how close it is to the exhaust system. Putting the rear brake plumbing that close to the exhaust just doesn't seem like a recipe for success, so now I understand why the factory ran the rear brake line through the inner fender well and down the frame rail. The down side of doing that down the left side is that it might mean drilling a new hole.
About the only other place to run a rear line would be in the middle of the tunnel, or perhaps just left of the middle. I ran a fuel injection line and return down the right side middle of the tunnel and found this to be a good choice as it keeps the plumbing away from the exhaust. It might be a little tough running the plumbing with the engine / trans in place, but easy to do if they are pulled out.
Whatever you decide, I think the dual MC is a good idea if you can afford the minor departure from stock.
Good luck! -Kevin

 

[66TigerMK1A]

Hi Jon

I installed a Nabco dual master from a '79-'82 Nissan 280ZX years ago. I had talked to Dale about sizing for my 4 wheel disc brake setup and he had recommended 15/16" which is what this one is...
I don't run a booster

I'll add some pics..

The rear outlet pipe ( front brake ) goes down through an existing hole in the left inner fender that a P.O. drilled for cooling?? and it goes to the left caliper but has a 't' to send it along the cross member to the right front brake. The front outlet pipe ( rear brake ) comes up on the left inner fender to a 't' that goes through the proportioning valve and then down the left side of the tunnel back to the rear brakes. I got a brake light switch with NPT thread and it's also mounted on that 't' .The original brake light wire that went from the fuse box all the way over to the switch is now only about 6" long
Underside shot shows the line running past the ground strap and I think I ran it through the 'Alpine exhaust' hole in the x frame. I'm running a T5 so no linkage although I don't think it would be an issue as I think I did this mod before I took the toploader out last pic shows it crossing over to the passenger side and running along side of the fuel line

 

[Jon B]

Thank you both for the info, and thank you Jim for the great pics! I think I'll go with the "Alpine pass" method. I plan an eventual upgrade to a T5 or Tremec, but almost feel like doing it now to simplify things haha. I can always redo it when (not if) I pull the engine and trans. Thanks again!

-Jon

 

[whiskytangofoxtrot]

I also routed mine through an exsiting hole in the left front fender to the front. I routed the rear down the trans tunnel and then through the old alpine exhaust hole. i thought it was a great idea until I pulled the engine out. My old set up had a lakewood bellhousing that was too wide for the tiger, and was actually rubbing on the line. I re did the line still going the same route but with a stock housing