3G brake master cylinder upgrade

[Vic321]

I've just done an evo brembo swap to my 90 gsx and need to upgrade to the 3g master cylinder. Can I use a union on my factory hard line and just connect a new piece of hard line to reroute the stock line to fit the 3G master cylinder? I'm trying not to mess with removing the whole line if I can.

 

[Soccerguy136]

If you are asking if it is possible to attach a piece of new brake line to the factory hardline and bend it to accommodate the new master cylinder, yes it is possible, though probably not the best way to go about it. But that's not what you asked so here goes.

You can buy already double flared lines in various lengths at any auto parts store. 3/16 for the brake line and 10x1.0 for the fittings on the line. If you buy the green kind you can very very carefully bend it by hand, but it is always best to use a tubing bender. Doing this allows you to use a single line and connect the factory fitting to the new line. That would be the easiest way to do what you want. Make sure to bleed the brakes very very thoroughly and test before you attempt to drive the car. The order to bleed is furthest away from Master Cylinder to closest. So first to last is: Passenger Rear, Driver Rear, Passenger Front, Driver Front.

If you have not ever done brake lines before, please don't do it yourself. Have someone else who has done it before do it for you. Brake lines are NOT something to experiment and learn on.

Hope this helps.

 

[Paul@RTM]

I would just add that the 3g master uses M10x1.0 bubble flare ports as opposed to the inverted flare of the 1g or 2g. Not sure if that's what Soccerguy meant by "double flare". In any case it's going to slightly complicate things because at some point in the connection you're going to have to adapt the inverted and bubble together.

 

[Soccerguy136]

I actually did not know the 3g used bubble flare. That is very odd to me. I thought those were only used on British cars?

Anyway, that does makes things slightly more complicated, as you will either

1. Need a line with a "double flare" (or Inverted Flare, same thing) on one end to go to the old line, and a "bubble flare" to go into the master cylinder

or

2. Find an adapter

Here is a good thread on the subject.

http://www.dsmtuners.com/forums/handling-tech/459407-3g-brake-master-2g.html

Thanks Paul for bringing that to my attention! Glad to see I wasn't the only one who didn't know.

 

[dsm4g63t_chris]

I will Snap a picture of my setup tomorrow, I used a banjo and the stock "90*" fitting from the clutch slave cylinder.