Hi guys, I’m just in the process of researching and changing out my master cylinder in favour of a Datsun 120y. I’ve just mocked up the Mc which looks good but I’m unsure as to what way the outlets fit up (ie which port goes to which brake😅)

Also my mk2 has the portpotioning valve from the late models but do I actually need this now as I think it’ll make it easy to plumb up all the brake lines direct from the Mc? I don’t mind making custom lines to suit or at least giving it a go! 🤣

Any help would be appreciated! 👍

Do you have rear disc brakes? In the standard set up the proportioning valve gave more pressure to front discs and less for rear drums. I have rear discs and have found that I should have taken out the valve as the front discs lock up a bit under heavy braking. Len

The pot with more fluid capacity always goes to the front.
If you have rear disks an easy way is to delete the proportion valve and install a inline bias tap on the rear line, this can help dial out the rears locking up early. Install it in the engine bay and it'll be legal.

Thanks for the info guys, I was planning on keeping the rear drums in at this stage. With the Datsun 120y Mc it has the two pots one for the front and one for the back yeah? Was just planning on simplifying the whole system but wanted to make sure I’m not going to mess up the whole thing by taking out the proportioning valve! 😅

Yes there's 2x pots, the front one (headlight end) which is shorter and hold less fluid, this goes to the rear brakes. The pot behind that will feed both the fronts however mk2 have the proportion valve do check and label which one goes where, draw a map of needed so you don't get lost or confused with it all.
I removed the valve in my panelvan as I wasn't sure it works or not and a rebuild costs a second mortgage ! As I was fitting a new Ford Laser TX3 master cylinder (and hot rod vacuum booster) , it has a valve in the master so the Escort proportion valve was rapidly binned.. the van runs stock calipers and drums n works a treat..

My way of thinking is that the Datsun never had a proportion valve (like escort mk2) so in theory it's well,say, redundanted . Although if the proportion valve is working fine I would leave it there as it's a mess to change pipes to match up..