I've just purchased the JB1133 7/8" master cylinder from the 240k or 260z and thought from reading on the forums it has a residual valve for the rear brakes (the front brake line on the master) which is needed becasue the 240K and 260z have rear drum brakes.

I went to remove the valve, and found that both the front and back brake lines from the master have some kind of valve thing in them? Or are they something else? What should I do, remove both, or keep both, or just remove the rear brake one...? I dont even know what it's meant to look like, you can see in the pics below..









By the way, anyone else looking to purchase this master (I read a few people asking where to purchase them) your local supercheap, repco, datsport or anywhere has them I found supercheap to be the cheapest but then went to a place at rocklea in brisbane called all brake clutch or something, and are a bit cheaper and got from the warehouse within 2 hrs for me.. pretty good guys too, the place name might be a bit wrong but its something like that.. ipswich rd.

And another plug
I've now got no use for my old master cylinder unless i decide to go back to it... its a 15/16" JB1361 original 280zx item by NABCO. it will need a resleeve for $160 by the same group above in rocklea, but after that will be like brand new. apparently these are the really hard to find and expensive items that i've read about in other threads. I'll keep it if my current one doesn't work out or whatever..

Have a read here: http://ozdat.com/forum/viewtopic.php?f= ... 7&start=15

BTW, Why are you going down to a smaller M/C?

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Classic Auto Fabrications:
http://www.ozdat.com/forum/viewtopic.php?f=38&t=31659

http://www.lescollinsracing.com/

Thanks for the link/read, its quite good but some of the important pics don't work and some questions unanswered, especially the last post :
Like in my pic they both look identical, i havent pulled them apart to check the slits in them but i don't wanna do that if i don't have to.
So, should I go back to the brake joint and ask them or just like someone said remove the rear one and put slits in it myself (which is dodgy in my opinion) or just remoev it completely, but then why remove it completely if the front line has one and it seems its meant to be there.

I'm just tryin to get this done tomorrow if possible the brake place isn't open til monday obviously.



And i went down to a 7/8 as i think that will suit my brake setup more than a 15/16 as it is a bit harder to press in than i like and doesn't travel much. if its bad I'll change back.

Mine had 2 valves, with grooves in the front circuit valve but not in the rear. My brake shop guru said putting the grooves in them is OK and it is also OK to completely remove them. With my 1" MC I put the grooves in and it worked OK, with my current 7/8" MC I removed them both and it also works OK. Apparently the brakes can be hard to bleed without the valves but mine is OK.

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Track car: 1970 1600 Sedan, L18
Gravel car: 1981 Bluebird Wagon, L20B

Cheers
How do you put such little grooves in them accurately? What did you use? I haven't yet pulled them apart but was hoping not to pull them apart until i knew exactly what i was doing.
Basically do you just replicate the front brake line valve...?

Yep, replicate the front valve. I used a dremel with a pointy diamond bit, but a very sharp knife probably would have been neater. I'd just try it without the rear valve though.

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Track car: 1970 1600 Sedan, L18
Gravel car: 1981 Bluebird Wagon, L20B