1971 brake master cylinder
 

I will try to keep this short. 1971 240Z, and I know that I have to change the master cylinder. Found one from Rock Auto, decent price, ordered it, and got an invoice clearly stating it was for a 1971 Z....Compared it to the bad unit on the car... clearly different.. researched extensively, contacted Rock Auto and asked... got a bit of a run around... found out the information about the different series Z's in 1971; January through August and then, September on... another series.. Haynes Manual shows diagrams of both 240 and 260 master cylinders (cross section view)... they reservoirs and guts are reversed.. Another manufacturer asked for the month the car was manufactured.. read several forums on that and found out the VIN number etc. is no help, but I suspect this car was made somewhere between January through August or even in 1970 and therefore, had an earlier version of the master cylinder.... I am strongly leaning towards sending this one back to Rock Auto... instead of "taking a chance"... as they suggested... they won't be driving down the road... Anybody got any ideas? The next step for me is to contact a manufacturer...

Well.. I tried to keep it short.... please advise if you have run into this problem... PS... you can tell the difference in the master cylinders by looking at them... two reservoirs... one big, one little... on the 260 they were in opposite locations....

Thanks for any help...

You can move the plastic reservoirs but that is moot.

My understanding is that the front and back cylinders have different valving in the bottom of the master (where the big nuts are). You can swap these around too.

OR you can bend your brake lines to match F and R accordingly.

Interesting......
 

The jury is still out on this one as well... I have contacted so many parts outfits and no, they are not experts and admit they just publish what is sent to them from the manufacturers, who do not take much into consideration... For example, the model year ends and the new one begins in the August/September window.... so you can have a 1971 Z, like me, that will not accept 1971 parts... so most of the searches for parts I do, I also cross reference with a 1970 Z search to make sure.... One company still insists that their new one size fits all master cylinder works on all cars..... What I did was pull the top plastic reservoirs off to inspect the cylinder... and found that the filters inside the plastic reservoirs were clogged... so that was quickly resolved, and the remainder of the cylinder looks good... so I topped it off with brake fluid and will know more the first time I take it around the test block as far as how good the brakes actually are... I hesitate bleeding them until I know for sure there is a soft pedal... and a problem.... old brake bleeders are notorious you know... Had a Honda motor cycle with a broken off bleeder, and actually bled the thing by loosening and tightening the brake hose... don't laugh... it worked!! Time will tell.... and that time may be coming soon.... live in MN and the forecast is for at least one and a half more weeks of crappy weather.... more time to work on the car... but I would rather be test driving it.... today, it gets the molding installed and the windshied wiper motor removed to test the linkage to see if it is free... and if so, I will bench test the motor... but I am 99% sure the motor is gone.... and I have a Honda motor lined up to replace it with.... seems like the easiest and cheapest solution.... rambled enough... time to go to work... thanks...

I didn't know about removing the check valves for disk brakes.