Could someone please post a pic of their 240z brake check valve?  I can’t locate mine maybe it doesn’t exist  

My running, almost rust free 1973 240z scraed me a bit on my first drive yesterday. The brakes are horrible. Feels like when I botched a bleeding on my wife’s brakes years back. 

Lots of pedal effort with just gradual slowing. Applying brake while idling causes an increase in RPM. A squishing airish sound when the brakes are first applied. 

I was originally thinking it was definitely the booster.  Then I started to wonder about the check valve.  I can’t even find the check valve.  I assume it’s on the vacuum line somewhere between the brake booster and the engine.

Assistance would be greatly appreciated.

 

The check valve may be missing but I still suspect the booster is bad...

I agree with Patcon---diaphragm is ruptured or reaction disk has dropped---the pedal effort, increase in rpm and squishing airish sound are all telltale for one--the other-- or both.

Crappy photo of the check valve location-----look just below the hood opening and just above the throttle linkage at the firewall----the check valve holder is above and  to the left of the brake booster---follow the hoses, round and black with a little red showing---the red is the check valve.

 

 

Thanks guys. Ordered a brake booster from O’Reilly yesterday. Autozone couldn’t sell me the right one. Bummer, because their Black Friday deal was better.  

The brake booster totally fixed it.  Doesn’t stop like squishy death anymore. Thanks dudes. 

@ AndyStep12 Where did you pick up your brake booster?  I have the exact same symptoms on my '72z  that you described.  How difficult was it to install?  Thanks! 

I bought the smaller 240 one from amazon.com.  after returning the core I think was about $100.  Had to paint and installation was a real tough job for me.

A couple of things that I figured out that maybe useful.  Take a wire and attach it the the master cylinders then to the ceiling for me but you can figure something else  but if you secure the MC you won't have to remove the lines, just unbolt from the booster and move it out of way.  Loosen the nuts above the pedals first, that was the hardest part for me.  I'm no yoga person and getting under there was a PITA.  

Get a razor blade and remove the OE red sticker off the old one. Paint the new one and glue the red sticker on, looks like 1972 again.

Good luck.

47 minutes ago, siteunseen said:

Loosen the nuts above the pedals first, that was the hardest part for me.  I'm no yoga person and getting under there was a PITA.

Second that.  The top two nuts are hard to get started on their threads when reassembling.  Kneel on garage floor, lean in off balance, then then try to make arms reach back to the left so that two or three fingers holding nut can find their way into dark, confined recess.  Wins my vote for 'Top 10 Most Difficult Fasteners'.  Other nominations?

As hard as it was I think I'd go to the larger 280 one if I had to do it again.  Something to think about OP. 

Blue's tech tips has a good write up on the upgrade, fyi.

15 minutes ago, Namerow said:

Other nominations?

The heater and radio faceplate? was a nightmare for me. Tough as hell also old fragile parts that are NLA. 

Give me a minute,  I'm sure I can think of others. 

 

Have you tried to install a headliner by yourself and make it look good? I never want to do that one again.

26 minutes ago, Namerow said:

Second that.  The top two nuts are hard to get started on their threads when reassembling.  Kneel on garage floor, lean in off balance, then then try to make arms reach back to the left so that two or three fingers holding nut can find their way into dark, confined recess.  Wins my vote for 'Top 10 Most Difficult Fasteners'.  Other nominations?

What I did was to build a bench that was about the height of the door sill. I could lie on my back and reach up to get those nuts. It was much more comfortable that way.