I am finally getting the time to replace the clutch master cylinder and slave cylinder on my 72 240z, I am hoping this will fix my problem. This is my first attempt, I was hoping someone may have some suggestions and advice. It looks pretty straight forward but all the info I can get before hand will be helpful. I believe the system will need to be bled after installation? Thank you.

I have not gone through this process before, but you definitely have to bleed the system after the new parts are installed.

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Phil
1981 280zxt - Now in the care my son!
2014 370Z Sports Touring Roadster

What are the problems being experienced?

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-Chris

I've replaced both master and slave (slave twice) over my 71 Z's life. This is a pretty straigh forward process and pretty easy to d o.

Be careful not to spill any fuid on your paint.

Bleeding will be required. Have buddy pump clutch pedal as you open and close bleeder valve on slave cylinder.

I find that periodic bleeding of brakes and clutch really help extend the l;ife of the cylinders. Remember, brake fluid is hydroscopic (absorbs water) so use fresh fluid and bleed once evry 2 years or so.

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John Kish
1971 240Z - original owner

Jeff, of all the projects you could have choZen to DIY, this is probably among the easiest....not saying nothing could go wrong.

My first consideration would be which parts to get and where to buy them. Many 240Z owners decide to swap over to 280Z parts when they make this change, altho I don't know why. The performance of the 240 unit is fine for well over 100,000 miles if you change the fluid occasionally. Not sure what the advantage of a 280 unit would be (anybody?), but there IS a certain complication if you decide to do that. The operating rod btwn the pedal and master cylinder is a different siZe on those two units. That's enough reaZon for me to leave things stock.

Anyway, we (CTZCC) get discounts on our partZ from RockAuto and Executive Nissan in North Haven, so unless you already have your partZ in hand, you can save a few bucks by going thru them.

Like Johnny said, be sure not to spill any fluid on your paint. Have an "emergency flood system" at hand in case you do. It doesn't take long at all for that stuff to bubble your firewall or framerail. The damage will be done by the time you return from running around the garage in a panic looking for clean-up gear. And use a small funnel when refilling your new master cylinder to make sure you don't get sloppy.

Be kind to your fittings. Consider replacing them (and the hose) during the swap. The hose often gets overlooked, but it's the most-likely thing to fail under use. Yes, you CAN shift your Z car without an operating clutch cylinder (ZMan and I have both lived with that), but it's a bear to drive in stop/go traffic that way.

I think the best thing I can add to your project from personal experience is to somehow mark and duplicate the adjustment of the slave cylinder rod before you reinstall it. Installation was easy compared to adjustment (for me). My 240 seemed to have an adjustment 'sweet spot' only about 1/8" wide ~ too much one way, the clutch slipped under acceleration; too much the other way, the disc didn't separate cleanly enough for a smooth shift. The proper adjustment was a very precise setting.

I remember spending days under the car (once I got it jacked or ramped up), loosening the locknut, screwing the adjusting rod in or out, reseting the locknut, dropping the car and retrying the results. Once I finally found the exact spot, I painted it with my gf's nail poiish (still remember that fight!) so I knew exactly where to adjust the rod if I ever removed it again.

I would very carefully measure how far the rod emerges from your old slave cylinder, then start by trying to duplicate that exactly on the new unit. It will give you a ballpark place to start.

Frank


*(But like Phrog asked, what problems are making you exchange partz?)

In the pics posted by Frank, note that the slave has a tang below the fitting for the return spring. Not all replacements have it even tho they say they are for this car. Also, some replacement slaves come with a non-adjusting rod, don't be afraid to re-use your original if that is the case.

On bleeding the system, I found that gravity handled it all quite well. Uncap the master and open the slave bleeder to see if it runs freely.

Good luck and as the others say, this is one of the easy ones as long as you observe all the precautions regarding that nasty and corrosive hydraulic fluid.

Jim

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Jim Arnett
Richardson, Texas
HLS30-15320 12/1970 (original owner)
ZCON 2015 Gold Cup - Street Modified class

Just a note - Jeff said he has a 72 Z - they came with the self adjusting slaves - no return spring, no adjustment to the rod.

FWIW,
Carl B.