Miles

Brake switch. Brake switch adjustment. Short in the wiring. A broken turn signal switch (brake light wires run through the switch). Check the simple things first such as the brake switch adjustment and the brake switch. The brake pedal in the up position pushes the brake switch open (no power flowing). When the brake pedal moves forward the brake switch springs to the closed position turning on the brake lights.

The 72 240Z has the PV in the back (see picture). If you have installed a PV in the back then the stock PV should be eliminated or gutted out. The device under the MC is a hydraulic differential pressure switch. It is not a PV. It also serves as a distribution block. If there is loss of pressure in the front or rear brake circuits a shuttle valve inside moves to the low pressure side blocking loss of fluid and at the same time grounding the wire that turns on the red brake light inside the car. The switch is NLA and there are no replacement parts for it. Every one of these I have opened up the shuttle was frozen in the neutral (middle) position. Don't mess with it. See pictures. Push rod adjustment: The push rod should be almost touching the bottom of the cup at the end of the MC piston. For a starting point see attached picture. Too far out and your pedal will be long and grab when engaged. Too long your brakes will lock up. As a starting point, you have to measure from the tip of the push rod to the face of the diamond shaped spacer 0.53" or 13.5mm. Mine usually ended up somewhere between 14mm to 15mm after several adjustments and road tests. When adjusting the push rod be careful not to drop the reaction disk inside the booster.

The residual check valves hold some pressure to keep the brake shoes close to the drum. Not needed in disk brakes. However, every 280ZX and Wilwood MC I have bought had the residual check valves in the front and rear outlets of the MC.

1. Tell us what year Z you have as there are differences in the hydraulic systems. 2. There are residual pressure valves in the outlets of the master cylinder. They look like a piece of rubber with a spring. Remove them. 3. You should not have two proportioning valves (PV). Having two PVs can cause problems other than what you have mentioned here. If you have for example, a 72 240Z, and you have installed a PV in the rear then the stock PV should be removed. On later model Z cars you need to understand what the PV does before removing or modifying it. 4. The other question is why do you need a PV in the rear? 240SX rear calipers are typically undersized relative to most so called "front brake upgrades". So unless you are experimenting with high friction rear pads to fix front - rear balance issues a rear PV is not required with 240SX rear calipers. 5. You can relieve pressure to the front or rear brake circuits by opening the respective bleeder on the MC if you need to limp home with dragging brakes. 6. In my experience, the front brakes will lock up after a few stops if the booster push rod is too long. It doesn't take much as the return port in the MC is small. The push rod can be adjusted without removing the MC from the car. Just unbolt it and push it to the side. 7. So remove the residual pressure valves, recheck the brake booster push rod length, and road test the car.

-3 TO 10mm x 1.0mm inverted flare adapter is required. See picture. Summit Racing: http://www.summitracing.com/parts/ear-592032erl http://www.summitracing.com/parts/rus-641431

The Toyota caliper was not machined for a banjo fitting. Consequently, the fitting will leak where it is attached to the caliper. Options: There are several companies that sell stainless steel braided brake lines of the correct length and with the correct Datsun - Toyota fittings. Try Silvermine Motors in the Vendors section. You can use A/N brake lines and an A/N-to-Toyota adapter to connect the Toyota calipers. This was my choice because I didn't want to rely on the availability of custom brake lines. There are several discussions about Toyota brake lines in the Brake Forum. Recommend that you spend some time researching the Brake Forum before doing the swap. Are you aware that you may have to go to a larger bore master cylinder with the S12W caliper swap? Stock well maintained brakes are fine for a street car. Stay away from so called "street performance" brake pads as they don't work well cold. If your car is going to be a street or daily driver you want a pad with good cold bite. Cold bite is what you need when a kid runs out in front of you. Quality stock brake pads work fine. See the Brake Forum for details on brake pads and brake swap balance issues.

If the inlet/outlet is too small, and the hose inner diameter too large, you can buy hose reducer bushings at any auto parts store. If you want to spend the time you can find hoses that have different diameters at each end. Or you can buy a universal hose kit and make a Frankenstein hose. No it won't effect performance and don't use hose clamps to make a hose fit on a smaller diameter inlet/outlet. Do it right.

Keep looking.

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On the 240Z the dash light is turned on by a differential pressure switch mounted on the fender below the master cylinder. The switch has a shuttle valve that moves to the low pressure side of the switch if there is a leak in the front or rear brake circuits. When the shuttle moves, it grounds the wire attached to it and turns on the red brake light on the dash. The shuttle also stops fluid from flowing in the low pressure side of the switch. So it tells you that there is a leak/failure in the brake system which most people would notice without the light.. After 40 years the shuttle is most likely corroded and stuck. The red light is also turned on by the parking brake. The 280ZX master cylinder has a float switch that is triggered when the fluid level drops for some reason. That is it. Why bother with it?

http://www.ztherapy.com/ buy the video "Just SUs" You will be able to diagnose and repair any SU carb. Well worth the money for anyone new to SU carbs.

Check that your battery is good and that you may have pulled some wires loose. Also, check that the alternator is ok. Autozone etc can check the battery and alternator.

Hmmm. One bowel has fuel and the other bowel doesn't. I believe you have the answer.

Go here: http://forums.hybridz.org/topic/39435-help-what-brake-options-are-available-for-s30-z-cars/ type "14 inch" in Search this Topic window. Note: most of the popular disk upgrades do not improve braking performance. They actually reduce stopping performance and result in an unbalanced braking system. Many people regret doing the rear "disk upgrade" once they realize that it doesn't perform well and then they have to change other brake system components (domino effect) to make it work. Check out the brake balance calculations associated with various disk brake "upgrades" posted in the brake section. Hybridz has the most reliable information about Z modifications, but you have to dig it out.

What car and engine would help?

fuel level site plug fig. 4.

http://atlanticz.ca/zclub/techtips/suspension/swaybar/

http://corbeau.com/reclining-seats/gts-ii.html http://www.thezstore.com/page/TZS/PROD/classic08f09/40-7491

Autometer is the old standard for Z cars, but there are many new gauge brands that work better. The ideal solution would be to find a a fuel gauge that comes with a matched sending unit that could be retrofitted to a Z gas tank. My stock fuel gauge works perfectly so I left it alone.

100s of posts on this. search "Autometer fuel gauge" BTW it takes some doing to make the aftermarket fuel gauge read correctly. Also, Google "240z autometer fuel gauge" and you will find many write ups on fuel gauges: https://www.google.com/search?q=240z+autometer+fuel+gauge&client=ubuntu&hs=6lG&channel=fs&source=lnms&tbm=isch&sa=X&ved=0CAgQ_AUoAmoVChMIoJ3DsKz9yAIVkJaICh2YnAR2&biw=1344&bih=664

How are you going to use the car? Daily driver?

I always carry a wrench that fits the bleeders on the MC when road testing just for this situation. When the brakes start to seize from having the push rod too long you can unlock the brakes by opening the bleed screws on the MC to relieve the pressure so you can limp home to readjust the push rod in small increments. You may know this, but you do not have to disconnect the MC to adjust the push rod. There is enough flex in the hard lines to pull the MC out and push it aside to access the push rod.