XenonZcar.com - Bleeding your Z31 brake system the right way
Any time you remove a part of you brake system (Master cylinder, Caliper) or the system develops a leak, or if the fluid in the master cylinder runs low, Air will enter the system. To remove this air the system must be bleed. If the Master cylinder was removed or fluid in the master cylinder runs low a complete bleeding of the system will be needed. If just a caliper or line was removed then just that brake will need to be bled.
- Large Container of dot3 brake fluid
- A length of 3/16” Rubber Tubing
- Empty Clear container ( Glass or plastic)
- 8mm line wrench
- 1 Good Assistant
Things Needed
- Left Rear
- Right Rear
- Right Front
- Left Front
Order of wheels to bleed
Process to Bleed brake system
First apply brake with the car off a few times to remove the Vacuum built up in the booster. The brake pedal should feel hard at this point. Next, check that the master cylinder is full of fluid and it should be maintained at least half full during the entire process.
(Note: If the fluid becomes low at any time during the process, you must start over again as air will again be entering the system.)
(Caution: Do not mix different types of fluid or reuse old fluid as is can damage you brake system components)
When bleeding the whole system, start with the Left Rear wheel. This is the furthest from the master cylinder.
Loosen the bleeder valve to break it loose and then snug it so it is easy to open and close quickly. Place one end of your tubing over the end of the bleeder valve and submerge the other end into the container you have with some new fluid in it.
Now have your assistant pump the brakes to build pressure in the system and on the last pump have them hold pressure on the pedal.
With pressure on the pedal, slowly open the bleeder valve just enough to allow fluid to leave the valve. Watch for air bubbles to leave the end of the tube in the container.
When the fluid slows, or the pedal is on the floor, Close the valve and repeat until no more air is seen leaving the tube.
Tighten the bleeder valve to 6.5 ft lbs and move on to the next wheel in the above order.
Be sure to check the level of fluid in the master cylinder often.