How to Bench Bleed a Master Cylinder in a Saturn Ion

The short-lived Saturn Ion premiered in 2003 to replace Saturn's popular S-series. When you decide to change the brake master cylinder in your Saturn Ion, it's smart to bench bleed the new one to ensure there isn't any air in the system. You can bench bleed your new master cylinder in about 10 minutes; these directions apply a Saturn Ion from any year.

Difficulty: Moderate

Instructions

Things You'll Need:

• Replacement master cylinder (varies by model year and engine type)
• Bench bleed kit (may come with the cylinder)
• Bench vise or clamp-on vise
• Brake fluid
• Phillips head screwdriver

1. Remove your old master cylinder before you bench bleed and install the new one. The brake master cylinder of a Saturn Ion sits prominently at the rear of the engine compartment between the engine and battery.

2. Set your new Saturn Ion master cylinder in a bench vise; if you don't have a bench vise, you can use a clamp-on vise and an old table. Clamp the cylinder firmly into place, making sure that it's level. Open up the bench bleed kit and have it close by.

3. Put the old reservoir into the new master cylinder, if you're reusing it. Be sure you clean and dry off the reservoir completely, since brake fluid absorbs water and can damage your brake system. Then, install it into the top of the new master cylinder. If a reservoir came with your new Saturn Ion master cylinder, you can skip this step.

4. Find the two fittings that came with your bleeder kit. Thread them onto the outlets located on the side of the cylinder; they're both on the same side and you'll see the threads in the outlet holes. Take the two lengths of hose that came with your kit and insert them into the fittings and bend the hoses up, so they're aimed into the fluid reservoir.

5. Cut the hoses if necessary so they stick point-down into the reservoir and extend about halfway into it. Use a clip to secure the tubes to the side of the reservoir and keep them in place. You don't want them to come loose and allow air into the system or spray brake fluid around.

6. Fill the Saturn Ion's reservoir with fresh brake fluid. Pour enough into the reservoir to fill it just shy of the maximum fill line. The plastic hoses will extend down into the fluid, creating a miniature hydraulic system.

7. Pump the piston on the brake master cylinder to move the fluid through the unit and into the hoses. Use a Phillips screwdriver to do this by putting the screwdriver into the cylinder and pushing it firmly against the piston to start pumping.

8. Watch for air bubbles coming out of the hoses and into the fluid in the reservoir. Keep pumping until all the air is out of the cylinder and you don't see any more bubbles. Consider buying clear hoses if the ones that come with your kit are black, so you can see the air bubbles better.

9. Leave the two hoses in the reservoir and slowly remove the cylinder from the vise. You can now install the primed master cylinder into your Saturn Ion.

Tips & Warnings

• Brake fluid can damage the paint on your Saturn Ion, so try not to get any on it. If you do, clean it up right away with a towel, soap and water.
• Don't let the reservoir run dry, since pumping the master cylinder without brake fluid will put air into the system and you'll have to start over. It's unlikely that the fluid will get low if you put the proper amount of brake fluid in to begin with.