*This might need to be moved to [TECH], apologies if that is the case*

Last weekend while checking fluids etc, I noticed the brake fluid has gone a shade of brown and cloudy (looks like an old chemistry experiment with something clearly suspended in fluid). Can someone share a link to a good write up on how to properly flush the whole system? I will have access to a Tech 2, lift, tools, etc so I want to do this right.

Thanks in advance,

 

While I don't have a write up, for what you want to do I highly recommend buying the Motive Products pressure bleeding kit which is ideal for flushing cars.

You can get a whole kit with the proper cap for your Corvette for under a hundred bucks. You can fill the pressure pot with 2 quarts of new fluid and flush/bleed the whole system in probably under 10 minutes.

If you want to cycle your EBCM with the Tech 2 that's even better.

 

The Motive Products pressure bleeder will work well for doing a brake flush, IF you want to go this way, getthe bleeder kit p/n 0118. This kit has a metal cap instead of the plastic cap. When I use mine, I don't put any fluid into the bottle. I fill the reservoir and attach the cap then pump air pressure to about 10-15 psi. Then open each bleed valve (one at a time!) until fresh-colored fluid starts to come out. Keep an eye on the amount of fluid in the reservoir. You will have to release the air pressure and remove the cap to add more fluid. DON'T let the master reservoir empty!! The bleed sequence is RR, LF, LR, and RF.

A easier (and less costly) way is to remove each stock bleed valve and install "Speed Bleeders" on each of the calipers. These are bleed valves with a small spring and check ball that allows you to open the screw about 1/4 to 1/2 turn. No fluid will come out until you push down on the brake pedal. Use the same sequence one at a time. When fresh fluid comes out, just tighten the bleed screw. Keep an eye on the fluid level in the reservoir and re-fill as needed. For either method, get one of the small plastic bags with a length of hose that you attach to the bleed valve to collect the old fluid. They are cheap and are a big help in keeping everything clean and dry

Use a good grade of DOT3 or DOT4 fluid. For DOT3, Valvoline is a good choice or even the Ford HD Motorsports fluid. MOTUL or ATE TYP200 are good DOT4 fluids. You will need to get the car jacked up and remove the wheels to get access to the bleed screws. Fluid won't come out too fast so so the chances are that the ABS won't be affected with a air pocket. Go slow and the EBCM won't be a problem.

 

Before you start bleeding, take a syringe or clean turkey baster and suck the old fluid out of the master and replace with new. Use DOT4, it is compatible with DOT3 but has a higher boiling point. ATE TYP200 is good for a cheap price. Amazon sells it.
As what c4cruiser said, don't put brake fluid in the motive bleeder. Just use it to pressurize the master. Much easier to do it like this then cleaning the brake fluid out of the motive bleeder when you're done. As long as you make sure you keep the brake fluid topped off while you're bleeding and don't let the master run dry, you shouldn't need a Tech tool.

 

 

One thing I always caution though about using speed bleeders or the old school pump and release method is it's very easy to trash a master cylinder that way. I've done it two or three times myself over the years.

When you bleed that way and you don't short stroke the pedal you push the master cylinder seals through corrosion in the bore of the MC that it doesn't normally travel through. I know this won't happen every time but it is a gamble that is taken.

I have since vowed to try and not push a brake pedal all the way to the floor because replacing master cylinders is a shitty job. The beauty of the pressure bleed is it eliminates that pumping action.

If using the pressure pot system, If I'm doing a flush I will fill the bottle. It's just easier for me. If I'm just bleeding by all means you can leave the bottle empty and just pressurize a full MC.

 

Cleaning out the pressure pot and hose is not hard. Geesh.

 

It's even easier not to clean it at all.

 

Keep in mind, folks, that when you use the Motive bleeder to dispense brake fluid, and unscrew the cap from the m/c, it IS possible for residual fluid to drip from the cap/supply line, and ruin your car's paint......

 

Because I track the car, I flush the brakes at least every other year with ATE Typ 200 DOT 4 fluid which has a relatively high wet boiling point compared to DOT 3.

Between 2009 and 2016 I flushed the brakes 5 times with the car on jack stands, wheels on, and using my Motive Products bleeder. As noted above, you have to be very careful because the brake fluid in the Motive Products unit is under pressure when pumped up. Brake fluid on your exterior paint can ruin your day, especially if you fail to notice a small drop somewhere. Also because the fluid in the Motive Products unit is under pressure by pumping ambient (moist?) air into the unit, the new brake fluid may absorb a tiny amount of the moisture in that air. That is why more expensive units for pressure bleeding use a bladder for the brake fluid under pressure.

In 2016 I switched to speed bleeders sourced via Summit Racing and have flushed twice so far using those. I find the speed bleeders are easier to use with less risk of paint damage.

Ahead of time get the bleeders, plastic jar for flushed fluid and appropriate hose to go from the bleeder to the jar. I put a small weight on the end in the receiving jar to keep the hose from slipping out and spewing brake fluid.

I measure the amount of fluid flushed at each corner, flushing a little less that the full Liter of Typ 200 in total for all four corners. You have to keep an eye on the master cylinder fluid level of course. My notes indicate that it takes about 20 brake pedal pumps rear, 15 pumps front each corner. Plus 5 more maybe each location.

Factory Service Manual order is RR; LF; LR; RF.

 

Moved to C5 Tech.