Dan Wendling

What is the brake fluid volume for a 2010 GS (same as Z06 I think)? I want to purge my OEM fluid and replace it with Castrol SRF but have no idea how much to buy? Expensive so, need to only buy what I need.

Jaymz

When ever I have done a flush I have used almost a full bottle. So I would buy two bottles so you will have some to bleed the front calipers when you need to.

Dan Wendling

Anything special that needs to be done to flush the system completely? What about the ABS, do I need a TechII to to it correctly?

sothpaw2

A tech II will do the job but instead what I have done is to go for a few drives after the 4 wheel-flush and then get into the abs multiple times. Then I re-bleed at the 4 wheels. With a 2010 this shouldn't be such a big deal anyway as your dot3 is at least relatively fresh. When it has not been changed in 5 years, even a little remaining is a problem.

Dan Wendling

If I don't use a Tech II it seems that I would need to do two complete flushes to move from OEM to SRF fluid. Aren't the ABS valves fairly far from the calibers?

I have heard that even a small amount of the OEM fluid will dramatically lower the wet temp performance of the SRF.

Bill Dearborn

I haven't used the SRF but have used plenty of other fluids with a high dry boiling point. When I bleed I don't worry about the small amount of old DOT 3 in the BPMV and over the last 20 years of autocrossing and doing track events I have only had one occurrence where the brake fluid boiled and that was due to buying a bottle of fluid that hadn't been sealed correctly. I took a chance on it and that chance didn't work out.

The reason for doing the Tech 2 bleed is to remove any air that might be trapped in the BPMV. When you first start the engine and move the car the ABS system does a self test and runs the solenoids and pump motor in the BPMV which probably moves the fluid around. I used to think that doing what sothpaw2 does would purge air from the BPMV but I have come to doubt anything but a Tech 2 bleed will get the air out. The reason for that is neither the self test or activating ABS is done with an open system. If the system isn't open then there is very little movement of the fluid inside the plumbing thus very little movement of any air. With the Tech 2 the valves are opened into an open system while it is being pressure bled so the fluid and any air trapped in it flows out of the BPMV, through the plumbing and past the bleeder screws.

Just make sure you do not get air into the BPMV which can happen if you let the master cylinder reservoir go dry or open the system where it is attached to the BPMV. That way you won't need to do a Tech 2 bleed.

Bill