Flush: How much brake fluid to expel?

[michaelm101]

Vehicle (79 911CS) has been in storage 8 yrs & fluid is clean. I will be flushing with same color fluid.

Does anyone know approx how much fluid to expel/discard per wheel?

Thanx!

[HarryD]

I am not sure in your case but for my 1973 with manual brakes, for each caliper, I find that if I use about 200-250 ml, I will see a full color change as I swap between ATE 200 and ATE Blue.

[wildcat077]

I replaced my complete brake system over the Winter including four 996TT large calipers,23 mm master cylinder and new stainlees lines all around and having to bleed the clutch slave cylinder and i used up one full can of ATE blue fluid ...

I kept bleeding until everything came out blue,and i'm sure i would have had some leftover if i hadn't bled the system three times to be sure all the air was out !

Cheers !
phil

[michaelm101]

That helps. Thanx. I've got that Blue stuff, but want to do this first flush in 8yrs with the cheaper stuff ;-)...I already drained 4 of those little "mini" bleeder bottles from the right rear. Hoping that's enough as it all looks the same.

[steely]

I only used 1 - (liter?) so that works out the same too (250ml per). I went around the car like 5 or 6 times bleeding and refilling, never letting it get too low. I did not bleed my clutch slave cyl, on my 87.

I had even bought an extra can (ate blue) just in case but I never needed it, so I'll probably put that to use if I do a caliper re-build this coming winter.

[Flieger]

ATE Super Blue is pretty cheap. Why use sub-standard fluid if you are just going to flush it our right after for the good stuff? You will just use more fluid.

[wildcat077]

Michael,

I would flush out the clutch slave cylinder as well.It is a seperate system than the brakes although the fluid comes from the same reservoir.
The cylinder is on top of the gearbox,accessible from the l/h rear side of the car.

It's a little difficult for access but all you need is a 7 mm wrench and someone to depress the clutch pedal a few times !

Have fun !
Phil

[johnsjmc]

The 79 uses a cable clutch. The hydraulic mechanism didn,t appear until the G50 trans in 1987

[RWebb]

Originally Posted by Flieger

ATE Super Blue is pretty cheap. Why use sub-standard fluid if you are just going to flush it our right after for the good stuff? You will just use more fluid.

that would be 1st on my list also -- give the crummy stuff away, or use it in a daily low speed driver or something

if you cannot bear to use Ate Blue, then bleed until [a] the fluid changes from a turbid look to clear, or [b] until you've used up about what you're going to put in


or you could calc. the volume in the res. & tubes - a pointless exercise, so therefore fun

[rusnak]

I think it may help the discussion to differentiate between a brake "flush" and "bleed".

If you break the lines (open a connection), then you know you're going to need to bleed the mc circuit that you opened, at minimum. So you might bleed that circuit, and flush the other one.

I find bleeding the front circuit to sometimes be problematic on my 911, so when I go to bleed the fronts, I usually use a small can of the cheap stuff because I have gone through half a can of ATE Super Blue, only to have to re-order another can before putting the car into service, then having almost a full can left over. Sometimes you get a good bleed right away, and sometimes the air bubbles just don't want to come out unless you resort to pedal bleeding.

A simple flush will be straight good stuff, but due to mixing of the fluids, I would keep flushing probably half again as much after you see the color change.

[Bill Verburg]

You'll save some time if you lower the reservoir level w/ a turkey baster before opening up the calipers. Just don't let it run dry