Steve49841

I want to flush the old brake fluid out of the system on my C5 Z06 and switch to Motul for an up coming HPDE at Mid Ohio. The question is How much Motul will I need to buy to replace the old dirty stuff. The service manager at our local Chevy dealership said a gallon. Can that be right?

Aardwolf

You can watch the fluid change color so then you know each caliper has the fresh fluid. I have flushed mine and used two pints, with very little left. If you are going to buy fluid it might be best to stick with just one type. So buy enough to last awhile. Do you intend to bleed the brakes often? Three pints will leave enough with my C4 to flush the system and have enough to spot bleed here and there. If you are going to stick with one type of fluid, buy a bunch. I use three pints per year at the above rate.

MungoZ06

AIR, it took about two bottles of Motul and I had the shop do the Tech II ABS flush to get it all.
Dealership is full of brake fluid!
Some use ATE Blue/Gold ... alternate to do the color change thing ...
I' bought a case of Motul (12 bottles) in April 2004; gone thru 9 so far; figure what I have will last the rest of this year.

Steve49841

When I change to Motul that will be all I use in the future, and I have a local supplier, so getting it is no problem. Because I'm new to HPDE I really don't know how often I will have to spot bleed yet but I want to be prepared. I did a NASA event at Grattan a couple of weeks ago and the brakes did fine but the fluid is nasty looking and I want to get it changed to a high temp to be safe. Are you guys having to spot bleed hi temp synthetic brake fluid at the track?

AU N EGL

Figure 2 full bottles.

One full bottle to flush each line and caliper, and most of the second bottle to fill.

Just because you see the fluid change color, make sure you 'tap' each claper to brake free any bubbles or old fluid that may be stuck in there.

Once you do all four corners, put your wheels back on and go for a drive and make sure the brakes work. If they do, hit the brakes hard a few times, then back to the garage to bleed all four calipers again.

Steve49841

Thanks, looks like a couple of bottles should do it. We are going to use one of those pressure bleeders so hopefully that will take care of trapped bubbles etc but the re-bleed is still a good idea.

AU N EGL

Defintly the pressure bleeder, but still tap on the caliper lightly.

davidfarmer

for those "little" bottles, I like to drain the resevoir with a syringe, then:

1 bottle to flush, 1 bottle to bleed, and another bottle to top off the system and save. So 3 bottles. For big bottles like Valvoline Synpower, you can do it with 1.5 bottles, maybe even just one.

FasterIsBetter

While you are at it, do Ranger's clutch fluid routine as well. Use your Motul brake fluid in there as well. Get all the old fluid out of the reservoir, put in fresh Motul. Pump the clutch pedal 20 to 30 times, remove the fluid from the reservior and replace with fresh fluid. Repeat that a couple of times until the fluid stays clear. Motul will mix fine with existing DOT 3 or 4 fluid in your clutch system.

In terms of how often to bleed the brakes, I usually do it before each track event. Be sure to remove as much of the old fluid as you can from the brake reservoir and put in fresh fluid before bleeding the system.

Prankster

I just did it this weekend, and used 2 full bottles..but I still needed a third bottle to top it off. It was pretty close, but I needed just a little from the 3rd bottle.



pkstr

R Mackow

What's a pressure bleeder? I have been using an old laboratory vacuum pump to draw fluid out. If you put a bottle in-line(rubber lab cork w/an inlet and out let tube), the vacuum is maintained and fluid drops out in the bottle. I also use the same setup to suck the master cyl. and clutch reserviors. Are there any issues in bleeding fluid under vacuum?