67King

First time I bled the brakes on mine, I didn't realize there were two bleeder screws per caliper. ANy chance you are only bleeding the outside screw?

Cloud9...68

Nope - bled both the inside and outside bleed screw on each caliper simultaneously. They both flowed at similar rates on each caliper, and had roughly equivalent amounts of initial bubbles.

gpr8er

just wondering....all the calipers are installed so the bleeders are on the top, right?

Cloud9...68

Yes, that's correct.

I remember another guy, I think from Australia, who was fighting a mysterious spongy brake pedal problem for a long time as well, but I don't remember the resolution, if any. If somebody remembers this thread, could you please send me a link? Thanks.

jerome951

Try bleeding the outer caliper half alone, then the inner. Also lightly tap the caliper w/ a soft mallet while bleeding.

Also give the brake pedal a few, firm strokes while the Motiv is attached. Sometimes you need fast flow to force out bubbles from high spots in the lines.

Reimu

If I leave a broomstick on my brake pedal for a while and drive it the pedal is much firmer. Unfortunately this fades back to the old extended travel after around a day or so.

67King

Alright, I'd say it is time for the kitchen sink.

First, what does your reservoir look like? does it have a film like thing in it? If it isn't very clean, then when you put new fluid in it, it can break that stuff loose and that'll mess up your master cylinder. Ask me how I know.

If it isn't clean, get a new reservoir. They aren't too expensive, $100 or so.

Regardless of if it is clean or not, get a couple of big bottles of cheap brake fluid. FIll the Motive. I mean FILL it. Pressurize it, go put some drain tubes on the RR caliper, crack the bleeders, then get in the car and pump the pedal with your foot. You can move a LOT more fluid that way than just with the Motive. Repeat for all calipers. If there is any air in the system that is being stubborn, the Motive itself won't do a good job of flushing out them, as the fluid can't move quickly enough.

Once you do this, you can reuse the fluid, and do it for all four calipers. If air in the system is the problem, this should take care of it. But you have GOT to use the pedal to move the fluid, not just the motive. If that doesn't take care of your problem, you may have a bad master cylinder.

Once done, take a turkey baster out and remove as much fluid as you can from the reservoir, then just do a regular flush with a good fluid.

Cloud9...68

Thanks for all the tips.

67King - I just put two 500 ml bottles of expensive Wilwood Series 600 fluid in the system. I should be able to squeeze most of it out (using the Motive without any fluid in it) and reuse it, right? How do I minimize the risk of introducing air into the system, or should I not worry about that, and just let the flush with the cheap fluid as you recommend take care of that?

I thoroughly drained and wiped out the inside of the reservoir before installing the new MC, and it was quite clean to begin with, so I don't think the reservoir was introducing any foreign matter into the system.

Your technique of using cheap fluid simultaneously with the Motive and with my foot on the pedal sounds good, as I do suspect my problem is air trapped in the system somewhere. Should I keep my foot on the brake while bleeding each caliper? Maybe I'll ask an assistant to tap on the caliper, as Jerome951 suggests, while bleeding each one. Thanks again.

67King

I'll shoot you a PM and find a way to get you some fluid at a break. I sell Millers Oils products. Their brake fluid is the same and the same as Motul and the same as STop Tech, etc, etc, etc. All of them outsource it from the same place.

Just flush out the cheap stuff. Get a pair of Genesis bleeder bottles from Apex or Discovery or somebody. Hook up them, they won't let air back in. You will need to PUMP the brake pedal, not press it. Just like the old school way of bleeding brakes.......you are only using the Motive to ensure that you never run out of fluid while pumping the pedal.

Cloud9...68

Question - Is it possible I have some air trapped in the ABS plumbing? If so, would there be any benefit to doing some stops hard enough to engage the ABS before I start the bleeding process? If so, should I do this right before I start bleeding the brakes, or can I do it beforehand? The reason I ask as that the roads in Austin are damp right now, so it would be easy to activate the ABS. Thanks.

Eric_Oz_S2

I think activating the abs is a good idea before you try re-bleeding. The only other cause I can think of is a fault in one of the flexible lines (swelling).

Cloud9...68

Eric,

Thanks; as soon as I finish the more pressing car repair project I'm currently in the middle of, I'll wait for another drizzly day, and take the 968 out to activate the ABS a few times before I start the re-bleeding operation.

I've heard it from several sources, so there must be some validity to it, but how exactly is it beneficial to activate the ABS before bleeding the brakes? Obviously, my pedal is mushy when the ABS is not engaged, including sitting still without the engine running. If there's air trapped somewhere in the ABS system, how does that contribute to a mushy pedal under non-ABS use conditions? Thanks.