Bleeding brakes Question

I have never had that issue with my Motive

 

Nope. Think about it. Assuming you live in a place with normal gravity, any fluid will be at the bottom of the reservoir and any air will be at the top. Assuming you don't drain the reservoir down to the point where it holds less fluid than the feed line from your bleeder bottle and assuming your bleeder container holds a good bit of fluid, the fluid will fall to the bottom of the reservoir as it flows out of the bleeder container, through the feed line, and into the top of the brake system reservoir. As you might expect, the air will be at the top and all the fluid will immediately fall toward the center of the earth, since the density of air is less than that of brake fluid.

So, when you open the bleeder screw down at the caliper, fluid flows through the system and is replenished from your bleeder container and a big bubble of air remains in reservoir, but it is at the top, not down near the bottom where it's connected to the brake lines and ultimately to the calipers. So, only fluid enters the lines. Assuming you stop before you empty the pressure bleeder container, you're OK.

Some people apparently just top off the reservoir and use the pressure bleeder as a source for pressure, not fluid. The idea is to keep the tool clean but that doesn't make a lot of sense to me. Anyway, in that case, you have to use caution to stop before you empty the car's fluid reservoir. Either way works fine.

Of course, if and when gravity fails, all bets are off.

 

Word of warning to you with this system, be very careful with the cap to reservoir interface. I was unable to get a solid connection. Motive recommended wrapping the threads in teflon tape to get a tighter fit. In the end I was never able to get a solid connection. If I had filled the Motive tank with brake fluid it would have spilled fluid all over the car. Good luck! YMMV.

I successfully used this system on an Elise, Spec Miata and Z28. Their European cap just didn't fit my 360.

Jeff

 

Jeffg11, did you have the billet cap or plastic? Even those the euro plastic cap isn't the right size, it holds the pressure I need.

I don't take any fluid out before bleeding... just fill up the motive, pressurize, and go.

 

And, of course, everybody knows to bleed the master cylinder after finishing with the calipers.
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Don't really have to if you never let air in the system... It is a good thing to do, and I've had to do it a couple times, but a pain since it's behind the front trunk carpet and vapor thing.

I hear the billet cap doesn't work, and the plastic cap has deeper threads so even though it's incorrect it works.

 

I'd highly recommend this product. Comes with sufficient reservoir capacity to do the whole system flush with a single fill and has the correct cap also.....

Linky:- Sealey
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Some good advice here.
One more piece of advice I would like to add. Make sure that you do a trial fit of everything before adding brake fluid to the bleeder canister.
Screw the cap for the bleeder on the car and pressurize the system, then leave it for a while to make sure that it maintains the pressure. You don't want to find a leak AFTER the brake fluid is added!

 

When using the Motive pressurized brake bleeder, I found that if suspend the resrevoir above the fluid reservoir, it seems to work better. And, do make sure to pressure test the set up before you fill with brake fluid.

One more thing .... the instructions for the Motive state to pressurize to 10 psi. Although you may be tempted to think that if 10 psi is good, then 20 psi would be better to gain more rapid flow when you open the bleed screws, don't do that. Ask me how I know this.

Steve

 

I have a motive pressure bleeder that I use to flush the brake system. I have always used my vacuum bleeder (connected to a compressor) to drain the old fluid out of the master cylinder. One should then fill the master with fresh fluid before connecting the Motive to the M/C. As stated earlier, this method prevents the introduction of air, therefore a M/C bleed shouldn't be necessary. While you can get it, Ate super blue at one flush and amber at the next would give you a visual of complete change of fluid.

 

1+3/4 Inch on your reservoir or on kit winging it's way to you?

My car is 360 euro model but I suspect it's the same throughout the globe. The threads on the reservoir measure circa 43.2 mm (difficult to get the calipers on cleanly). The inner diameter of the cap that fits correctly is 42mm (approx 1.65 inches).

 

Sounds like you have the wrong cap. It's "do-able" the way you describe but it's not really a great solution. Brake fluid under pressure with a make shift connection and fresh Ferrari paintwork have reasonable potential for calamity.

What tends to happen is that there will be a slight air leak around your connection. As the air escapes (which is not a problem for your brake system) it's replaced with fluid and gradually over several minutes the reservoir air will be entirely replaced with fluid until such time as it's fluid, not air, that's escaping.

Better to get the 42mm cap if you can.