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Discussion Starter · #1 ·
I recently did a full brake fluid flush and put a new OEM brake pads. I did this on numbers of other cars for years, so not new to it. What new is I used a MOTIVE pressure bleeder for the first time https://www.amazon.com/gp/product/B0002KM5L0/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

I did everything per instructions: rear right, left, then front.

Now my brakes don't behave. The symptoms are pretty consistent. When I use the brakes - the first application is great - pedal is firm, brakes work as supposed to. I can do emergency stop from speed to 0 in not time. Everything's great.

However if I lift brake pedal, wait a second, then use it again, then lift for another second then use it again (like when you stop for a stop sign and try to pull closer to see intersection better...

On a third low speed brakes application - they don't grip too well. Pedal gets firm, and the car keeps (slow) moving until I push the pedal REALLY hard. Much harder than usual.

What the hell is going on? Any ideas? I's stop at a dealer, but have no confidence in them...
 

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Did you do the wet or dry method? Sounds like there is air in the system. There's always that danger using the dry method if you don't keep a close eye on the level.
I use dry, but added a valve between the bleeder and cap so I could easily remove the cap (without loosing pressure or scattering fluid) to add fluid.

I'd buy another liter and re-bleed. Maybe have someone pump the pedal while bleeding the rear to purge any air in the MC.
 

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Discussion Starter · #3 ·
Did you do the wet or dry method? Sounds like there is air in the system. There's always that danger using the dry method if you don't keep a close eye on the level.
I use dry, but added a valve between the bleeder and cap so I could easily remove the cap (without loosing pressure or scattering fluid) to add fluid.

I'd buy another liter and re-bleed. Maybe have someone pump the pedal while bleeding the rear to purge any air in the MC.
I put fluid into the vacuum bleeder. Is that "wet"?

I'm pretty sure I kept eye on the level, but I was always wandering what happens to the air that was originally in the vacuum bleeder hose...
 

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That's the wet method. Any air in the bleeder/hose would go into the top of reservoir. Wet or dry, as long as there's plenty of fluid at the bottom - no problem. With either method, you start with a full (or close) reservoir before connecting the bleeder. Wet method - you put 1 liter or more in the bleeder and you only need to make sure it you don't run it out of fluid. Dry involves manually topping-up the reservoir - so more danger of running dry. But no cleanup later.

How much pressure do you pump it up to?

Still - since something is definitely wrong, I'd get another liter and do over. Sounds like air trapped somewhere. Also, see if the level in the reservoir has gone down. When you changed pads you compressed the pistons and they need to re-fill fully by pumping the brakes.
 

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I've used vacuum dozens of times, and other than 1 time where I learned that vacuum WILL suck air well before fluid is at the bottom of the reservoir (call it the tornado effect), never an issue. And I bet that's probably what happened to you. Once you introduce air into the system, it's a b*tch to get rid of. First of all, you'll need to activate the ABS pump, PLUS you'll have to do a pressure bleed for both the primary and secondary circuits, to get rid of all bubbles. What I use when I can is a bottle that maintains the reservoir full all the time, and just finish off the entire 32-oz until level is at the top. Job done. If the reservoir is deep into the firewall and can't fit the bottle (upside down), then I only suck to the minimum mark, then fill up to the brim and repeat. Next time you shouldn't have any issues, but I'd let a pro do the bleed now because I think only a PIWIS can activate both the pistons and the secondary circuit valves (which require a special sequence). Good luck.
 

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Discussion Starter · #6 ·
The reservoir never went empty... Ok, I guess, time to go to the dealer. They'll probably have opening sometimes in September...
 
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