Power brake issue, 2019 TRD Sport

Ray Haefy

Member
I've never owned a vehicle with the Push - Start button. Engine starting requires that I step on the brake pedal prior to pressing the start button. Maybe all 2019's are that way. If I allow the vehicle to sit unused for more than 2 days the brake pedal is hard to push ( as in with no power brake assist. ) Once started the power brake assist is back and will remain available unless the vehicle sits un-used for more than 2 days. After 2 days the booster is empty of vacuum therefore the brake pedal is hard to push. After pressing the brake pedal and then the start button I see a message on the display that reminds me to press the brake pedal, which I then do by pressing the brake pedal harder. Its not so hard that I have to struggle to press it, rather it is different then when power assist is available. If I wait just a moment a message appears saying there is a brake malfunction.

Tech support doesn't seem too concerned about the power brake booster possibly leaking. The dealer service department is more concerned about the fact that I can't start the engine.

I spent the largest part of my working career as an auto mechanic and have diagnosed a lot of brake problems but cars didn't have Push - Start buttons then. Usually, when a power booster went bad there would be a hissing noise under the dash or the engine would run rough when the pedal was pushed. But, mostly, a vehicle would hold its power brake booster vacuum for weeks, if not longer. My 2014 RAV4 will hold at least 5 assisted brake applications for 10 days, maybe more, before starting the engine. It doesn't have Push - Start.

My concern is that the booster may have a leaking diaphragm.

Anyone have any ideas or can tell me if their vehicles booster holds vacuum.
 
Good news! The only thing I've done is after parking the truck for the day several times I would pull up on the brake pedal with the toe of my shoe. I never felt it move or anything so I quit doing it. But, today my suspicion that it was getting better came true. After not using the truck for three days I got in and found that it had 4 1/2 power assisted applications available without starting the engine. Now that's more like it. Who knows but maybe the valving in the booster just didn't seal properly until I pulled the pedal up.
 
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