Constant Cycling Noise

yes, it is probably on it's way out, but could still last a long time

 

Every 20 to 30 seconds is pretty bad (though some people wait until it's every few seconds ). In a good one, the pressure holds up for hours if you're not using the brakes.

 

it is a confusing part. might be the tank, but i'm not sure. there might be a 10 year warranty, you can find out at toyota.com/owners, but i think you need a trouble code.

 

As well it should.

It's not a 'this' in Gen 3, it's a 'they', and the names usually throw people off.



The thing on top is known not only as the "booster" (as you see here) but also as the "actuator", the "master cylinder", and the "skid ECU" (which it includes).

The thing on the bottom is known as the "booster pump" and also as the "accumulator" (as you see here).

The thing on the bottom is what you are hearing when the pump runs. But the problem making it run so often can be either in it, or in the thing on top.

With a cheap mechanics' stethoscope, at 20 seconds between cycles, you can probably hear one or the other of them making a hissing sound during those 20 seconds. (For people who wait for it to cycle every few seconds, over a stethoscope it probably sounds like Niagara.)

 

If the car is under 150k miles and producing the right trouble code it may still be eligible for a free replacement. A more lenient 10 year unlimited mile program expired in August for hatchbacks and will expire in December for v wagons.

 

some here feel it should have been a safety recall

 

The duck noise can occur even when the system isn't close to failing. There was a firmware update that can reduce it, and going through the long-form bleed procedure can help.

But all that only matters if you have a system that isn't close to failure, and just is making the duck noise. In your case, at 20 to 30 second pump cycles, it's done for. Just get it replaced, and the new one won't quack.

 

Correct me if wrong as well, but I thought I also heard something about when replacing these two in pairs there are different versions even across same model years? I've been looking into buying these as spares but haven't pulled trigger until I'm 100% sure what I am looking for.

 

Yes. The best thing to do is look it up using your vin on a Toyota parts site. Wheel size and models like the v wagon use a different master cylinder. The real issue is if you buy used. Not only could you get a bad part but it could be the wrong part number. Used sellers often go with the housing number assuming they are all the same.

 

What's the mileage?