Prius Brake pump running every 55 seconds ( Brazil)

Not certain if Spain and US vehicles are the same...

But keep a close eye on how long actuator goes before starting up to refill again... Once it gets down to every few seconds is when you aren't going to be able to safely drive it and that could take a while.

 

my son's 2005 pump ran every 9 seconds (ran 3 seconds then off for 6 seconds) for months before it finally started giving low pressure codes a couple weeks ago. Now it throws a code every now and then, but it's basically sitting while waiting to have the pump replaced.

 

Very interesting experiment and successful too! If I understand correctly this would be like using a "high mileage" oil in a leaky old engine? What is the result now a year later?

 

Since the difference in the 3 and 4 is related to water absorbency mostly then your change of fluid brings up a question. Was the good result from the change due to the brake fluid from dot 3 to dot 4? Or was it more a matter of flushing the old fluid out which perpaps contained contaminants, water, grit etc that could have affected the seals in the ABS actuator etc??

 

Maybe a little bit of both? Of course for how long? Many a great idea that doesn't last long on PriusChat doesn't get a follow up because most people are less excited to talk about being clever and then failing than they are about being clever and not failing.

 

It will last a day or two.

 

Do this and let us know if it stops your excessive actuator

 

Mine was running every 15 seconds so I did the same thing a few months ago. It immediately started making the same barking noise when applying the brakes my 2008 was when I got rid of it. Thoroughly flushed the brakes and it still did and eventually got worse so I had the pump and booster replaced since it was also leaking internally.

 

It won't.

 

A complete $150 flush will fix it for a day or two

 

If you aren’t losing brake fluid, it’s a mechanical issue and not a leak.

When was the last time the system was flushed (drain master cylinder reservoir then fill with fresh fluid and replace fluid to each wheel)? That should be done every few years, and contamination working its way into the lines can compromise line pressure.

You can do a flush and see if that solves the problem because it’s cheap and easy. If you will break open the system to replace brake system parts, you don’t bother bleeding/flushing the system first.

 

It has for me. Mine used to come on all the time and after performing the reset. It came on less.

 

Many factors can cause the apparent frequency of operation to decrease. Mine went from 3 s to 12 s (temporarily) without my doing anything at all except driving in warmer weather.

The one thing anybody can rule out as having an effect is the steps of the video, because it only reads stored DTCs.

 

Mine used to come on every 5th brake. After performing the reset, it only came on every 9th brake.

 

There's nothing in the ECU down there counting uses of the brake. It's just going to run the pump whenever enough fluid has left the accumulator that it needs pumping up again.

Some fluid does leave the accumulator every time you brake, but it's not a fixed amount. It depends on how hard you brake, and how far the caliper pistons return when you're done, and the rotor runout and whether the car is moving (if it is, runout increases the piston return), and so on. If there are any unbled bubbles in the system, they also increase the amount of fluid used each time you brake.

Which all goes to say that if you pay close attention over a longer period, you're likely to see "number of brake uses between pump runs" to be pretty variable, enough to be careful what you read into it. About the most we usually say is if the pump's running every few-to-several times you use the brake, that's about right.

But there's a separate issue about how often the pump runs if you're not using the brake. The pressure should hold up for hours then. If the pump is cycling, as in the title of this thread, every 55 seconds with nobody touching the brake, then nobody needs to do any counting of brake uses to spot the problem.

 

Mr. Chapman. If my actuator runs every 10 seconds most of the time would I be wise to just bite the bullet and install a new OEM actuator? Or just wait? Don't want to get stranded on a road trip someday 165,000 miles. Actuator seems to be run even more lately, but not sure how consistent it has been in this pattern.

 

The period between runs of the pump will be hours for a good actuator in good condition, when the brakes are not being used.

So the large number of PriusChat threads where people intently discuss the prognosis for a system that's pumping every 55 seconds or 20 seconds or 12 seconds or 3 seconds amount to a lot of words being spent trying to pin down the exact difference between really bad and plain awful, and it's kind of understandable to want to put off replacing an expensive part. But honestly, seeing any of those shortened periods tells you it's done for, and it's just a matter of scheduling when it'll be convenient to do the work. Maybe at 55 seconds you can treat the scheduling as a little less urgent than you can at 10 seconds, but that's what it all boils down to.