Brake Booster Pump Failed While Parked, 2010 LX570 (Resolved, Dead Battery)

[terrapin]

I am stuck at a campground near Silver City, NM. I have been here for a few days and yesterday I moved my trailer to another campsite. Everything was fine, no dash lights or any warning. Up to that point the brakes have been fine.

After I moved the trailer, I parked my vehicle and left it for a few hours. When I went to open the tailgate and there was absolutely no power. That was when I noticed a buzzing sound from under the hood. It appeared that the brake booster pump had been running non-stop for at least four hours. I disconnected the battery and let it sit overnight.

This morning I reconnected the battery and the booster pump buzzed and then wound down. I think the battery is completely dead. I connected my battery booster and I got some dash lights, but the motor would not even turn.

I'm having it towed to the dealer in Silver City on Tuesday (which I am dreading). Any ideas or suggestions? I only have basic tools and no diagnostic equipment with me.

Nothing had been done to the brakes recently. I am using a Redarc brake controller and had no problems with it. Also, no degradation of the brakes up until this point. FWIW I had also "exercised" 4-lo with no problems about an hour before the problem occurred. I do not see any obvious signs of rodent damage.

FYI, Toyota suggests that the pump be replaced periodically!!!

Brake Booster Pump Assembly with Accumulator #47070-60060 | Autoparts.toyota.com

Ensure optimal brake performance in your Toyota with our Brake Booster Pump Assembly with Accumulator. Shop Genuine Toyota parts now!

autoparts.toyota.com

 

[bloc]

If the pump was running non-stop I'd suspect whatever controls it electronically, not the pump itself. Somehow the EWD doesn't show the pump wiring itself, only the larger ABS/VSC stuff.

The controller is mounted directly to the master cylinder..

Search for "Solenoid, Master Cylinder" to see what comes up in the parts system as the leads on your part plugging into. You'll need to get the number off yours though, there are a bunch of trim/build date splits. Don't take this as a quote but 47217-60230 will get you into the ballpark if you want to research some pictures.

 

[Sandroad]

A couple random and probably irrelevant thoughts…

There have been posts on here about rodent damage while parked at a campsite and they work fast.

A dead/dying battery can cause weird electrical effects. Is there any chance your battery died from something other than a failed booster?

Can you get someone else in the campground to jumpstart it and see what happens?

I would have thought brake failure would have lit up the dash.

And, note that it’s just that dealer being a parts pusher who recommends regular replacement. It’s not Toyota.

 

[terrapin]

FYI, Toyota suggests that the pump be replaced periodically!!!

And, note that it’s just that dealer being a parts pusher who recommends regular replacement. It’s not Toyota.

Ha, you are right. I randomly checked some other parts (steering column, instrument panel, o-rings, etc.) and they all say to replace periodically.

 

[terrapin]

Turns out that my approximately one-year old Toyota battery was completely dead. Even AAA could not get a peep out of it with their giant battery booster.

In 50 years of driving I have never had a battery die this suddenly and completely. I had just towed my trailer to another spot in the same campground and the truck sat for approximately four hours before I noticed it was dead. No dash lights or starter, just that buzz under the hood.

All I can think of is that my headlights did not turn off due to some odd combination of turning off the vehicle with the tailgate and other doors open. My trailer backup camera requires that the headlights be on to activate (not auto). I've used this setup for at least four years and dozens of trips with no problems.

@Sandroad was correct about a dead battery causing weird electrical effects. Attached is a video of the sound the brake booster was making. Since I was camping, I totally panicked and had my truck towed to the nearest dealer and also had AAA move my trailer to another site where I could stay for a week or longer. Unfortunately, the small town dealer did not have my Toyota battery in stock and I did not want to wait another two days before they could get one and then start troubleshooting. I was already adding up the dollars in my head to replace the brake booster or worse.

All in all, between having to rent a vehicle, use two tow trucks, and pay an exorbitant markup on a parts-store battery this was an expensive mistake!

 

[Sandroad]

Turns out that my approximately one-year old Toyota battery was completely dead. Even AAA could not get a peep out of it with their giant battery booster.

In 50 years of driving I have never had a battery die this suddenly and completely. I had just towed my trailer to another spot in the same campground and the truck sat for approximately four hours before I noticed it was dead. No dash lights or starter, just that buzz under the hood.

All I can think of is that my headlights did not turn off due to some odd combination of turning off the vehicle with the tailgate and other doors open. My trailer backup camera requires that the headlights be on to activate (not auto). I've used this setup for at least four years and dozens of trips with no problems.

@Sandroad was correct about a dead battery causing weird electrical effects. Attached is a video of the sound the brake booster was making. Since I was camping, I totally panicked and had my truck towed to the nearest dealer and also had AAA move my trailer to another site where I could stay for a week or longer. Unfortunately, the small town dealer did not have my Toyota battery in stock and I did not want to wait another two days before they could get one and then start troubleshooting. I was already adding up the dollars in my head to replace the brake booster or worse.

All in all, between having to rent a vehicle and pay an exorbitant markup on a parts-store battery this was an expensive mistake!

I’m glad you’re back on the road. Could have been an internal battery problem.

 

[FrazzledHunter]

Reiterating @Sandroad said about electrical effects following a dead battery. No kidding, no joke. I know the feeling of having a dead LC when you're out in the field.
REF: Error code P0121 brake override malfunction solved in the field - https://forum.ih8mud.com/threads/error-code-p0121-brake-override-malfunction-solved-in-the-field.1321119/post-15129436