Truck randomly dies when braking.

[who done it]

When driving the truck, at any speed, the truck will randomly die when braking.

Sometimes just the electrics will cut off, but engine will continue to run.

Sometimes the entire vehicle will die.

She turns right back on, and I seem to have somewhat gotten to the solution. I've checked the vacuum lines and ground lines. Check the aftermarket radio.

Now when the truck is idling and I press the brakes it idles just fine. However, if I put the truck into Drive / Reverse and press the brake the idle drops down to 500 and below and the truck starts to run rough. Once off the brake it idles back at normal. In neutral / park there is no effect when pressing the brake.

Do you think my booster / booster diaphram is leaking or can it be something else that someone here may have a bit more experience with?

Truck is a 2006 4Runner V6 4WD.

 

[JLTD]

It does sound like a vacuum leak and/or electrical short.

Have you checked the wires running to the brake lights? I've seen several (no T4R) vehicles that had corrosion around the tail lights which shorted when brakes were applied.

 

[AuSeeker]

I'm not sure what you're issue could be...but I can tell you that 4th Gen T4Rs don't have a vacuum brake booster system, therefore it can't be a vacuum leak from the brake booster.

The brake booster/ABS system works off a small electric motor that operates a small pump and the pressure is stored in an accumulator, all of this assembly in attached to the master cylinder, if the system is working properly when you turn the ignition to the on position you usually can hear the small electric motor running (slight buzzing sound) for around 10 to 15 seconds and then it will run again about every 3 or more depressions of the brake pedal, the sound will appear to be coming from behind the instrument cluster, I see no way that this type of booster/ABS system could be causing your issue.

Hopefully someone else may have had this issue and solved it and can help you solve your issue.

 

[riceandpho]

have you cleaned the throttle body with the battery disconnected for 30 mins, then let the truck idle for 15 mins when done.

 

[Docholliday5645]

I had an idle problem when I first got my 05 a couple months ago. Engine would die without throttle. I was worried about a costly problem but it turned out that the idle control needed a reset because the battery had just been replaced. Was just a 5 minute fix! Try that before spending time/money on troubleshooting.

 

[who done it]

You guys were right, throttle body cleaned and gasket replaced. Runs good now. Thank you all for your help.

Sent from my SM-G892U using Tapatalk