I have a 95 4runner with 167k and only 8k on rebuilt motor. All was going fine and one day when I hit the breaks the truck died and at the same time my headlights went off. Long story short, I took it in to Toyota and they said they replaced a piece of bad vacuum hose and that is fixed. Drove fine for 2 weeks and the same thing happend so i started looking under the hood and replaced 12 vacuum hoses(only 2 had pin holes in them) and the truck ran fine again but for only about 2 days this time. So I then replaced every piece of hose I could find and now it dies everysingle time i tap on the brakes.............anybody ever experience this or have a clue whats going on? I have no way to tow it to the shop and right now can't afford to have it towed by a tow truck so i would like to fix it if i could but I'm lost as to where to look for the problem. Since I replaced all the hoses i don't think that was ever the problem at all??????

 

my p/u does it when i have a vacuum leak

 

Try pinching off that main vacuum line to the brake booster under the hood.
Then try it with the vehicle in neutral,..don't drive it with the vacum line pinched off...it's not safe. This is just to test the vacuum booster integrity. If you still have the problem I would be looking under the dash for wires possibly shorting on the brake linkage.

 

Definitely sounds like a leaking vacuum booster. Try what scrid suggested and see if that helps. If it does replace that booster, soon before you get left with no power brakes.

 

Definately sounds like the break booster diaphragm has a break in it somewhere.

 

Okay i took off the vacuum hose to the boster and plugged it and yes the truck still dies when i hit the brakes while in park. i can't check it in nuetral yet because my stater went out while checking it..............so i am in the process of rebuilding it but does that sound like its still a leaking booster or someting else? Any other suggestions on what/how to test for my problem?

 

It's a vaccum leak.
Could be the booster.

 

So if its my booster is there a rebuild kit for it or do i have to buy a whole new master cylinder?

 

Personally I think it's easier to just swap the cylinder with a new one then to rebuild it.

 

Did you plug the line, or the booster?

 

It's not electrical.

It happens when he presses the brakes, brakes run off vaccum.

 

Yeah Tony, and we covered the booster earlier.
Which is why we suggested blocking the vacuum line to it for testing purposes.
Do you know of some other vacuum line associated with the brakes that would cause the engine to die?


shansethp
When you get your starter back on. Test and see if the headlights still go off like the first time.

P.S. I'm pretty sure you can't rebuild the booster, I think you only have the option to replace.

 

On a Toyota, no.

I know when I had a crank case line rerouted to a 'catch can instead of my intake that my Jeep ran like crap, stalled at stop signs and through engine codes.
Hooked back up to the intake and the problems went away.

Hopefully he'll get back to us with test results after replacing the starter.

 

There is a slim chance it could be electrical. Whenever you press the brake pedal your brake lights come on. You have said that your headlights failed first and now you have a starter problem too. All electrical. Maybe the brake light circuit is shorting out the ignition somehow....
Pull out the brake lights fuse and try again.

 

did you try pushing the clutch in too? my truck dies if i only press on the breaks

 

Good suggestion,... I was going to also suggest unplugging the brake light switch to test.

 

Well i did get the starter fixed and reinstalled. before i went any farther i replaced a few more vacuum hoses i found i had missed before but they were still good but then I noticed on the back of the manifold by the firewall a vacuum hose was missing. I traced it down in my book's diagram and found it was the line that goes to the charcoal cannister. Sure enough the cannister had a line just dangling, so i hooked it back up. i started the truck up and couldn't get it to die anymore when i hit the brakes. so i thought if that was the problem i should be able to again un hook that hose and have it happen right? Nope, wouldn't die or even shutter at all?????????? now i have no idea whats going on! However I did go ahead and take out the brake light switch and check it and it was good. Perhaps it was that vacuum hose after all from the cannister causing all this? Whats the chance it was something the starter was doing.......none of the wires were loose or anything but it really bugs me that my truck runs fine now but i really didn't come up with a sure fire fix or anything. To answer a question from earlier in the thread, when I tested the booster i clamped off the line running from booster to the intake plenum. i disconnected it at the brass one way valve on the firewall and stuck a bolt in the end of the hose, started the motor ,hit the brakes and it still died. Any further thoughts guys?

 

Listen - your truck sounds like it's fixed. This isn't a primarily womans/feminists discussion forum where we need to have a symposium on what happened after every incident to feel better about ourselves. Just accept it for what it is, and drive it with a smile on your face! And if it happens again, let us know! haha
OK fine

I'd be interested in some potential theories too.

 

Excuse me for worrying if my truck is reliable or not. i come to this forum because there are far better mechanics out there willing to offer there advice on this forum to help out people like me. Love your screen name though......very mature As for the other posters who offered good sound advice I highly appreciate it!!

 

I guess my thoughts on this stem from owning a Jeep but if the problem magically goes away, I'm not gonna worry about it anymore lol.

Glad to hear it's fixed.