Stalling when breaking :/

[joeshark]

Help. Don't know what the issue with this trick is; but I'm stalling when braking, sometimes even when it's not really even a hard brake.
The alternator gauge is just under the middle mark by a line or two. Oil pressure drops to one line above the quarter mark when stopped & in drive. It rises to around middle mark, while driving.
Thanks

 

[SunlitComet]

a brake booster that is failing or a vacuum leak can do this. if it happens specifically when you actually use the brakes to stop them you can retest by plugging the vacuum line on the booster BUT BEWARE YOU WILL LOOSE BRAKING POWER AND IT WILL TAKE LONGER TO STOP. you can also try the brakes while parked and see how the engine responds.

 

[joeshark]

Is it common for the brake booster to go bad slowly?
I just took car to autozone to have alternator/battery tested. Battery was in bed of replacement, alternator good. Bought new battery.
What are the operating ranges of the alternator, oil pressure? I've not had a vehicle with these gauges in years

Sent from my SM-N920T using Tapatalk

 

[SunlitComet]

mine had a small minor leak fora about 4 days and then just went to crap real fast after that. electrical power goes from about 12.7 when under a heavy load. at that point battery power is being used to about 13.7 when charging real well on a warm to hot day. the colder it is under the hood the likely hood the charging voltage will be lower so as not to overtake the battery when it is cold. not uncommon to see typical charging in the lower half of 13v. oil pressure on a well used engine can be typically 18-22psi when hot and idle or as much as 40-50 psi when cold starting. based on 5w-30 oil.

 

[joeshark]

Ok, so I'm thinking everything is good, the new battery has taken care of the line starting time. It was taking a long time cranking to get started, now right quick voltage, oil pressure, are good.
I'm still thinking the brake booster is probably still good.
It's it possible that if battery was on way out, that could've been causing stalling while heavy braking, because of drop in idle?

Sent from my SM-N920T using Tapatalk

 

[SunlitComet]

if the idle dropped down enough to where the alternator could not produce enough voltage and the battery was really dead then yes. it happens. did to me 2 weeks ago after suv sat for 2 month with out starting as i was in the hospital. if all seems fine keep monitoring for a while for any other problems.

 

[joeshark]

Thanks sunlit, so far seems like the battery was the issue done braking that otherwise would've stalled it out, so far so good, knock on wood.
Good thing I decided to check battery on a whim
Getting there little by little.

 

[joeshark]

Ugh, Ok so the problem is not gone So the most obvious culprit is brake booster? Or vacuum leak some where else; but how would it be possible to detect a vacuum leak somewhere else?

Sent from my SM-N920T using Tapatalk

 

[SunlitComet]

spray starting fluid lightly around the intake area and you can also try around the brake booster for starers but when mine leaked it leaked from inside the cab. that is not a place you want to spray starter fluid tho. If it is leaking from the cab you can likely hear hissing and feel the engine act up as you depress the brake pedal.

 

[joeshark]

Ok, so Yea I think this is beyond my capabilities :/
It's it possible that even if check engine light is not on, that if mechanic attached computer reader, they might get a code to highlight issue?


Sent from my SM-N920T using Tapatalk