96xj 4.0 just little over 200k

just trying to pick some brains on wtf is with my jeep.. had an idoit jump in front of me and I had to lock down on the brakes but when I did the engine started to stumble and smoke and had a good bit of a knock to it.. pulled off the road and switched it off.. switched it back on and used obd2 adapter to check for pending/logged codes and got a code for injector #4 sticking so I poped open the hood and looked at the connector just to make sure and it was fine but i also noticed that the brake fluid was dam near empty and I just filled it a week prior.. started it up after topping off the fluid and it ran fine no knock or smoke .. now I've got some 4port injectors from k suspension and im going to change the rear wheel cylinders to make sure there's no leaks there but has anyone ever seen this before?? Someone said it could be the brake booster and best way to check is to pump the brake firm hold it and start the jeep with it held and if it kicks back or doesn't want to move the booster needs replaced.. well my brake fell nice and smoothly to the floor but it has a bit of a woosh sound and after I continued to hold it down that stumble came back.. it wont do it just average braking at lights and such just when i push the pedal all the way down with force.. someone also mentioned a check valve could be causing the stumble and the loss of fluid..

I have a big road trip in a month and trying to figure this out before then and you folks have had more jeep experience that my local backyard mechanics that work on gms daily lol


I AM NOT A MECHANIC BY ANY MEANS BUT ANY HELP TO POINT ME IN THE RIGHT DIRECTION WOULD BE GREATLY APPRECIATED

 

It lost a good amount of brake fluid suddenly, with no visual signs of an external leak?

I am just throwing a thought or two at you. I must preface this post to let you know, I do not really know what I am talking about? I have no experience when it comes to a brake booster and master cylinder, or with having an internal leak to the booster, and the effects, etc... That, and brakes are a super important thing to make sure to get them right!

Have you looked very closely all around and behind the master cylinder, and where it connects to the brake booster directly behind it at the firewall? Did you say there was some smoke when this happened? If any brake fluid leaked out from the braking system externally, it could cause smoke when leaking onto hot parts, and this would make some more sense.

I know when a brake booster has an issue, sometimes it can actually cause poor engine like type of running conditions to occur somehow, but I cannot seem to remember exactly why or how it goes about doing that.. anybody know?

I believe you can look and inspect the brake booster for an internal leak pretty easily. I do not know the layout and operation exactly for this stuff, etc...

There is a vacuum line going to the booster right behind the master cylinder. Run the Jeep and shut it off after five to ten minutes. Remove this vacuum line going into the brake booster. You should hear a 'hissing' type sound from the vacuum released, and this is a normal thing to hear. However, if you also hear a 'sloshing around' type of sound too, this is close evidence for having an internal brake fluid leak into the brake booster. You should not hear the sloshing sound when you disconnect the vacuum line from the booster.

You can use something like one or two zip ties linked together to feed down into the booster here at the vacuum connection site of the brake booster. If when you pull whatever you use back out of the booster you see brake fluid is on it, then that is evidence of having an internal brake fluid leak into the brake booster...

Attached below is a still shot picture of what was seen when a scope had been fed down into someone else's brake booster. It shows evidence of this guy having had his trucks brake fluid leak internally inside of his booster. The guy said there was more than 20ml of brake fluid which had leaked into his brake booster when he sucked it out of there. He ended up replacing the brake booster. I do not know what were the symptoms he was having, aside from having low fluid level in his trucks master cylinder?

It is a little hard to see the fluid. Do you see?

 

The smoke was from the exhaust like I poured seafoam in it.. checked around both sides of the firewall where it mounts and didn't see any leaks but I know once in awhile ill get in and it looks like some moisture is coming from the connection to the pedal on the inside but I live in very humid conditions and I only see it once in a awhile so im assuming its moisture.. i was told my right rear wheel cylinder was bad when I got tires recently so I ordered them and have yet to out them in nor have I personally seen the cylinder leaking so the loss of fluid may be that but for the whole thing to be empty that quickly I thought it may be something else.. im going to go pull that vacuum line off here in a bit and try the zip ties and see if I find any fluid and let you know what I find.. thanks

 

Copied and pasted:

With brake fluid inside the power brake booster, the intake manifold is able to inhale the brake fluid into the engine whenever the brake pedal is depressed. This would be the cause of the white smoke.

 

Well she's got fluid in the large drum.. took the vacuum line and check valve off dropped a thin piece of speaker wire down in there and pulled it out covered in fluid.. so im guessing I just need to replace that large black drum and not the silverish deal thats holding the fluid and the brake lines are attached to it? I'm also gonna assume there's gaskets to the silver deal and to the firewall for the drum also

 

I think you are probably going to want to get an expert opinion on this one? I would..

There are probably tricks of the trade to deal with when having an issue such as this one, and maybe a few other parts and pieces to replace if needed while going about getting the primary issue repaired.