1999 Jeep Grand Cherokee BRAKE / AIR LINE (??) question
Today when I started my Jeep, a fairly loud sound of air escaping came - it
sounded to me like an air hose has a hole or busted. . . . The sound continues
anytime the Jeep is running, but decreases or stops completely based on
how much pressure I put on the Brake Peddle. Brakes seem to be working
fine, after approx 10 mile drive . . . No leaking under the Jeep . . . I can’t “feel”
air shooting out around the brake peddle but that’s where it sounds like it is
coming from. As a newly divorced BROKE woman who just moved to a state
where I do not know anyone or what mechanic to trust, I am seeking ideas of
what it might be, or how urgent it may be. Is there an air hose that connects
to the brakes ? Will the brakes STOP if I can’t afford to fix it for a couple of
weeks?? It’s my only vehicle but can’t afford a big maintenance bill now.
Ideas? Suggestions of what it might be? Thanks - any help is appreciated!
It sounds like the power brake booster has a hole in the diaphragm allowing air to escape. It runs off a vacuum hose that hooks into the intake manifold. I'm not sure if you feel an air leak. This vacuum leak can be heard but it probably isn't blowing air toward the brake pedal. You might be able to drive it like that but it will take a lot more force on the brake pedal to get stopped. Next. You can open the hood and look around where brake fluid is added. That 12" round metal canister is the brake vacuum canister. There will be a 3/4" black hose that may have come loose from the silver aluminum intake manifold. If it is disconnected, that's your air leak....plug it back into the fitting. If that's what you find, then the brake booster diaphragm has NOT failed. Have someone help you look it over. If you're lucky, that's all that is wrong. Sorry about your hardship. Best wishes for your new year.
Hornet_2497: THANK YOU SOOOOO MUCH!!! Tomorrow I am going to tackle this. I did not feel air leak inside, but haven’t really got down and looked good yet. I will tomorrow, though. Please check back - I may need more advice, depending on what I find! Haha. Thank you for the well wishes - this year is going to be wonderful . . . Anyone who has ever gone through a divorce knows you take a step backward before going forward - I’m finished with the backward, and looking forward to the forward direction. I am determined I can fix the Jeep, so I’ll let you know what I find tomorrow. Thanks again!
Hornet_2497 . ... or anyone else who might know... . I have attached pictures and a video (actually sound). I can only hear the leak inside the cab - it does sound like it’s coming from somewhere under the dash around the brake peddle. I checked all these hoses (other 2 pictures) and fluid level . . . I could not find any hoses detached or loose. I pushed on all of them with no luck. . . .,noise still there. Is the round canister thing vertically positioned the brake vacuum canister you mentioned? Is the silver molded aluminum thing on the front of that the intake manifold? There doesn’t seem to be a hose from it, or anywhere one may have been. I did see the 3/4” hose higher up attached by a black round thing to the canister mentioned. Is the brake booster diaphragm INSIDE this black canister? If so, it doesn’t appear it would be too horrible to get to. It seems I can’t attach more than one photo below, so I’ll post more in continuing comments
Nice photos. Just like my Jeep that once had a failed brake booster. There is a rubber diaphragm inside the black, round canister that tears with age/wear, allowing the vacuum leak to occur, and the brake pedal will be stiff. You will have to get that brake booster replaced. Have a mechanic look at it to confirm. Should be about $200-$250 job including parts/labor.
