Brake booster gone bad??? Pic..

This morning, when I started the jeep something sound strange. I made a big hissing sound before it started, I didn't think anything of it.

The brake pedal got very hard and stopping is difficult. I noticed the connector/fitting on the booster where the vacuum hose connects to was missing the cover.

What is this part called? Could I get it from the auto parts store?



Thanks..

it's a check valve for the booster-- allows engine vacuum to enter booster and assist in braking but shouldn't allow vacuum to exit the booster. In this case it's just an unregulated vacuum leak. See if it's available separately from local parts store, but you may end up buying the booster to get it.

I'll try to remove it and use it as reference...

Hope I don't need a complete booster..

the check valve should be easy to find, just pull on it, it pops right out of that grommet. take it to the parts store with you. dunno if there is a NAPA near you but our part number is

#89000 Vacuum brake booster check valve

hope this helps.
-G

X2 on the NAPA store having it.

Thanks guys for the feedback.

I was able to located it at a local auto parts store.

My first visit was to Advance Auto, I explained to the kid behind the counter where the part goes on the booster... He asks for help and looks in the computed and says "We don't have the part in stock, I would have to order it... this fitting is the Power Brake Booster, right" I said "Yes it is" I took a lot of control to not laugh. :roflmao: :roflmao: :roflmao:
I feel sorry for the people that go in there for help...

Thanks again..

Why do you think I quit working at schuck's?

I got tired of working with idiots....

So... I've been reading threads and blogs all day being more and more convinced I have to replace the entire booster in the 99 Cherokee Limited I just bought 3 weeks ago; and I (happily, I hope) find this thread.. so now the question.. do I need that $10 check valve/elbow that the vacuum line connects to which runs to the manifold, or an entire new booster? ISSUE: same as 01sesedan - LOUD hissing sound under the dash I traced to the rubber boot around the brake pedal linkage rod - NO brake assist. I figured a vacuum (leak?) that large meant I need an entire new booster. QUESTION: is it possible a vacuum leak so large it sounds like a semi trucks air brakes that I'm hearing INSIDE the vehicle and resulting in no braking assist really be caused by just that check valve being bad?? Thanks, Jeepsters!

the answer 99 is yes it could.

The hose that runs from the intake to the brake booster carries the vacume that assists with the braking function. when a hose that size gets a vac leak, it can be quite loud and have NO power to the power brakes, making you do all the work for braking pressure (same as when trying to brake with the engine off such as emergency towing).

I use a product called "Seafoam"- helps clean the inside of the engine- and I pour it into that hose that runs from the booster to the intake. When I take that hose off, I notice that there is a LOUD hissing sound, and the RPMs jump up on my 95. I do the same on my 99 Dodge Ram and the sound is the same but the RPMs dont jump.

That part should be able to help with the sound and braking issue. If you remove the hose from the boster and plug the end does the sound stop?

hope that helps
stewie

Hey Stewie! damn, this forum is great! never expected such a quick response! But... the problem is NOT the vacuum hose - which is brand new, but checked it anyway - pulled the hose off the booster, put my thumb over the end of the hose, no more sounds, and now have a nice hickey on my thumb LOL.. the question about it being a bad check valve/elbow (the black thing on the front of the booster that looks like an elbow the hose connects to and seats into the metal can of the booster) came up in another thread I was reading; so I'm kinda hoping that tiny little easily accessible, inexpensive, simple part could be bad and causing all the symptoms most of the other blogs diagnose as a bad booster. I'd much rather find out I can fix this with a $10 check valve instead of a $130 booster and all the hassle of bleeding lines, etc LOL

well 99, by removing the hose and plugging the end you just did a little bit of troubleshooting. you found that when plugged, the noise level returned to normal. this tells you that there is a problem in the line that you plugged which you have narrowed down to being the vac check valve. true, you havent checked the valve itself, but you know that the problem is narrowed down to that area.

you have two options to correct the problem- the first is the cheapest and easiest. you could replace the possibly faulty valve for about $10 and only minutes of your time or replace the whole booster for about a buck thirty and considerably longer. i like to try the quickest and easiest first. if that doesnt work, your only out a little bit. I would try the valve first (if you can figure out a way to test the old valve for leaks great but i havent had to deal with that part quite yet in my xj) to save time money and hassel. examine any rubber groments for the part before you go to the parts store. if the rubber is stiff, cracked or crumbling get new. heck, even if the old groment looks good its cheap insurance to replace it anyway because underhood temps take a toll on ruber and plastic components.

while your at it, you may want to examine the remainder of your vac system for problems. i found one craced vac line initially on my 95. since there was a problem in one area, i decided to check the remaining parts to be safe. after only about 3 minutes of checking i found out all the lines in my crankcase ventilation system needed replaceing. by being proactive i possibly saved myself some headache later on. I haddent thought about checking the valve you are having issues with, so i will have to check it in the morning when light is better. thanks for the reminder that i need to check mine.

if you have any questions about the repair or checking the rest of the vac system feel free to pm me.