I was unable to take a picture tonight but I will describe it as best as possible. I was under the hood tonight filling the wiper fluid when I heard a vacuum leak. I followed the noise and found a vacuum line that was broken off of a black plastic ball located near the corner where the firewall and driver side fender meet. I have never seen this type of part before and was wondering if anyone could tell me what it is called and possibly what it does. Thanks

 

if it has only one line in it its probably the Vacuum Reservoir.

 

That sounds pretty likely. It does only have 1 line going into it. Not sure how long it has been broke but the previous owner has about 3 ft of extra wiring and stuff in that area from what I think was a security system so it may have been broken sense the installation or removal of some of those components

 

If the ball is aboit 5 or 6 inches in diameter it's definately the vacuum tank. It stores vacuum for when you don't have high vacuum in your engine. Everything from cruise control to heat/air conditioning actuators taps into this. If you have a broken one, you should replace it. Your engine will run better-promise.

 

I think it is definitely the vacuum reservoir after hearing what you guys have said and looking at pics online. However I have no problems with anything. HVAC, Cruise, 4x4, etc all work perfectly fine. I will still replace it tho if I can find one. I have not been able to find one listed at any of the auto parts places or even on oem part sites.

 

www.rockauto.com


DORMAN Part # 47077 $9.37 Round Vacuum Reservoir

1984 CHEVROLET BLAZER 5.7L 350cid V8 4BBL (L) : Emission : Vacuum Reservoir


I don't know what year your Blazer is, but this one would probably work. I have a 96 Blazer, but there is no listing for the reservoir under the 96 Blazer parts list.

Maybe someone else will chime in with another source.

Another possibility:

ACDELCO Part # 14078506 $32.79 Round Vacuum Reservoir

1990 CHEVROLET S10 BLAZER 4.3L 262cid V6 TBI (Z) : Emission : Vacuum Rese

There is also one available at www.gmpartsdirect.com for $ 25.06. Search 14078506 on the first screen. It does not show up for 96 blazer either.

 

I also have a 96 w/ 4.3 4x4 and is probably why i can not find a listing for one

 

Just to add my two cents (which is about what it's worth with inflation) I have one on my 94 S10 Blazer and on my 84 S15 GMC Jimmy.

 

I got mine out of a junk yard off a '97 Bravada that was rolled lol

 

I have on in a 95 blazer sitting in my garage that I can wrench it off of.