[Rick Jones]

Here is a pic of the three vacuum lines that come through the firewall. where do the red and black lines go to? I am guessing black is the vacuum source and red goes to the heater valve. Is that correct?

Thanks, Rick

[Transamric]

Basically,...yes. Your FB must not be a fairly late production since it has the water control valve. Later production, like '72, did not use the valve, so only had two vaccum hoses routed throught the firewall grommet.
The '71 Shop Manual shows the Black tube running to a vacuum check valve, then to engine vacuum. The light Gray, probably your White, goes to the purge diaphram, & the Maroon, your Red, goes to the inner fender mounted water contril valve.

[rock]

red goes to the heater valve
black goes on the back of carb (should have a one way check valve)
white is in the correct location.
hope that helps.

[Transamric]

There must be an echo in here!!

[Rick Jones]

Thanks guys. Tramsamric, you are correct. My car is a January 1971 build.

[prexford]

Rick,
Where does your red (maroon) vacuum line connect to once inside the firewall? I have a May 1971 built firebird and only have a gray and black line coming out. However I do have a water valve that needs a marron tube connected to it to make it work.

[70RAlll]

Originally Posted by prexford

Rick,
Where does your red (maroon) vacuum line connect to once inside the firewall? I have a May 1971 built firebird and only have a gray and black line coming out. However I do have a water valve that needs a marron tube connected to it to make it work.

The assembly manual; shows that the water control valve was not used on 1971 HO engines. I am pretty sure it was not used on regular firebirds in 1971, but the HO engine did not use it any longer for sure. The 71HO/71FB vacuum harnesses only had 2 vacuum lines exiting the firewayy-they do not still have the maroon vacuum hose.. The plug still has 3 holes, just is plugged on the non used hole. I don't know where others get the information that 71 TA ever used a water control valve like 1970's did, but I disagree with this.
Additional proof of this is the 5/8" heater hose that ran from the heater box to the rear of the passengers side head had a different part number(because it was one solid piece, not 2 pieces seperated by the water control valve as in 1970). The 1970 hose number is 482482 and the 1971 hose(5/8) # is 509043.. The valve you are talking about is #9774799. It was used on late 1960's Pontiacs also, but was not used starting the 1971 model year any longer. Your firewall should not have the maroon hard vacuum line comming out from any 1971 Firebird. This is clearly stated in the assembly manual.

Could you have an early(late 1970) car that still has the 3 vacuum line(including the maroon one) I guess.. But with the strike late 1970, I seriously doubt many, if any, cars were assembled with the incorrect 3 line vacuum hose set up(should be 2 like one member listed)..The grey goes to the large vacuum cannister on top of the heater box and the black goes to the vacuum tree at the rear of the Quadrajet and should have a black one way check valve inline between the carb and the hard vacuum hose using a small section of tiney soft rubber hose.

I am sure others will disagree with me.. But look on an original 1971 passengers side inner fender, you will see 2 dimples where the heater valves bracket would have gone. They will not be punched oput on a real 1971 inner fender.. Like I said...I am sure others will disagree with me.. Just like there are those who insist that all 1971 HO's used the idle stop solenoid, which they didn't.. automatic HO's didn;t for sure.. So this is my 2c's ....

[wwilder9]

Maybe 71 is the change over year. If you look at these pics I see the maroon line going to something on the wheel well, The picture is a 71TA HO four speed, I can take more pictures if I need to.

[prexford]

Thanks 70RAIII....you described everthing I have; only 2 lines (Grey and Black), a plug in the third hole on the firewall gromet and dimples on the fender well for the heater valve braket . Someone just installed a water control valve on my car thinking it was required...I'll take it off. Does the 5/8" hose have a pre-formed 90 degree on it to make the turn back to the heater box? I also noticed my black line going to the carb vacuum tree is missing the "check valve". Do you know where to get one of these? I'm wondering if this might be causing a slight vacuum leak that occasionally causes misfire/hesitation.

[70RAlll]

Originally Posted by prexford

Thanks 70RAIII....you described everthing I have; only 2 lines (Grey and Black), a plug in the third hole on the firewall gromet and dimples on the fender well for the heater valve braket . Someone just installed a water control valve on my car thinking it was required...I'll take it off. Does the 5/8" hose have a pre-formed 90 degree on it to make the turn back to the heater box? I also noticed my black line going to the carb vacuum tree is missing the "check valve". Do you know where to get one of these? I'm wondering if this might be causing a slight vacuum leak that occasionally causes misfire/hesitation.

prexford- yes, your car is exactly as they were spec'd out in the assembly manual.first, the vacuum check valve.. if you aren't concerned about originality...NAPA/AutoZone sell these in their "HELP!" sections.. they are usually black and white.. The originals are hard to find.. Expecially NOS ones. The 5/8" hose was not bent, but the manual called for a tie strap(same as used on the 3/4" hose to A/C line) to attach the 5/8" to the POA valves output metal line.This kept it out of the way..
As far as pictures showing what look to be original cars with the 1970 style set up... one of two things.. really early made 1971(like 8/70 or so) or a car that was rebuild years ago and has had miles put on it. I bought a car 4 years ago that I just new was "as found" original.. had all the grime etc in the right places.,.. just looked right.. started taking it apart(it was a formula I was using for parts) and dam'it if this stupid car had been rebodied at some point. The hidden vin numbers were wrong.. So just because a old grimey car looks like it has never been touched doesn't mean it hasn't. I learned this with that formula.. So many things could happen over 30 years.. So the picture shown is eaither an early car that still used old parts or has been rebuilt at some point years ago(I am positive I will get arguments with this comment, but it happened to me...)

[wwilder9]

I'll try to get some more pictures of my car to see if it has been altered or messed with, Like 70RAIII said "So many things could happen over 30 years..".

[70RAlll]

Originally Posted by wwilder9

I'll try to get some more pictures of my car to see if it has been altered or messed with, Like 70RAIII said "So many things could happen over 30 years..".

wwilder9-
by no means am I trying to make the point that your car is infact not original. There is no way I could do so without seeing it in person. I just know the experience I had with that parts car 4 years ago. I just knew it was all original, grime/rust in the right places etc.. the whole rear end was rusted out(otherwise being a formy I would have restored it !!) But it is a fact that the 71's were spec'd out not using the heater valve any longer as they did from 1970 back to something like 1967 or so..
Wwilder9...I learned a long time ago never to say never when it comes to our cars. Yours could have easily been made with 1970 harnesses and heater valve. But I guess the main point I was trying to make is that the Firbirds were spec'd without the heater valve in 1970,hence the 2 hard line vacuum lines vs the 3 hard line vacuum set up. I have seen original cars where people have added the heater valve,and idle stop solenoid on auto cars for that matter, thinking their car was incorrect and trying to make it correct. Anything could account for your 1971 car having a heater valve. I could see in hot climates people adding the heater valve to help with the a/c system...

Where was your car made and when?? I have seen Van Nuys cars that have continued using parts from previous years....Your car looks like an "as found" car with all teh rust and grime in teh right places-sans the black scoop.. Anyway, please do not take my comments as a swipe against your car.. It wasn't meant as such..

[165th]

Does anyone have a picture of the black vacuum check valve and what vacuum port on the carb does it terminate at?

[prexford]

I took out the water control valve and inserted the vacuum check valve...heater works great. Now I'm not getting any air from the dash vents. The door in the heater core (inside, under glove box) will not move when I switch from any of funtions on the a/c control panel. which vacum line contols this function?

[70RAlll]

Originally Posted by prexford

I took out the water control valve and inserted the vacuum check valve...heater works great. Now I'm not getting any air from the dash vents. The door in the heater core (inside, under glove box) will not move when I switch from any of funtions on the a/c control panel. which vacum line contols this function?

Have you tried turning your vacuum check valve around?? It is directional and will not work inserted the wrong direction...Inserted wrong direction, will loose all functions of HVAC control panel except one, probably the heater...

[70RAlll]

Originally Posted by 165th

Does anyone have a picture of the black vacuum check valve and what vacuum port on the carb does it terminate at?

It terminates on the passengers side vacuum port(small one) from the vacuum "tree" that comes off the rear of your Quadrajet. The "tree" is the pot metal/aluminum piece that is threaded 1/8thx27 and screws into the rear baseplate of the Quadrajet. You get your vacuum for the power brake booster from this "tree".. there is probably a more correct term for this part, I have just always called them vacuum tree's, as they look like a tree with branches comming off the sides.. If no one else can supply a picture, I can get you one later this evening.. There is a part number on the side of them.. Pretty hard to come across NOS, used ones come up every once in a while on Ebay.. Last one I saw sold for almost $100!! Unless you just have to have a 100% correct car, I would get one from NAPA or Autozone.. They sell the white/black ones and you could just paint the entire piece black...Just a thought...
Anyway, I will get you a picture of one later this evening...

[70RAlll]

Originally Posted by 70RAlll

Have you tried turning your vacuum check valve around?? It is directional and will not work inserted the wrong direction...Inserted wrong direction, will loose all functions of HVAC control panel except one, probably the heater...

ALso, the vacuum from this check valve goes to your HVAC switches and controls all HVAC functions. It is a vacuum operated system. I still think you have the check valve inserted incorrectly. Try hooking vacuum line up without the check valve and see if everything works. Make sure you are getting vacuum to the point you are hooking it up to. It needs to be full vacuum at all times, not a ported vacuum source.If it does work doing this test, then your check valve is either inserted in the wrong direction, or the valve is not working.. It will not harm the system to run without the check valve for this test...

[prexford]

I ran a straight line without the check valve and still did not work. I was thinking, I might have pulled a vacuum line when I was under the dash however, I double checked and every vacuum line is accounted for. It was blowing right before I took off the water valve and replaced the heater hose going to the case. Is it something electrical that conrtrols the movement of the heater case door ?

[BobC]

Here's a pic of the passenger inner fender from a Jan. '71 Van Nuys 455 HO Formula. There's a valve and bracket that appears to be original. I don't know the history of the car from new though.

[70RAlll]

Originally Posted by BobC

Here's a pic of the passenger inner fender from a Jan. '71 Van Nuys 455 HO Formula. There's a valve and bracket that appears to be original. I don't know the history of the car from new though.

Bob- I swear...I think VanNuys was 6 months behind on the model year changeovers. Aside from that car having the heater valve, it also has the "mud flaps" on the inner fenders which I am pretty sure was another non 1971 spec'd item that was used on 1970 models. I have seen this before again and again on Van Nuys cars...
Then again, as I said-and no disrespect to anyones cars, you never know what has happened to a car over 40 years. A car could have been completely rebuild in the 1980's, driven another 50k miles and to us, would easily look original"as found" condition... I learned my lesson with that formy 4 years ago.. Truth be told, I was embarrassed to tell anyone that story until this thread. I paid more than I should have for that car just knowing it was an original, as found, complete formula 400. The body,especially the rear/trunk, was rusted to sh!t, but everything else looked ok.. I just knew I was going to get a bunch of good parts from it.. Ended up having all kind of miss matched parts.yes, I learned my lesson on that one.. Just because it looks original doesn't mean it is..
A previous owner could have added that heater valve easily if they were using the car in a extreme hot enviroment (Southwestern US,Lower Texas, Florida etc..) to keep the hot water out while using the A/C.. Still don't know why Pontiac quit using the valve...Just a $5 valve and a couple clamps and an extra foot of 5/8 hose -$10 production cost at most...