Cabin heat
Thread Starter
Racer
Joined: Nov 2009
Posts: 489
Likes: 1
From: Suffolk Virginia
Cabin heat
I have 2 questions:
1: Exactly what is this?
It's on my 5/8 heater hose. I want to install a shut off valve to cut down on cabin heat, does it matter which side of this device I install?
2. I just had all my ductwork replaced, but still have very little air coming into the cabin. The mechanic told me the PO probably left the seal off the heater box. Does this sound right? I really don't want to go in there for nothing.
Thanks in advance,
-Jay
1: Exactly what is this?
It's on my 5/8 heater hose. I want to install a shut off valve to cut down on cabin heat, does it matter which side of this device I install?
2. I just had all my ductwork replaced, but still have very little air coming into the cabin. The mechanic told me the PO probably left the seal off the heater box. Does this sound right? I really don't want to go in there for nothing.
Thanks in advance,
-Jay
Le Mans Master
Joined: Aug 2006
Posts: 7,413
Likes: 1,552
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
That part in the picture is the water shut off valve. On my 74 when I turn the thumb wheel to hot, vacuum is supplied and the valve opens up to supply heat. First replacement lasted 5 years, second replacement lasted 5 minutes. Ended up at Home Depot and got a manual shut off.
Can't help with #2.
Can't help with #2.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Very little air may be due to a stopped up ac box, 30+ yr old cars tend to have all kinds os dead leaves, dust, dirt, mice, lizards etc stuck in there. Might also be due to a weak/anemic fan motor.
Burning Brakes
Joined: Apr 2009
Posts: 807
Likes: 2
From: VIRGINIA BEACH VIRGINIA
put a manual shut off valve between the factory shut off valve shown in the picture and the engine. I have one on mine and it works fine. No heat in the summer and plenty of heat in the winter.
Burning Brakes
Joined: Jan 2009
Posts: 1,224
Likes: 1
From: Clarksville Indiana
I have every piece of heater and a/c boxs/ducts all out on my work bench apart and there was all kinds of crap in everything. Enough feathers to stuff a pillow! When I was taking everything apart I noticed plenty of gaps and missing/loose caulk sealer that would cause issues year round. Putting back in a c-4 blower motor and with it all cleaned out and sealed up hoping it works good.
Last edited by 71coupe454; Apr 18, 2010 at 11:59 AM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
Melting Slicks
Joined: Mar 2005
Posts: 2,093
Likes: 297
From: Midlothian VA
Either in front of the blower squirrel cage OR
more likely between the cage and the A/C evaporator coil.
Mine had a bird nest sucked into it - required complete removal of the A/C evap box.
You can test this by removing the interior duct work and checking your air flow directly out of the heater core. If it's still low then you have a blockage on the other side.
Melting Slicks
Joined: Mar 2005
Posts: 2,093
Likes: 297
From: Midlothian VA
Evap box is on other side of the firewall in the engine compartment.
You'll need access to both as they share a common bolt.
Removing the evap box is not as difficult as it looks but is
considerably more difficult than the heater box.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Heater & Air distribution box is under the dash attached to the firewall.
Evap box is on other side of the firewall in the engine compartment.
You'll need access to both as they share a common bolt.
Removing the evap box is not as difficult as it looks but is
considerably more difficult than the heater box.
Evap box is on other side of the firewall in the engine compartment.
You'll need access to both as they share a common bolt.
Removing the evap box is not as difficult as it looks but is
considerably more difficult than the heater box.
While you have it off...
Look into a product called "Home Made Lizard Skin" Its an aircraft insulating paint, stops a Lot of heat transfer. Paint it on the inside and outside of the box as well as as much of the firewall as you can get to.
Melting Slicks
Joined: Oct 2002
Posts: 2,317
Likes: 111
From: St Louis MO
My solution was to add another (manual) shutoff valve in the other line to close for the summer and re-open when colder temperatures return.
Where you install a blocker valve in the heater lines does not matter because a block in that circuit will stop flow wherever it's located.
Pro
Joined: Jun 2008
Posts: 673
Likes: 2
From: Melbourne Victoria
Check out this thread on cabin heat:
http://forums.corvetteforum.com/c3-g...kpit-heat.html
Hope it helps.
GAV
http://forums.corvetteforum.com/c3-g...kpit-heat.html
Hope it helps.
GAV
Drifting
Joined: Jul 2009
Posts: 1,532
Likes: 14
From: Dallas-Fort Worth TX
This has got my interest. So the heater shut off valve is a stock set up, not a bubba set up?
Second when you come to a stop the vacuum stops and the valve opens letting heat/water thru in case you want to turn on the heater. But some are removing this and just putting in a manual off/on plumbing valve from Home Depot??
Second when you come to a stop the vacuum stops and the valve opens letting heat/water thru in case you want to turn on the heater. But some are removing this and just putting in a manual off/on plumbing valve from Home Depot??
Le Mans Master
Joined: Apr 2008
Posts: 9,419
Likes: 239
From: Powassan ON
$8 bucks and 20 minutes. Took me longer than 20min to build the tap setup.
dodosmike
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Have you reached down through the cowl and felt around the fan cage to see if its plugged up ?
In the pic below is an alternative to the shutoff valves , easy on , easy off , great for show cars.
In the pic below is an alternative to the shutoff valves , easy on , easy off , great for show cars.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
The large set are being used in the above pic,the owner is using the med. size on his 57 Nomad.
http://www.harborfreight.com/3-piece...set-97578.html
