2001 General Tech questions from 2001

LinkBack Thread Tools Search this Thread Display Modes
post #1 of 6 (permalink) Old Sep 27th, 01, 5:56 AM Thread Starter
Senior Tech Team
Join Date: Sep 1998
Location: Mustang, OK USA
Posts: 11,488
Apparently 68 Chevelles did not have a heater control valve to shut off the water to the heater core. Just the opening and closing of the doors inside the heater and air cond plenum is what controled the temp (I guess). The heater core in my son's 68 started leaking so I disconnected the heater hoses and looped one to bypass the water. WOW! THE AIR CONDITIONER IS FREEZING COLD NOW!!! Has anyone rigged up a heater control valve on their 68 (like maybe on a 70), other than installing a manual shutoff valve in a hose?

Or, was the 68 SUPPOSED TO HAVE a valve, and maybe someone in the past removed it?

Tom Parsons

[This message has been edited by DZAUTO (edited 09-27-2001).]
DZAUTO is offline  
Sponsored Links
post #2 of 6 (permalink) Old Sep 27th, 01, 6:07 AM
Lifetime Premium Member
Join Date: Jul 1999
Location: Lubbock TX
Posts: 890
Yes, if it's factory A/C there should be a vacuum operated valve mounted on the front passenger side fenderwell.

Jim H
69 Malibu
doc j is offline  
post #3 of 6 (permalink) Old Sep 27th, 01, 7:35 AM
Gold Member
Join Date: Sep 1998
Location: Tucson, AZ, USA
Posts: 8,754
Year One does list a valve for '69 and up models, but nothing for the '68. If you have a shop manual or assembly manual you should be able to figure what type (if any) valve you need. It probably would be pretty easy to adapt a valve to your car.
JWagner is online now  
post #4 of 6 (permalink) Old Sep 27th, 01, 1:03 PM
Tech Team
Join Date: Sep 2000
Location: Madison, Alabama USA
Posts: 874
There should indeed be an inline water temperature control valve mounted to the passenger side inner fender for 68. I believe it is cable controled, rather than vaccuum. Part number 3400672.

Patrick, aka Merlin
1968 SS 396/325 4-Speed, White with black vinyl top & black interior.
Merlin is offline  
post #5 of 6 (permalink) Old Sep 27th, 01, 4:42 PM Thread Starter
Senior Tech Team
Join Date: Sep 1998
Location: Mustang, OK USA
Posts: 11,488
Then, if that is the case, my is gone, and there is no evidence of anything to actuate the valve (loose vac hose or cable). Is it possible that a 68 300 Delux didn't get a heater control valve with factory AC? Could some of you guys who have a 68 with factory AC go raise your hoods and see what your cars have in the way of a valve in one of the heater hoses?

Tom Parsons
DZAUTO is offline  
post #6 of 6 (permalink) Old Sep 27th, 01, 9:21 PM
Senior Tech Team
Join Date: Jan 2000
Location: Corpus Christi, Texas
Posts: 2,922
On '69 and up the valve closed with vacuum and opened with lack of vacuum. On '68 it was the other way around. Mine was missing, but this is the way it was shown in an old Heating and Air book at the local parts house. The '69 had provision for mounting the valve on the firewall, but the '68 didn't have this (again according to the book at the parts store).

I also had vacuum lines running into a block on the temperature control lever from the firewall, but mine were cut off at the firewall and no valve was present when I got the car. The HVAC control panel was broken, and no more good to me. I found a few more panels from other '68 Chevelles, but each one was different. I think this had a lot to do with the confusion from the UAW strike during those production runs.

I'm not sure about the "concours correct" way to install it, but this is what I found in my research. I installed a '69 valve on mine simply because it was in stock at the parts house and I'm not concerned about originality. It was also nice to have a bracket mounted to it. Now I just have to figure out a clean way to control it from the cockpit. For now I just disconnect the vacuum under the hood when I want it hot.

My Web Page (updated 9-17-01)

"I pledge allegiance to the Flag of The United States of America."

Chad Landry
TC Member #643
ACES Member #04556
'68 El Camino

[This message has been edited by cjlandry (edited 09-27-2001).]
cjlandry is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Chevelle Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address. Note, you will be sent a confirmation request to this address.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Old Thread Warning
This Thread is more than 5722 days old. It is very likely that it does not need any further discussion and thus bumping it serves no purpose.
If you still feel it is necessary to make a new reply, you can still do so though.

Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome