65 Riviera Vacuum Line Help

[Rockable]

I just purchased a 65 Riviera that is in really good, rust free, original condition. It is not a GS, the previous owner put the badges on it.

 

The previous owner was not mechanical and even though he kept it in a climate controlled garage, he neglected it. I have just finished demousing it, resurrecting the brake system, fixing some engine issues, working on the suspension and some other small issues. The one that is confronting me now is what I call "vacuum line hell". I think some of the vacuum lines have been connected wrong and I am having a hard time straightening it out. For now, I have the AC working but the heater controls are screwed up, for sure.

 

The attached picture shows a nylon tube off of the vacuum canister that I don't know where to attach. (Any help with that one is appreciated.) One leg is attached to a black tube that goes through the firewall grommet, so I assume that is correct. I've looked at the service manual but my problem is that most of the colors are not visible on the vacuum lines. Is there a set orientation of these lines in the firewall grommet? If not, what is the easiest way to ascertain the correct color codes for the tubes?

 

Another question that is unrelated to vacuum is, "How do you adjust the hood latch up and down. I need to lower it a little but don't see any adjustment. I have ordered the body manual but it hasn't come yet. Thanks!

[1965rivgs]

  Someone has added the nylon line so where it went was up to the person who modified it. The black line from the "T" is your vacuum feed to the control head in the console and should go into the firewall grommet.

  Depending on the degree of hacking and whacking which has occurred you shouldn't need the color stripes.

  The shortest line should feed your STV vacuum diaphragm.

  The longest line should feed the heater control valve.

  The four remaining lines should be two pairs.

  The shortest pair feed the heat/AC vacuum actuator which is clearly visible inboard of the blower motor on the firewall ductwork.

  The longer pair feed the recirc actuator which is out of sight on the underside of the blower motor housing.

  If the lines are mutilated get together some golf tees and preferably two vacuum gauges and the shop manual and use the process of elimination by manipulating the controls and finding where vacuum shows up.

  In the shop manual you will find an illustration which explains which vacuum hoses are actuated in each position of the switches and slide levers.

  Have fun,

 

Tom Mooney

Edited July 7, 2023 by 1965rivgs (see edit history)

[Rockable]

I got the heat/AC actuator and the recirc actuator plumbed correctly, I believe. There was a long tube and I connected it to the heater control valve but I don't get any vacuum when I move the heat control lever. I also believe I have the STV vacuum diaphragm plumbed correctly. The AC works great, as long as I have the heater control valve off. The spare line was originally plumbed to the heater control valve but that kept it open all the time. The car came with the vacuum operated trunk release but it was disabled. Perhaps that is what the extra line was for?

 

Thanks for your help! Have a Happy Fourth!

[1965rivgs]

On 7/4/2023 at 3:30 PM, Rockable said:

I got the heat/AC actuator and the recirc actuator plumbed correctly, I believe. There was a long tube and I connected it to the heater control valve but I don't get any vacuum when I move the heat control lever. I also believe I have the STV vacuum diaphragm plumbed correctly. The AC works great, as long as I have the heater control valve off. The spare line was originally plumbed to the heater control valve but that kept it open all the time. The car came with the vacuum operated trunk release but it was disabled. Perhaps that is what the extra line was for?

 

Thanks for your help! Have a Happy Fourth!

    If the operator calls for any heater function and AC simultaneously the heat/AC actuator will lose vacuum to one of the two hoses and moves to a partially activated position. This moves the heat/AC door so that it splits blower volume between the heater core and the evaporator core. You shouldn't lose AC but a greatly reduced blower volume at the AC registers and the presence of blower volume at either the heat registers or the defrost register depending on where the slide levers are positioned. This is normal operation.

  It is a common problem to find corrosion in the disc shaped vacuum diverters due to the presence of antifreeze. If the diaphragm in the heater control valve has ever failed it will allow coolant to be drawn into the system and set up the corrosion.     Pull the rubber gang plug off the disc and make sure corrosion is not blocking the nipples of the disc. It may help to introduce some penetrant into the disc and work the levers.

  Personally, I would blow out the penetrant with compressed air as in the long term it may do as much harm as good if allowed to languish in the disc...or, use a silicone based lubricant and skip the compressed air flushing.

  Good luck!

Tom Mooney