just picked up a 69 Riv but the headlights are always down.. I use to have a 70 Cougar and at least when the car was running, the headlight doors would lower and after the car was turned off they would slowly rise up after a few min. Not sure how the Riv vacuum system works exactly Any suggestions on how where to start checking would be great, thanks !
First thing: Buy a model year 1969 Buick chassis manual :Smarty: Faxon offers Chassis Manuals on CD: Click banner for the 1969 Buick chassis manual :Comp: On my 1968 Riviera (also vacuum powered, 1966 & 1967 are electric) the headlight switch was the problem. It's a regular GM switch with a few extra parts and hoses to operate the vacuum headlights. Also the vacuum actuator is famous for causing trouble, new ones are available from GM Obsolete in Phoenix, AZ. But he's asking over US$ 250 for them. 1st generation Camaro RS actuators are almost the same, and you can make them fit your Riviera very easily. Further reading :Comp: Tips from Norway :Comp: Convert to electric power :Comp:
Your Chassis manual will have all the info you need about the vac system for the lights. I'm blessed that mine work well. Only issue I have is the R side light will fall open after the car sits for an hour or 2.
First get a view on the vacuum diagram. It could be anything, so it could be an easy vacuum leak. Start with checking the vacuum lines. I had one vacuum actuator worn (the rubber ring inside the actuator), they are easy to fix. Hardest part is to open it without damaging it. But no need to buy these new, they are very easy to fix.
The '68-'69 Shop Manual will have all the info you need to trouble shoot the vacumm headlight system on your Riviera. Also do a 'search' here, as the topic has been covered numnerous times. The '68-'69 Riviera vacumm system can be a royal P.I.T.A. to diagnose, as a single vacumm leak from a split hose end, or a faulty component, will render the system inoperative. :af: Clean an lubricate the headlight pod pivot points in the grill to ensure they move freely, and are not siezed. Check all the hose connections for cracked or split ends. Try listening for a tell-tale hisssssssss with the engine running, and the headlight switch in the 'off', or 'on' position to pin point a possible source for a vacumm leak. Closely examine the plastic vacumm distribution block on the lower portion of the firewall, as they did not age all that well, and are prone to stress cracks along the seams. The vacumm control relay inside the left front fender (...by the battery), could also be a possible problem, as the rubber diaphragm and control valve are prone to sticking with age or an accumulation of dirt. Apply a vacumm source to all the components, one at a time (Headlight Switch, Control Relay, Headlight Cannisters, and Vacumm Tank Check Valve) to ensure each is working as it should, and replace any faulty components. . . . are we having fun yet ??? :beer :TU:
Funny this thread comes up today. I went through my whole system today so its fresh in my head. I replaced all the hose right up to the headlight switch. I bought a 69 Camaro Rally Sport hose kit. The hoses have the correct red and green stripes and you'll have enough left over for spare pieces in the future The best thing you cando is remove that plastic vacuum block off the firewall and just use a vacuum T instead. The actuators can be tested with a vacuum pump. I had one bad actuator on mine so Im on the hunt for a working set. I stole one off the resto Riv temporarily The system is really not that hard to figure out. The PITA is trying to get good actuators.
Totally agree Jason - GM has a newer, sturdier, 4 port version of the vacumm distribution manifold to replace the old one. It's Grp. 9.755, Manifold, #1239606, if you can find one !! :TU:
Thanks for the tip Randy! I'll have to look into that. I like the idea of using the Camaro actuators, but I dont care for the way they were adapted for use with Rivieras. There's got to be a way to make the install a little "neater" looking (no offense to the poster that adapted them). Does that large rpound eyelet come off on the RS actuators? Can you maybe cut the eyelet off and thread the rod? If so, you could extend it with a piece of threaded rod and a coupling nut. Would look almost factory that way. GM Obsolete ones have come down a little in price. Looks like they're 225 each now. Still alot but a little easier to swallow.
Jason, this is exactly what I did to mine, I welded threaded rod onto them after cutting off the eyelets, it looks good, I can send pics of them on the car if you want
If you could that would be awesome Kurt:beers2: . If you cut the eyelet off, do you think that threads could be cut on the rod? Im like this close to ordering the GM Obsolete ones. I called them today and he told me that he has them manufactured for him. He also said that they are much higher quality. Im not sure of it was true or if he was giving me some hard sell Im loving my color coded new vacumm hoses. The Camaro hose kit is color coded identically to the Riv and fits like a glove
Getting back to the OP's original question... the way it works is this. You have a vacuum hose from the engine going into a storage tank that under the fender by the hood hinge. As the hose goes into the tank, there is a check valve to lock the vacuum in the system. There is another line leaving the tank that goes to a vacuum relay by the battery. This supplies the vacuum to the headlight actuators. We'll get to the vacuum relay in a minute Lets get back to the storage tank. There is another smaller line that leaves the storage tank and goes to the headlight switch. From there, a line leaves the switch and heads to the vacuum relay. This relay is basically a diverter valve. The vacuum relay has a diaphram and a plunger and it controls where the vacuum is directed to. The small line from the headlight switch is attached to the diaphram. There are three large lines conected to it- the supply line that came from the storage tank and the up and down lines to the headlights. So when the lights are off, vacuum flows through the headlight switch and compresses a spring and plunger inside the vacuum relay. This allows vacuum from the supply line to flow into the hose that controls the "up" position. When the lights are turned on, vacuum gets cut off from the headlight switch to the vacuum relay and the spring inside is released. This moves the plunger to its rest position and the supply goes to the hose that controls the "down" position. If one set of hoses to the headlights is supplied with vacuum, the other set is vented to air. So if the green hoses have vacuum, the red hoses are vented to ambient air -Green striped hoses are attached to the top of the actuator and control the down position -Red striped hoses are attached to the bottom of the actuators and control the up position. The up and down hoses split at the center of the grill and go to each actuator Clear as mud?? p Once you know how it works, its pretty easy to diagnose the system. Let us know how you make out with it.
cool, cool and cool again... good info guys, thanks. Going to mess with mine tomorrow and see what I can get done.
Here's some scans from the '68 Shop Manual to assist you. Erik has very kindly enlarged these, if you check the next post. :beer :TU: Let us know how you make out !!
Randy sent me the original scans, here they are :TU: Click the first scan for a bigger version :Comp:
