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I’m considering going to an electric vacuum pump for either the headlights or power brake. I seem to only get enough vacuum in my 383 for either or but not both. Anybody recommend some pumps I could look at or your experience with this install?
Last edited by Bluesting70; Jul 20, 2021 at 09:51 AM.
Just use a larger vacuum cannister or swap things over to electric. What size cam are you running? What is your vacuum reading at idle?
I’d like to do the electric headlight swap but not sure I’m ready to spend the $. If I remember right, I’m getting about 12-15 on idle. Cam below. Currently using manifold vac for dizzy and power brakes. When I plug in the headlights they don’t function unless I disconnect dizzy for headlights.
Last edited by Bluesting70; Jul 20, 2021 at 10:03 AM.
Electric vac pump out if late model wrangler or gm truck. They both will pull about 20-25" of vac continuously and are quiet. I have had to replace a few of the Wrangler ones but never one from gm.
12-15 in. Hg is PLENTY to run all of the vacuum systems in your C3. You must have a good vacuum reservoir tank with good one-way check valve in the feed line and VERY LITTLE LEAKAGE in the working lines and components. This is NOT hard to achieve. And you can do so for much less money than converting stuff to electric.And if you have power brakes, there must be a good check valve at the inlet to the booster, as well.
Take a couple of hours to query the Willcox web site for info on the vacuum systems for your year car. Study them so that you have a decent understanding of what the components do. There are only a few actions that can be taken by ANY vacuum system: Block or pass vacuum to another path (vacuum relays and switches); mechanically move something IN or OUT (vacuum servo 'motor' or actuator); transfer vacuum from one place to another (vacuum hoses, lines); store vacuum and maintain a steady level of it (reservoir tank).
We are talking "SIMPLE" stuff, here. Why do folks get all upset and bent out of shape over some leakage from a simple a$$ system???? Learn about it. Look up info on how to troubleshoot and diagnose vacuum system problems, then go find the issues with your system and repair them. Much easier process than re-engineering the existing systems.
I’d like to do the electric headlight swap but not sure I’m ready to spend the $. If I remember right, I’m getting about 12-15 on idle. Cam below. Currently using manifold vac for dizzy and power brakes. When I plug in the headlights they don’t function unless I disconnect dizzy for headlights.
The others beat me to it. You have vacuum leaks, that is plenty to run what you have. Make sure your vacuum tank is holding pressure too.
The others beat me to it. You have vacuum leaks, that is plenty to run what you have. Make sure your vacuum tank is holding pressure too.
I appreciate the feedback from everyone. I’m not a fan of the multiple break down points of the vacuum systems. I’m sure if the technology was more available in 1970 the headlights would not have been vacuum powered. I’m pretty familiar with the head light vacuum trouble shooting and based on all the possible areas of breakdown, I’m not surprised that it very well is a leak. If the reservoir tank fails testing, I will be changing to electric simply based on how big of a pita to take it out. If it’s any other component I’ll probably just repair it this time but electric will be on the wish list. Anyone ever done the conversion? I’ve seen a kit on eBay for about $400 that looks interesting.
Last edited by Bluesting70; Jul 20, 2021 at 07:46 PM.
you do not need a vacuum tank except for running lights with the engine off. another issue constantly overlooked is blockages. in the vacuum relay there is a vent hole that must be free. you see the mud wasp nest in the one on the left? also the large long vacuum hose gets plugged up. when they are free you can easily suck one headlight up or down with lung vacuum. and a human generates about 2 maybe 3 inches of vacuum witrh lungs tops.
you do not need a vacuum tank except for running lights with the engine off. another issue constantly overlooked is blockages. in the vacuum relay there is a vent hole that must be free. you see the mud wasp nest in the one on the left? also the large long vacuum hose gets plugged up. when they are free you can easily suck one headlight up or down with lung vacuum. and a human generates about 2 maybe 3 inches of vacuum witrh lungs tops.
If vacuum systems were so out-of-date and antiquated, why did GM switch from electric headlamp motors in the C2 series to vacuum actuators in C3's???
I think your paradigm of vacuum systems is a bit 'off-base'. But, if you are set on re-engineering your C3 headlamps, have at it. I'm just trying to make your life easier....whether you believe it or not....
If vacuum systems were so out-of-date and antiquated, why did GM switch from electric headlamp motors in the C2 series to vacuum actuators in C3's???
I think your paradigm of vacuum systems is a bit 'off-base'. But, if you are set on re-engineering your C3 headlamps, have at it. I'm just trying to make your life easier....whether you believe it or not....
I appreciate you trying to make my life easier. But I’m having a hard time seeing how relying on a system that has at least 9 different point of possible break down is going to do that better than electric motors. I’m not jumping into electric motors either. For now, I will probably work with the vacuum system but it sure seems like a lot to depend on just to make 2 lights flip up and down. It’s no wonder thousands of c3’s have already been converted.
you just have to realize the vacuum does not move the headlights. vacuum removes air from one side of the diaphragm so air pressure can push the other side to do the heavy lifting. a tiny obstruction will make the lights barely move even though there are no vacuum leaks. i bought the vac relays in the pic i posted. the 2 on my car had the same wasp nests in them. that is 3 of the 4 relays i saw and handled. they can be cleaned out with a 3/16th or so drill bit by hand from under the car. the big diameter long hose from engine to vac tank was also plugged up. long trans dipstick from both ends reamed it out. oh, blow out the vacuum lines first. if you suck on it to see if it is obstructed, chunks of bug nest go down your throat. unpleasant!!
If vacuum systems were so out-of-date and antiquated, why did GM switch from electric headlamp motors in the C2 series to vacuum actuators in C3's???
I think your paradigm of vacuum systems is a bit 'off-base'. But, if you are set on re-engineering your C3 headlamps, have at it. I'm just trying to make your life easier....whether you believe it or not....
And then to electric for the C4 and C5. When did GM move from vacuum powered wipers? 59?
Electric motors were expensive compared to a metal can with a piece of rubber in it back in the day.
I've read several sources saying the vacuum was a bean-counter decision- even though it looks Rube Goldberg's.
Have you done a reliability analysis for failure points in an electrical headlamp system? There are likely as many risk points in the electric motor, alone, as there are in the entire vacuum system. Then you have wiring (much more failure risk than vacuum hose), power source, ground connections, yada, yada, yada.
You are not going to win this 'contest' on 'system reliability'. Vacuum is easier, lest costly, more reliable, and easier to maintain and troubleshoot. Next!!
Electric Vacuum Pumps
