HamadUP

I was thinking about that the past few days, if my engine vacuum is not enough to operate headlight/wiper door/AC .. etc actuators, then is it wise to hook a small 12V vacuum pump instead of the manifold?

The advantage is that you'll get instant solid vacuum as soon as you switch on your car and it will keep sucking with the same power no matter whats your engine's RPM, and secondly, you could operate all your vacuum actuators without running your engine.

What do you think of that?

MotorHead

OK where do you get one ?

HamadUP

a cheap one which is used to vacuum out A/C systems. I see them for around $100.

BillPk

http://store.summitracing.com/partde...5&autoview=sku

They are used for power brakes with a lopey cam.

7T1vette

Just curious... Have you modified the engine much? Does it have a "wild" cam in it? If not, just chase down the vacuum leaks and fix them (much cheaper and more reliable than an add-on vacuum pump). The headlights, etc. worked OK on the car when it was new, didn't it? {Kind of a rhetorical question...but I'm sure they must have.} No reason it shouldn't work now. If you need ideas on how to find/fix vacuum leaks, do a "search" on that topic in the archive...or PM me.

Jeffery73

If your car is stock, the original system should work. If the motor is pretty wild, go for it. I would think the pump should do the job.

Gordonm

I run 9 inches of vacuum at idle with my cam and it works the headlights fine. Unless you have a radical cam you should be OK with the stock system. I do run a Hydroboost system for the brakes. The stock vacuum brake system sucks, pun intended.

noonie

Make sure you still have a check valve in your main vacuum line off the manifold.
When you let off on the gas and decelerate, almost all engines despite what cam you have, momentarily shoot up to over 20" of vacuum and that is enough in conjunction with the vacuum storage tank to operate all vacuum equipment.

...Roger...

You must have a leak the headlights will operate on 5" of vacuum.Each actuator only uses about a quart of vacuum when it opens or closes and then its done...it consumes NO more until it operates again.

BillPk

But the power brake booster needs 14" minimum to operate at peak assist.

HamadUP

Thanks guys for the information

I have a mild cam (comp cams 268H) and I measured the vacuum right at the manifold and it was about 15 inches but the needle was vibrating back and forth about 2 inches, lets say between 14 and 16 inches. I do have a new check valve and filter, but I still got intemitten headlight not opening problems, most of the times I need to keep the engine running for about 5 min. before my headlamps would pop up, if I switch them on with in say 30 seconds after I run the engine, the drivers side would pop out slowly and the passenger side wont at all. And when I close them and trying to re open them up again (even after a long drive) they just wont open unless I wait for another 5 min. or so. I've been told that the vacuum reservoir should have suffecient vacuum to open them up even after shutting the engine off. Do I have a vacuum reserviour leak? the PO did replaced ALL the vacuum lines with brand new ones from Dr. Rebuild, which are very good types of hoses.

I thought I just dont have enough vacuum from the engine, but from what I read here, it seems that there is some vacuum leaking somewhere. I will start chasing that vacuum.

...Roger...

You need to isolate your leak or leaks.You can do that several ways.One way is check each actuator,relay valve and switch to see if they hold vacuum or you can blow into them and see if they hold pressure.
Another way is to pinch off hoses with the engine running going to say an actuator and see if the system works better-if pinching off a hose makes the opposite one work than the one you pinched off is the leaker.