Power brakes delete

[pete c]

There really isn't a fuel savings to speak of here other than being able to EOC for longer stretches.

I might give the PVC pipe idea a try. Pretty sure I can do it with junk laying around the basement.

[mechman600]

My setup doesn't have a vacuum reservoir. The pump cycles basically every time you stab the brakes. It works very well, but I am going to add a reservoir only to make it more stealthy in parking lots.

This is the first mod I would do if planning to EOC with an ICE car.

You can see how it's wired on the right bottom side of my schematic:

[arcosine]

Just put the car in gear, with the ignition off when you want to stop. It will make vacuum.

[D.O.G.]

Originally Posted by arcosine

Just put the car in gear, with the ignition off when you want to stop. It will make vacuum.

This works well.

I use a maintained ignition kill switch so that I can EOC and still use engine braking down long hills.
A welcome side effect of this is that it keeps the brake vacuum "topped up" for emergency use.

[wolydotmatrix]

Never dawned on me to engine brake to produce vaccum, never too old for the light bulb to brighten. Thanks

[pete c]

I do understand spinning the engine up via the tranny quickly restores vacuum and I do it all the time. It is just that it would be nice to be able to coast long stretches which require occassional brake taps without having to worry about whether or not I have a pump left. As many here already know, you go from full power to nothing very quickly. There have been times when this has caught me a bit off guard. It has never resulted in an accident and I would like to keep it that way.

[ConnClark]

As if you're not a big enough hazard doing EOC you have to try this?!?!!?

[pete c]

My take on the EOCing is dangerous debate.....

EOCing does mean you have some loss of maneuverability with no PS. It also increases the chance of running out of brakes if you do not pay close attention to your vacuum supply (the point of this thread).

But, EOCing takes increased attention to what you are doing. This increased attention helps with the two leading causes of accidents, IMO. Not paying attention and falling asleep.

In my 30+ years of driving, I have found that dozing off from boredom is by far the biggest risk. I have driven tired and in my misspent youth, driven drunk. And from personal experience, I can say tired is far more dangerous that a little drunk. A lot drunk is a different story. So if EOCing means I stay more involved, it also means I stay more awake. So any slight risk that comes with possible loss of brakes/steering is more than offset by the fact that I am conscious.

[PaleMelanesian]

Originally Posted by pete c

I do understand spinning the engine up via the tranny quickly restores vacuum and I do it all the time. It is just that it would be nice to be able to coast long stretches which require occassional brake taps without having to worry about whether or not I have a pump left. As many here already know, you go from full power to nothing very quickly. There have been times when this has caught me a bit off guard. It has never resulted in an accident and I would like to keep it that way.

The way I approach this is, if I've used 2 or 3 pumps (out of 5 usually in my car), I'll do a quick bump-start-key-off cycle to restore it. That way I'm not running close to the edge. I do it when things are nice and clear, so it's not a problem if/when an emergency does come up.

[oil pan 4]

I don't have a vacuum boosted brakes on my suburban, but if I did here is what I would do.
First off I would give the brake booster its own vacuum canister isolated with a check valve. That canister would have an additional vacuum pump plumbed into it with a vac switch set to turn the vacuum pump on at around 14''Hg.
Then I would add a warning circuit, a red light or LED (always hot) that grounds through another vacuum switch set for say 10'' to 12'' of Hg.
That way you always have power brakes or a warning light if you don't.