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Abs

Why does ABS only work when under wet conditions i.e. wheel-lock. Why not run it all the time, even on dry roads, to stop better (apart from the vibration)

It does, just most people won’t push the brakes hard enough to engage it.

ABS is active all the time, not just when it’s wet.

If you slam the brake pedal hard enough on a dry road the ABS will activate to prevent wheel lock, just like it does on a wet road.

It’s hard to force yourself to hit the brakes hard enough, but if you really slam them, as you would in an emergency, the ABS will work.

It Works When It’s Dry! The ABS Has No Feelings For Moisture, Only Loss Of Traction.

CSA

The purpose of the ABS is to PREVENT WHEEL LOCK; on dry pavement the wheels normally do not lock. You seem to be confused about the reason for having ABS, which is a safety device to prevent wheel lock an allow you to stop straight on a slippery surface.

If you brake very hard on dry pavement, and try to lock the wheels, the ABS will activate and let the wheels rotate.

Hope that explains and answers your question.

Because there isn’t a skid about to happen. If you want it to work all the time, you have to stomp the pedal hard and it will work. Nobody will recommend that you do that. You’d wear it out and you wouldn’t know exactly where you would stop.

Wow McP, How Did You Beat Me? We Both Show 6:59:27PM.
CSA

Part of the correct answer is that ABS is NOT intended to help you “stop better”.

In reality, ABS is designed to allow you to retain the ability to STEER your car while applying the brakes very hard.

Without ABS, a very hard brake application (with or w/o wet conditions) can cause your brakes to “lock”. Locked brakes make it impossible to steer around obstacles such as another vehicle. So, ABS is designed to allow you to apply maximum pressure to your brake pedal while simultaneously allowing you to retain the ability to steer the vehicle away from danger.

As has already been said, ABS is active at all times, but unless you apply the brakes very hard, you are unlikely to be aware of it. However, if you are under the impression that ABS allows you to stop your car in a shorter distance you are wrong.

Hyperspace.

Amazing how fast !! Thank you for the speedy answer !

But now my next question. I have a 1975 2-ton truck with drum-brakes. Installing disk-brakes is too expensive. Is there a device / method to intermittently brake / stop / brake etc… at 10 times / sec and use this all the time, instead of complicated measuring wheel-lock like an ABS ?
I think part of the answer is that you would have little control over how much you wanted to stop, ie pretty much slam on the brakes all the time
OR… is there something to improve drum-brakes ?

Thanks a million for the trouble ladies and gentlemen

Jules Nijst

No

Agree with VDC; even if something was available, don’t bother retrofitting a 1975 vehicle. It simply is not worth it.

FYI Jules, We’ve Had ABS Discussions, Before.

I get the feeling that many experienced drivers who grew up without ABS, don’t care for it. I have it on some of our vehicles and I don’t like it during our long winters.

Others like it, particularly newer drivers who began driving with it on all their cars.

I personally wouldn’t try to get it installed on any of our vehicles with conventional braking.

Put your money into some really good tires, instead.

CSA

I have a '96 vehicle with rear-wheel ABS and in 13 years I have never known them to operate, which is fine with me. I used to have a pickup with 4-wheel ABS and when going over a hump in the street, going down hill, and I would have NO brakes for about 3 feet. That I didn’t like.

I Agree. I Don’t Like That, Myself. When I First Read That ABS Was Coming Out And It Was Going To Be The Biggest Advancement In Safety, Ever, I Was Excited.

However, after using it, I don’t think it’s for us. I think it’s for making new drivers, and other drivers who shouldn’t be on the road to begin with, safer.

CSA