just curious...opinions on downhill braking

[pudman]

I live in a town with lots of hills, and was curious as to the best way for using brakes when going downhill. With an AOD tranny is it better to apply constant brake to maintain a constant speed of lets say 30 mph, or using no brakes to 40-45 mph then brake to 30 mph let off to get back up to 40-45 then brake and so on

 

[5.0Torx]

As a man who loves his manual transmissions, i HATE it when peope just hold the brake down a hill. In my eyes, the brake lights are meant to warn someone behind you when youre about to stop. So if you give it 15% brake pedal, and that trips the brake lights, the guy behind has no way of knowing when a little kid jumps out in front of you and you slam on the brakes to STOP. That few tenths of seconds can mean alot.

When i drive an auto, if the hill is steep enough, ill manually put it inot a lower gear. If not, ill brake below the speed limit and then let off. This oscilates around the speed limit.

Maybe im a purist...

 

[Mustang5L5]

I'd ride the brakes down if it was me. Either way is going to heat the brakes up nice and hot if you ride them down or just slam on them at the end. Aftert you stop though, try not to rest your foot on the brake pedal too hard as this is where pad friction material transfer takes place and your rotors "warp"....especially with stock fox brakes.

If your AOD has a cooler, you could downshift to 1 and use that to help slow you down the hill, but i always say brakes are cheaper than clutches/transmissions

 

[pudman]

As a man who loves his manual transmissions, i HATE it when peope just hold the brake down a hill. In my eyes, the brake lights are meant to warn someone behind you when youre about to stop. So if you give it 15% brake pedal, and that trips the brake lights, the guy behind has no way of knowing when a little kid jumps out in front of you and you slam on the brakes to STOP. That few tenths of seconds can mean alot.

When i drive an auto, if the hill is steep enough, ill manually put it inot a lower gear. If not, ill brake below the speed limit and then let off. This oscilates around the speed limit.

Maybe im a purist...

I see your reasoning here and agree 100%. I never thought about the view from the guy behind. I guess the main reason I asked was which method will wear out the brakes the quickest? A few short hard brakes or one long easy one.

 

[THOR74]

A definite +1 on NOT resting your foot on the brake pedal after hard/long braking. If you do this (squeeze really hot rotors) you can actually contibute to rotor warp, which will screw up your stopping power.

Whether it's an auto or a stick, I usually try to slow down as much as possible before the hill starts, shift down into the next lower gear, and try to let off the brakes here and there in an attempt to let them cool as much as they can. At the bottom, I'll come to a stop and get off the brakes. In an auto, this is easy since you can shift into Park and the car will stay put.

I go even further and try to take it a little easier on the brakes until they have cooled off enough after hot/heavy braking. My rotors last forever. People I know can warp their rotors in no time.

 

[pudman]

makes good sense about the heat and warping rotors. Does heat have any effect on the longetivity of the pads?

 

[bgoins]

i say don't engine brake unless ur brakes absolutely cannot handle it. brakes are made to wear and relatively easy to replace, but engines, clutches and transmissions...not so easy to replace

 

[spoulson]

I once had a scare with brake fade when coming down a hill around Ithaca, NY in a beater '86 Delta 88. I rode the brakes down this hill and was barely able to stop in time for the stop sign at the bottom. I was young and didn't realize that downshifting would've really helped me out.

I can see the logic behind braking and coasting, but it's a safety issue for drivers around you to keep changing your speed.

Next time, try opening the door and sticking your foot out.

 

[NIKwoaC]

I agree with the rotor warping statements above, but I've always been taught to downshift to save the brakes when driving in hilly areas. AODs have low gears specifically for driving on hills, so I don't know why that would be hard on the trans. As for stick cars, I've ALWAYS downshifted during braking without any clutch issues, but of course I live in Indiana and the whole state is one big, flat corn field.

Also, IIRC the EECIV has a fuel-saving strategy during engine braking, so there might be some MPG benefits to down shifting, but don't quote me on that one.

 

[pudman]

Next time, try opening the door and sticking your foot out.

I like this method, but if only I was Fred Flintstone. In the stang it's a no brainer being a 5 speed, but this is my new DD... a '98 escort. It has a low gear, but it is so rediculously low I can go maybe 15 mph at way high RPM's. It's like granny low in a 4 X 4. Can't understand what was going thru Ford's mind when they did this

 

[Mustang5L5]

nothing wrong with engine compression braking a manual transmission if the downshift is rev matched. i have seen guys just let the clutch out without matching. when i downshift i rev up u the correct rpm of the lower hear and let the clutch up fast. you would never feel a thing in the down****

Posted via Mobile Device

 

[mob]

As a man who loves his manual transmissions, i HATE it when peope just hold the brake down a hill. In my eyes, the brake lights are meant to warn someone behind you when youre about to stop. So if you give it 15% brake pedal, and that trips the brake lights, the guy behind has no way of knowing when a little kid jumps out in front of you and you slam on the brakes to STOP. That few tenths of seconds can mean alot.

When i drive an auto, if the hill is steep enough, ill manually put it inot a lower gear. If not, ill brake below the speed limit and then let off. This oscilates around the speed limit.

Maybe im a purist...

Brakes are meant to show the person behind you that you are slowing down. If you are coming up to a turn or going down hill you should be able to hit the brakes to slow your vehicle down without the person behind you getting pissed. If you are not coming up to a red light or a stop sign and the person in front of you hits the brakes you should know he is just trying to slow down and not stop there for you do not need to slam the brakes. If the kid DOES jump out in the street and that person needs to slam on there brakes in my opinions its better for you to rear and that person then for that person to hit the kid. If I need to slow down for a turn or downhill I will ease on my brakes and if the person behind me feels it necessary to slam the brakes he is either a retard or shouldn't be following me that close. It would be worse in my opinion if the person in front of me is slowing down by engine braking and I have no idea because I see no lights in front of me. I pay more attention to the road than to hit someone like that but i can imagine someone playing with there ipod, and the person in front of them starts downshifting to slow down, the person playing with there ipod has no idea they are slowing down and runs into them.

In an automatic I dont think you should downshift at all. If you feel the need to, then upgrade your brakes. In a manual, I never downshift under 3rd gear unless I have to stop a lot sooner than expected, 1st gear though? No way.

 

[THOR74]

To address a previous question, excessive heating of the brake pads caused by extreme braking can leave them "glazed" - a condition whereby the surface of the pads gets, for lack of a better term, 'cooked' from the friction heat leaving them, well, glazed over and not in the state that they should normally be.

Glazed pads will not provide as good braking performance and, in more extreme cases, the glazed surface becomes so hardened that they no longer wear away like they should, but rather end up gouging the hell out of the rotors, often wrecking them.

Regarding downshifts in an automatic - if the tranny has an overdrive gear then shifting into Drive is not a problem on downhills (usually the owner's manual even recommends or at least authorizes it). For a car without overdrive, shifting from Drive down into 2 will often produce a more pronounced relative engine braking effect than going from OD to D, and thus should only be used in truly appropriate situations (and is allowed in such cases).

With a stick shift, as has been mentioned, failure to match engine and tranny speeds during downshifting will prematurely wear away the clutch.

Practically speaking, I would only downshift in any car where I honestly felt that, due to brake fade caused by riding them all the way down a hill, my ability to safely stop the car would be actually compromised (a real rarity in my part of the world).

 

[cusp]

nothing wrong with engine compression braking a manual transmission if the downshift is rev matched. i have seen guys just let the clutch out without matching. when i downshift i rev up u the correct rpm of the lower hear and let the clutch up fast. you would never feel a thing in the down****

Posted via Mobile Device

+1. Thats how I down shift. Rev matching. Depending on the speed limit of the hill and how steep it is, I will use either 4th or 3rd. Hardly ever have to touch the brakes. On my Auto, I will turn off the OD or select 2nd depending. Works good. Hasn't caused any problems and I don't have to ride the brakes.