Parking on an Incline [Merged]

[finchy18]

sa matic pwde na P yata kahit 45 degress nka park kasi designed for Parking talaga ang P sign. hehehe.joke kapag sakin sa manual ko okey cguro kpag nka first gear on or nka hand break. i dont know if nka stress ito sa baby ko.

[StraightSix]

mayroon pa break adjuster to keep brake shoes fit

http://auto.howstuffworks.com/drum-brake2.htm

Alam ko ang adjuster Tingin ko lang hindi tayo magkaintindihan ...

When I seconded GlennSter's opinion that the stress is on the handbrake cable, it meant the most stressed part when parking on an incline and I'm sure that's what he also meant. Of course there is also stress on the brake pads, and on other parts for that matter, but not as much as on the cable.

Even if you assume a ratio of 1:10 (very conservative) for the sectional area of the cable vs. the area of brake pad, the force on the cable will be roughly 10x than on the same area on the pad. And that's why I explained that stress is force per unit area, to emphasize that stress is related to area.

[scarab]

..incline garage namen before. nanikit yung handbrake, ayaw bumaba nung oto after releasing the handbrake, so pinwersa ko. had it checked afterwards buti walang na-damage sa preno. only happened once.

[miluku]

thank you.. =) hay.. i still prefer manual.. la pa ako tiwala talaga sa matic.. tulad kanina.. ganun na naman.. biro mo.. mga 15deg lang.. nag "tuk" na naman nung nag change ako P to D. pano pa kaya kung park mo sya matagal sa pababa na parking sa eastwood.. hahahaha!!!

[oldblue]

thank you.. =) hay.. i still prefer manual.. la pa ako tiwala talaga sa matic.. tulad kanina.. ganun na naman.. biro mo.. mga 15deg lang.. nag "tuk" na naman nung nag change ako P to D. pano pa kaya kung park mo sya matagal sa pababa na parking sa eastwood.. hahahaha!!!

just trust the P shift even if you are parked on a hill ... the rolling is normal after P bec. it is engaging the notches of P-break mechanism. if you're moving out naman, the sound you hear from P to D, is just the disenganging of the notches.

http://auto.howstuffworks.com/automa...smission12.htm

[oldblue]

Alam ko ang adjuster Tingin ko lang hindi tayo magkaintindihan ...

When I seconded GlennSter's opinion that the stress is on the handbrake cable, it meant the most stressed part when parking on an incline and I'm sure that's what he also meant. Of course there is also stress on the brake pads, and on other parts for that matter, but not as much as on the cable.

Even if you assume a ratio of 1:10 (very conservative) for the sectional area of the cable vs. the area of brake pad, the force on the cable will be roughly 10x than on the same area on the pad. And that's why I explained that stress is force per unit area, to emphasize that stress is related to area.

assuming *mazdamazda's car is an automatic, there are two stress points.
the parking break mechanism & the emergency break cable-triggered locked drum brakes.

from here http://auto.howstuffworks.com/automa...smission12.htm


The output of the transmission: The square notches are engaged by the parking-brake mechanism to hold the car still.

when *mazdamazda shifts to P, the parking brake mechanism engages/locks the notches of the output shaft. therefore 1st stress point.

when *mazdamazda activates the emergency brake, the cable triggers
the brake shoes to lock the circular drum brake with another help from break adjuster. see link of break adjuster. the drum brake on each of mazdamazda's rear wheel locks as 1 unit drum brake (in each rear wheel). therefore, 2nd stress point.


assuming *mazdamazda's car is a manual, then the the 2 drum bakes on each side are the lone stress point coz there is no P-break mechanism (for automatic) in manual.

am not really familiar with force per unit area = stress. but I did pinpoint 3 stress point area for automatic (2 drum brakes & 1 P-mechanism), 2 stress points for manual (1 drum brake).


that's why I'm not really convinced that the handbrake cable is the most stressed when parking on an incline. it's just like tying *mazdamazda car with the same cable to a tree when parked in incline, and all of *mazdamazda's car weight is held by the cable alone, coz as you said it's the most stressed part. it's not realistic. I believe the cable is used to trigger the locking mechanism which is the drum brake system.


but I'm still confused, if drum brakes are locked, then forces cancel out.
what keeps *mazdamazda's car from moving down the incline?

perhaps, it's the tires (the real wheels in particular) that is the most stressed. the tire's traction with the inclined pavement. the newer the tire the better the traction, the older, the greater chances of skidding (coz of the absence of friction between the tire and the pavement).

am still not convinced with this theory though hehehe

but I did learn something new today, automatic transmissions are safer to park in incline position than manual ones, coz of dual-locking mechanisms. (the P-break mechanism & emergency brake).


of course, manual ones can shift to 1st gear but there is danger when it gets accidentally hit by another car. automatic cars with P-break mechanism are independent of the gears, coz it locks the output of the transmission.

[Psalm136:2]

ang isang suggestion sakin specially if yung sa bangin banda, like sa tagaytay...

pull the handbreak release brakes etc... then pagpatay mo ng engine tsaka mo ipasok sa 1st gear, just to make sure na hindi gagalaw ang car..

ang prob nito eh tulad nung sabi sa isang thread, pag nabangga ka buong makina mo sira

Ito rin po ang ginagawa ko. Pag nakapark ako upward incline, I shift the gear to 1st + handbrake. Pag downward incline naman, naka reverse ako + handbrake. Turo ng tatay ko.

Diko alam na posible palang masira ang makina pag ganito.

[StraightSix]

it's just like tying *mazdamazda car with the same cable to a tree when parked in incline, and all of *mazdamazda's car weight is held by the cable alone, coz as you said it's the most stressed part. it's not realistic. I believe the cable is used to trigger the locking mechanism which is the drum brake system.

Like I said, there are multpile stress areas. The analogy of tying it to a tree is cute but misleading. I was limiting my arguments to the cable vis-a-vis the brake pad/drum statements we made. But since you're not familiar with the math aspect of stress (not that I'm an expert on it) I feel that I have to stop here.

We all learn something from discussions like these, and it's much appreciated from my end.

[bhongskie]

tama si sir MBT, ako rin ganun :-)

NOTE step on foot break, gear to neutral (N), engage the handbrake, let go of the foot brake, then slide it into park (P).

Parking: Foot Break, Hand Break, Gear
Moving: Foot Break, Gear, Hand Break

Essential for passing licensure test in UAE, he he he....

[cutedoc]

solve na ako sa
parking : foot brake, N, P, hand break
moving : foot brake, hand break, D or R