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-   -   Please Guide Us: How to stop a car that has lost its brakes (https://www.team-bhp.com/forum/technical-stuff/16368-please-guide-us-how-stop-car-has-lost-its-brakes-2.html)

Shifting the vehicle or taking it down on first gear is really not necessary, second with lilght brakes do good. In case of emergency first is good. what happens when the vehilce is shifted to first gear is that there is a huge deceleration that takes place, This can cause damage to the vehicle and may be to the rod as well.

In geared vehicles, down shifting gears at regular speeds will help slow down the vehicle from higher speed with loss of brake power. You can also use handbrakes in automatic vehicles to stop, they are all cable operated and not dependent on the normal brakes. So loss of hydralics with leaks of oil should not affect the hand brakes. Put take care not to pull it hard, do it slowly and the vehicle should slow down.

Most of it all, dont loose yourself, you will still survive if you have the presence of mind. Think and act, dont hurry unless in dire situations. I drive an Alto Lxi and tried kind of emergency stops without the brakes, using gears and handbrakes. But in realy emergeny how i will react, I really dont know... time will tell, but I hope I never have to do it.

Most cars usually keep 2 different brake circuits; in case of a fluid leak, one of the circuits should assist in emergency. All you can do is this- if the brake pedal becomes mushy, don't pump it. Pumping means more fluid loss. Pull the handbrake, maintain steering control, and downshift, bringing the engine RPM as optimal as possible. Once you're into 1st gear, just switch off the engine. Don't use the clutch.

@RKS; Your Dad probably meant the propeller shaft or the rear axle shafts. It does happen, when excessive jolt/torque is transmitted at once. Remember old Ambys...

In those cars, there were no synchromesh gear boxes which is why you could only try stunts like changing down to first gear by using what was called "double de-clutching"...even that would not be foolproof in Ambys & Fiats and you could end up having broken gear pinions etc.

In most modern day cars, gearboxes are synchromesh so you can engage first gear on the move with no fear of breaking anything

Guys, I think the original topic refers to automatic transmissions.

Even I'm curious to know what to do if I'm ever stuck in such an indesirable position. We all know what to do with manual shifts, but autos sound quite helpless.

Hey,

You might want to add a certain speed factor to it. If you shift into 1st gear at say 100km something is bound to get busted. Like Heel 'n Toe's advice a little bit of common sense is also needed. What I suggested was obviously to be tried on a open empty stretch of road only.

Viper

Come on Viper, I'm talking about a reasonable speed....I think anyone who's been driving for a while will not try to change down to 1st at 100 kmph...i think RKS was referring to a 1960 Fiat where chances were it would have broken if you tried it at 25-30kmph...........whereas in a modern day vehicle, you could probably do it at close to double that.......please read my post as a reply to RKS only

@rks

You can't shift to first directly; you need to slow it down gradually..

If you're in 5'th; say... you need to shift to third, then 2'nd and so on..

Wait for the revs to drop until you are able to shift down again, shifting directly to first is going to probably break enough parts even on a new car to let the car free wheel...

I believ damage to vehicle would be last thing on your mind & all you would worry would be your own safety.

Btw if we are at high speed shouldnt we shift down gradually than directly to 1st I mean the rev would go much high & it would be way to jerky than gradual shifting.

As about Automatics I dont think there is much beyong hand brakes Btw cant it be put to parking mode ? would it be similar to putting in a lower gear just curious ??

@pastmaster: your procedure is OK for normal operation. But in a brake-failure emergency where you absolutely need to stop quickly, you might want to consider going directly to second if speed is below, say, 80 kmph, and then to first once the speed drops to about 40-50 kmph. You are still risking some damage, but this is an emergency.

@veyron1: yoiu are probably right. My dad did mention some rod/shaft breaking if one went downhill in first, but I don't recollect exactly what he said -- all I remember was that he was very agitated when I was making the move to go downhill in 1st (long, long ago).

Thanks for your reply. My Santro manual specifically warns of possibly serious damage if second gear is inadvertently engaged while shifting from fifth to fourth. But it doesn't mention any specific maximum speed at which second can be engaged. My guess is 80 kmph -- maybe pushing my luck a little here.

In automatics, if the brake fails ( the main ones) here is what to do - move to the lowest gear, take ur foot off the pedal and then once speed is lower , move back the gear lever to neutral and then jam it into P or park - u will probably get a huge jolt ( so seat belts are a must) - u will have to push the small knob on the automatic to move past the Reverse mode but the car will stop - if hand brakes are working - try putting those on as well but only after u have reduced speeds
This has worked for me - in the sense that I tried it out - rather than have a real brake failure

If you wanna survive.....and live to tell the tale....AND not worry about the car....

Drive it into a lake!!!!!!!!!!!!!!!!!!!!

(and hope u know how to swim)

Otherwise use ur gear box with a bit of handbrake...and scrape it against the side banks on the road or a wall!!!!

Just a matter of who you love more!!!! (Yourself or your car!!!)

OK... The procedure is this,
DO NOT Panic
Shift judiciously to the lower gear, take of foot from clutch allow the car to slow down.
When slower enough pull the hand break slowly so as not to loose the cable,

In an event the hand break is also failed switch of the engine! So that the engine breaking is provided till the car comes to a halt.


I thoought of this crazy situation after driving my friends Wagon R, and compared it with my Petra..

A wagon R and many other cars have following positions on the key lock.

Off: Engine is off, accessories off, Steering is locked

ACC: Accessories are switched on but not the ignition

ON: ACC+ engine Ignition is ON

Start: a non latching position which is used to crank the engine

In a Fiat car...

Park: U can not go to this position unless you press and hold a little button near the key and turn the key. Actually turns on the parking lights. This is useful as the electricals go off when you switch off the key in FIATs

Lock: Normal position where you switch off the engine. No accs work, no Ignition. Steering is locked.

MAR: ACCs work Ignition work

Start: Crank the engine


In this case if you choose to switch off the engine, It is very much possible in a wagon R or any other car with similar mechanism without loosing the steering control (without locking the steering). In a fiat, you switch off the engine you locked your steering too:Shockked: .

Well, Today I discovered not really so. You can switch off the engine in lock position..and the steering does not really get locked intill the key is pulled out.

I opened the key stack today to find this mechanism. and it really interesting.

Any ideas why would fiat choose this "different" sequence?