[Sutripta]

^^^^
Are they using an ASIC for all the telltales then?

Regards
Sutripta

[Hashim]

At the base of hand brake lever (covered with plastic housing) there is a switch which is pushed by hand brake lever when it is pulled up and glows the hand brake light on dashboard. This switch may be jammed and hence continuous hand brake light.

Since the light works on (-ve) feed of 12v which it gets from hand brake switch, there is also a possibility of this switch wire (its a single wire) damaged and touching bare metal causing the light to glow.

[sumannandy]

Please get it checked as soon as possible. I ignored the handbrake light on the advice of a local garage and the brakes failed.

[SDP]

Thanks a bunch guys for pouring in with the replies and suggestions.
I checked the car today morning for brake-fluid and it had indeed dropped. Took the car to a trusted mechanic, bought a bottle of DOT3 and topped up. The indicator stopped glowing immediately. The mechanic expressed a concern about the level of drop and mentioned that there is a high probability of having a leakage somewhere. He suggested that I drive for next 3-4 days, keep a track of the brake-fluid level and revisit if the level drops again.

If there is a leakage, what are the potential areas where it could be (the brake cylinder?) and any experience on what could be the repair costs?

Thanks a lot everybody. Would update the thread around Monday, based on any new developments.

PS : Have a Sunday trip to Pune planned, but most likely I would take my sis's Figo rather than my car till this issue is completely resolved.

PPS : Feeling stupid for not referring to the owner's manual.

[rajeev k]

If the hand brake is fully disengaged, check for brake fluid level in the master cylinder fluid reservoir. If levl is OK dont worry, driving the car won't be unsafe.

If level is low, there may be a leakage from any of the wheel slave cylinders, in which case don't run the car. SOS your friendly mechanic.

[jeeva]

Originally Posted by rajeev k

If the hand brake is fully disengaged, check for brake fluid level in the master cylinder fluid reservoir. If levl is OK dont worry, driving the car won't be unsafe.

Isn't the parking (hand) brake, cable actuated?
As SDP had mentioned earlier about the issue with the rear brakes, I feel the brake cylinder bushes would have given up and started leaking.
A TVS Girling brake cylinder kit costs somewhere in the range of 300 bucks.

[sgiitk]

Please check. Your fluid level may be low. The same light is used for everything. Just call it a Brake Warning Light.

[Jeep]

Potential areas:

Look under the car - Look inside the wheels. If there is brake fluid leakage due to faulty wheel cylinder, you will find it there. The cost of a wheel cylinder for a M800 was around Rs 350 or so. Replacement cost (Labour) was Rs 150. Hence, it cannot be more than Rs or so for an Alto

Also, check the area around brake booster as well.

Originally Posted by SDP

If there is a leakage, what are the potential areas where it could be (the brake cylinder?) and any experience on what could be the repair costs?

PS : Have a Sunday trip to Pune planned, but most likely I would take my sis's Figo rather than my car till this issue is completely resolved.

[V-16]

Originally Posted by SS-Traveller

Does the Alto come with sensors to indicate brake pad wear? In fact, which Indian car does?

I dont know how it works, dont think its sensor based and then again maybe it is but in the Swift as well as in the Santro, when the brake light came on continuously, the pads needed to be changed.

[JustCause]

Originally Posted by V-16

I dont know how it works, dont think its sensor based and then again maybe it is but in the Swift as well as in the Santro, when the brake light came on continuously, the pads needed to be changed.

If the pads wear out excessively, the caliper has to cover a greater distance so that the pads make contact with the disk. Therefore, more brake fluid is taken into the brake system, and hence, the fluid level in the reservoir drops gradually till the float sensor on the reservoir cap completes the circuit and the light glows.

IMO, there are no separate sensors for brake pad wear in the ALTO. One has to rely on looking out for the typical screeching sound on braking as an indication of brake pad wear.

[SS-Traveller]

Originally Posted by V-16

...in the Swift as well as in the Santro, when the brake light came on continuously, the pads needed to be changed.

Explained very well by JustCause - this is usually pre-empted by the brake fluid level being topped up at every service, but yes, if the brake fluid was never checked, and the pads wore out completely, there is a possibility that the light would come on.

OTOH, when brake pads are replaced, there is usually an overfilling / overflow of brake oil from a topped-up reservoir, and about 30-40ml needs to be drained out carefully (without getting it all over the paintwork - I usually do it with an old hypodermic syringe! )

Originally Posted by JustCause

...more brake fluid is taken into the brake system, and hence, the fluid level in the reservoir drops gradually till the float sensor on the reservoir cap completes the circuit and the light glows.

IMO, there are no separate sensors for brake pad wear in the ALTO. One has to rely on looking out for the typical screeching sound on braking as an indication of brake pad wear.

Indeed, that is the sound of the brake wear indicator, which is a strip of metal that contacts the discs when about 2-3mm of brake pad material remains.

[SDP]

Originally Posted by JustCause

If the pads wear out excessively, the caliper has to cover a greater distance so that the pads make contact with the disk. Therefore, more brake fluid is taken into the brake system, and hence, the fluid level in the reservoir drops gradually till the float sensor on the reservoir cap completes the circuit and the light glows.

IMO, there are no separate sensors for brake pad wear in the ALTO. One has to rely on looking out for the typical screeching sound on braking as an indication of brake pad wear.

@JustCause, thats a fantastic explanation. Thanks.

I have a doubt here. In the case that you described (brake-pads wearing out), would the brake-indicator glow only during hard braking because of the temporary drop in brake-fluid? In a way, with brake-fluid topped to normal levels, a indication of brake-pad wear would be the indicator glowing during hard-braking. Is that a correct deduction?

How much do the brake-pads cost? Should I get them replaced proactively?

[JustCause]

Originally Posted by SDP

@JustCause, thats a fantastic explanation. Thanks.
....
How much do the brake-pads cost? Should I get them replaced proactively?

It would initially glow on acceleration & while doing good speeds because of the design of the reservoir. Under acceleration, all of the fluid will go to one end & if that is enough to complete the float sensor circuit, the diagnostic light will glow. Regardless, the intermittent glowing of this light should never be ignored/ dismissed as a faulty hand brake switch.

I got the fluid level topped up last service >4 months and my pads are holding till now. You had also mentioned that the braking is not affected. So, you can get them replaced when you have the time. A set of BOSCH brake pads cost Rs.600 at MASS.

[Sutripta]

Originally Posted by SDP

In the case that you described (brake-pads wearing out), would the brake-indicator glow only during hard braking because of the temporary drop in brake-fluid?

Hi,
Brake pads don't really retract. JC's explanation of light coming on under hard braking is correct. As an academic exercise, see if it comes on on a steep incline, nose down.

Regards
Sutripta

[SDP]

Update :
Have driven very cautiously since last 4-5 days. Have been checking brake-fluid level on a daily basis since last top-up. Have been carrying the bottle of DOT3 bought last week. Traveled around 280 kms yesterday. The indicator did not glow even once. But, today morning noticed that the brake-fluid level has actually dropped noticeably. The level is not close to the 'Min' mark, but has definitely dropped by 5-6 mm since the top-up. So looks like there is definitely some leakage. Would take the car to the mechanic tomorrow and update. Thanks.