Q1: I have a 2009 Toyota Camry. Recently, I felt the steering wheel vibrating every time I brake at a speed of, say 120kph-130kph. It occurs only when I brake at high speeds.
At every service, I always have alignment and balancing done. What is causing the steering wheel vibration and is it dangerous?
Lee
Kajang
This is what we called “brake juddering”.
This happens because of thermal expansion or the wearing out of your brake disc is not even.
That’s why when you brake, it vibrates. Sometimes, the cause is the brake pad material and sometimes a hard object which has been inserted between brake pads and brake disc which cause uneven wear to the rotor disc.
There are two types of brake judder: hot judder and cold judder.
Hot judder occurs when the materials of the rotor disc expand unevenly during thermal expansion and the only remedy is to replace the rotor disc.
Cold judder is when you feel the vibration even when applying the brakes at low speed; this is caused by uneven wear in the disc. The remedy for this is “re-facing” or machining if the thickness of the disc is still within the limit.
In your case if it only happens at high speed this is hot judder so the only remedy is to replace the rotor disc with a new one BUT to make it sure it is hot judder, the rotor disc must be measured first at 12 points to check the evenness of wear.
To your last question, this problem is not dangerous and has no effect on braking safety.
Q2: In a previous set of answers, TOC offered an answer to keeping rats away from a car.
Other than keeping the surrounding clean of food waste to prevent rats from eating and hiding inside the engine compartment, what other methods can be used to prevent them from encroaching into the car if we are forced to park in an allocated parking lot such as in apartment blocks and the said parking lot is near the refuse chambers?
Are there any chemical or audio/ultra high-frequency device that can be used to keep rats away?
CK Siow
Kuala Lumpur
When we say “keeping the rats away from the car”, it only means one thing: we need to clean our surroundings because that’s the reason why rats are encroaching into the car.
if you know where the rats passes through when entering your engine compartment, get coconut husk brush and tie some along the route rats take to the engine compartment. Alternatively, any mice repellant will do.
Q3: I have discovered for the past few months that my 2005 Kenari air-conditioner gets warm especially during traffic jams. Once the car starts moving again, the cabin air becomes cooler.
At night, when the car is stationary for a while, the air-cond air is not as cool as when it’s moving.
I had the air-cond checked; there was no leakage or lack of gas.
I even had my radiator flushed and cleaned. The radiator technician told me the rest of the cooling system is fine, even the blower fan.
As a temporary measure during hot days and when stuck in traffic, I'll pop the bonnet open a little to ensure more air goes into the engine and help make it and the air-conditioning parts stay cooler.
But I want a permanent solution. Can you help?
Hot Kenari Owner
Penang
It is obvious that the problem is insufficient air passing through your condenser. It’s either your condenser is clogged or your condenser fan motor is not working properly or rotating slowly.
The solution is to make sure that your condenser is cleaned and flushed with water.
Also check the fins of the condenser are not bent or else air would not passed through properly.
How many radiator fans does your car have?
Some have two. One is for the condenser and the other is for the radiator.
These two work together once the temperature is rising. These two motors must be checked to ensure they work properly.
They may be working but slow, so the condenser is not getting enough ventilation at high temperatures.
