Ask the Mechanic: Why are my Nissan brakes failing?

Hello Paul, I own a Nissan Terrano whose braking system has failed to work normally since its rear brake fluid tube burst and was fused. The master cylinder and servo have been replaced but the brake system has not got sufficient pressure to push the pads. What else can I do?


Hello Meshack, your Nissan seems to be plagued by a ‘spongy’ brake or ‘no brake pedal’ situation. This usually happens when your brake system loses brake fluid pressure caused by a brake fluid leak or master cylinder failure. The master cylinder is a component that pressurises the brake fluid lines to provide hydraulic pressure, which in turn helps to engage the brake calipers and pads at each wheel. This is how a vehicle stops when you step on the brake pedal.

From your account, trouble seems to have started when the brake fluid lines leaked or ‘burst’ as you described it. Your continued experience of spongy brakes could be how the brake fluid lines were repaired or ‘fused’ as you called it. In case this repair involved gas welding the brake fluid pipes or lines, there is a possibility that the welded pipe may be leaking, kinked or blocked. This will restrict or reduce the pressurised delivery of brake fluid to the rear tyres.

The repaired brake fluid line or pipe should be tested for a leak or replaced with one that is not damaged. The other reasons for failure to get brake pressure after replacing the master cylinder could include reusing aged brake fluid, a wrong brake bleeding procedure or faulty master cylinder. Renew all the brake fluid. Brake fluid should be replaced every four years because it is hygroscopic and tends to attract moisture. This reduces its hydraulic effect as well as its role to prevent corrosion and overheating of the brake system.

Ask your mechanic to consider bench bleeding the master cylinder before installation. Thereafter, bleed the brake lines at all wheels. This will prevent buildup of vacuum, which prevents flow of brake fluid. If all fails, consider the quality of the master cylinder you have bought. Check whether it is a faulty, used or a counterfeit low quality part.

Should I replace the costly Range Rover shock absorbers?

Hello Paul, my Range Rover Sport has of late developed a rattling noise in the front suspension. Should I replace the costly air dampers? I am told they cost an arm and a leg. Robert

Hello Robert, the Range Rover Sport front air suspension is costly because the air bellows come with the shocks. This is a system that automatically adjusts the height of the car by inflating or deflating airbags fitted to the shock absorbers, instead of the ordinary coil springs. When the shocks fail, they tend to make a horrible noise but will also not be effective in dampening the imperfections of the road to smoothen your ride and keep the car stable.

You need a garage inspection to confirm that the front shocks with air dampers have failed and need replacement. However, there are other probable causes of rattling noise in the front suspension system of a Range Rover Sport. These include upper control arm bushes, lower control arm bushes, ball joints as well as stabilizer link bars. These have to be inspected for wear and tear. Get a complete inspection of the front suspension system before you commence with repairs.

How can I replace a lost Toyota Key?

Hello Paul,  I own a Toyota Progress which I have been driving for more than two years. The key got lost and the car is now parked. I fear cutting another key as it may not start the car. I was told that for the new key to start it must be programmed. How safe is this programming and how much would it cost?


Hello Rashid, your Toyota Progress, like many modern cars today has a key with an inbuilt encoded transponder chip. This key is programmed at the factory to be recognised by the car security system modules which issue start authorisation when you turn the key.

A locally cut key will not be recognised by this security system. The best place to start is with the authorised Toyota dealers who can order for a new set of keys and immobiliser engine control unit and programme them to your car. Contact the local Toyota dealer with details of the car and proof of ownership for a quote.

Can I get a new Toyota AE100 engine?

Hello Paul, I have a Toyota AE100 (Kikumi) whose engine consumes a lot of oil and smokes while driving. Is it possible to get a new engine and how much will it cost?


Hello Tony, it is not possible to get a brand new engine for your Toyota AE100. However, you can get a quality used engine imported from Japan. This will cost Shs5m to buy plus the cost of fitting, oil and fluids after installation. These engines are now rare and may have to be bought from a reputable dealer to avoid buying a poorly rebuilt engine passed on by unscrupulous mechanics as an import.

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