GEDDES AUTOMOTIVE BRAKE MASTER & CALLIPER REPAIRS / REPLACEMENT

MY BRAKE PEDAL FEELS SPONGY. PHONE: 636 7064 Geddes Automotive Auckland service & repair brake calliper & cylinder problems for cars vans & trucks. We fix car hydraulic brakes problems. We supply & fit brake master cylinders, flush & bleed hydraulic brake systems. HOW DO CAR BRAKES WORK? There are various designs but basically this is how most van & car hydraulic brakes systems work. When you put pressure on the brake pedal, that pushes the piston in the brake master cylinder, that in turn forces brake fluid into the brake lines and out to the wheel cylinders (car brake cylinder). If there is a brake oil leak in the brake system then oil pressure could be lost reducing the braking effect. Air could also be being sucked into the hydraulic brake system. Air compresses more than brake oil so reduces the braking effect and gives a spongy brake pedal. Most vans & car brakes have either a power booster in the brake system, often part of the brake master cylinders or more modern cars with ABS brakes have an ABS pump which like the power booster assists the car hydraulic brakes line oil pressure and increases the braking effect. Drum brakes have wheel cylinders (car brake cylinder) with hydraulic pistons that force the brake linings onto the drums. Disc brakes have brake callipers, the piston (or pistons of van & car brake callipers) clamp the brake pads onto the brake rotor (brake disc). Linings and pads when forced against the drum or brake disc cause friction and slows the wheel from turning. CLICK ON THE TYPE OF BRAKE REPAIR YOU REQUIRE:
		Brake Master Cylinder
		Brake Calliper
		Cylinder & linings

SPONGY BRAKE PEDAL

If you have a spongy brake pedal check the brake fluid reservoir to see if the oil level has sunk. If the level has dropped then the oil must be going somewhere — look for oil leaks usually behind the wheels, under the brake caliper, under the brake drum, on the inner side of the tyre, under the carpet behind the brake pedal. If a brake seal is worn out oil can leak out and air can be sucked in.

Some vehicles have a proportion valve. This proportions the brake line pressure so there is equal pressure on the LH side & RH side of the vehicle. If a brake oil seal is failing this can cause brake problems such as a spongy brake pedal.

ABS HYDRAULIC BRAKE SYSTEMS

ABS hydraulic brakes is also discussed on page "ABS BRAKE LIGHT STAYS ON RESET". The ABS control unit is a series of electronically operated valves. These valves should open & close when commanded by the ABS computer. It is very important that the brake fluid is flushed every 3 years at least. The brake fluid oil is deliquescent (means it absorbs moisture from the air). The moisture boils at a lower temperature than brake oil and can cause brake fade. Moisture gets into the ABS valves and brake master & slave cylinder pistons (car brake cylinder pistons)and causes those to corrode and eventually seize. This reduces brake efficiency and also is a cause of unbalanced UNBALANCED BRAKES AUCKLAND brakes. This can cause your ABS light to come on and to fail your WOF.

BRAKE SYSTEM BLEEDING & BRAKE FLUSHING

On non ABS brake systems, brake bleeding is easier than on ABS brake system. If there is air already in the brake system then it is more difficult to force the air out compared to a straight brake flush.

If the van truck or car brakes have ABS then sometimes we need to command the control valves to open to allow the brake fluid and air (if air is in the system) to pass through and be expelled through the brake bleed nipple on the brake caliper or wheel cylinder.

We have 2 types of brake bleeding equipment; vacuum and pressure bleeding.

COST TO FLUSH BRAKES

Straight forward flush from $69.00 + GST

Depending on the type, make, model & year of your vehicle, depends on what parts are required. Once we have diagnosed the brake problem we can advise the options and costs for your ABS & hydraulic brake repair fix.