A Happy New Year to everyone… I pray everyone had a good year. This year, we promise to help you make this year a better one.
With some people asking what exactly does one mean when you say a “brake overhaul” or “brake rebuild,” most would say bringing down the disc calipers and changing the O-rings of the calipers or the cups of the brake cylinder. This is usually done when the calipers are either stuck up or the brake cylinder has a leak. When you discover that the calipers are not functioning properly, you also notice uneven disc rotor wear. This usually means a resurfacing job on the disc rotor. Or it is when the brake master has a leak that it is replaced or repaired with a repair kit. Or when you simply replace the worn out disc pads or the worn out brake shoes.
So what does it really mean when you say a brake overhaul? A complete brake rebuild, for me, would be working on the brake master, the calipers or the brake cylinders, replacing or resurfacing the disc rotors or the brake drums, vacuum hose from the manifold to the Hydrovac and replacing the brake hoses. On much older cars, a brake rebuild includes the replacement of the metal brake tube. On diesel engine cars, most systems have a vacuum pump built in to the alternator to supply vacuum pressure and a check valve along the hose to the Hydrovac. On some vans, there is a mechanical proportioning valve. It works by adjusting the brake pressure to wheels when the load in the van changes.
Now, when do you need to change the brake pads or the brake shoes? When does the brake rotor or the brake drum need to be resurfaced? Well, that depends…if the wear on the contact surface is not too deep and it is not warped, then it would be okay not to have it resurfaced. If the wear is too deep or if it is warped, then you need to have it resurfaced. But take note, you are only allowed too resurface up to a certain thickness. But ideally, whenever you change pads or brake shoes, you should have the mating surface resurfaced to ensure a flat surface. A flat surface provides more contact surface between the pads and the disc. This allows better stopping power.
When you remove the disc rotor, you would need to remove also the wheel bearings. Since the unit is already pulled down, inspect them for wear. I would recommend using a waterproof kind of grease when repacking the bearings. For the master brake cylinder, if it leaks, disassemble it and check the bore for wear. If the bore surface is still good, clean it with fine sand paper or a brake cylinder honing stone. This will ensure the surface is clear of scratches. After doing so, you can rebuild it with a good quality repair kit – although some would argue that it would be better to replace the whole assembly. I agree with them but if cost or availability of the replacement part would be an issue, then a rebuild would be alright.
For the brake hoses, some would say you don’t need to change them if they don’t leak. Well, that’s kind of true but if you try and pinch them and they seem a bit hard, they may not be that flexible anymore: a sign that the rubber material has degraded. The rubber could expand and the inner diameter shrink, limiting the volume of brake fluid flowing through it. Or as pressure builds up, the hose might expand. In the course of a rebuild, I would just replace them. If you could upgrade to braided stainless steel hoses, that would be great. You can minimize pressure loss in the brake system. When cleaning or prepping the parts, use a brake cleaner. This breaks down all the oil and dirt and dries fast. Use paper towels to wipe the parts. A cloth rag can leave particles that can damage moving parts. Avoid using kerosene or gasoline to clean the parts. They could harm the rubber parts. Not to be a bit overkill… but even the oil from our hands can do some damage.
When assembling or installing all the parts, apply some brake fluid on the inside. Use only new brake fluid. What brand to use? I prefer to use ATE, Bendix or Castrol or those inside a metal can. But even if you use the expensive ones, you still need to regularly flush your brake system at least yearly, even if you don’t use your car that often. Even the cheaper brands will do, just flush your system regularly.
When installing the brake pads, add a little grease or anti-brake squeal at the back. Mag 1 or OWS have this product. Concorde usually has on stock copper grease. I learned to use this from the dealers years ago. When it’s time to bleed the system, do it thoroughly. I bleed the system at least three times. Adjust the parking brake accordingly. Before you can test drive the car, step on the brake pedal several times. Then take the car around the block and tap on the brakes every so often to let the pads seat on the rotor properly. It would take a few kilometers for this set in. With the engine on, step on the brakes a couple of times until it hardens up. The brake pedal should not sink too much. If it does, double check for leaks and bleed the system again.
As to what brand of brake shoes or brake pads to use… try to get OEM or original equipment manufacturer. The replacement ones are also good, but what brand is hard to say. The materials vary from one brand from another. It may work for one car brand but it may not work for the other.
This work can be done in your own garage. All you need are a set of wrenches, pliers, screw drivers, a jack, jack stands, cross wrench and steel brush. Before you mount the wheels, clean the threads of the mounting bolts. Avoid putting any kind of lubricant. The lubricant will not give a complete metal-to-metal fit along the thread when you tighten the lug nuts.