Rebuilt Master Cylinders

That really is an easy one...Master cylinders should not be rebuilt, unless you have the equipment to build one from scratch. This is because of the way they are made. Sure you can buy a rebuild kit for almost any master cylinder and sand out the bore with fine emery cloth, and reassemble it with new seals and snap rings that come in the kit. However, when you get done, you should ask yourself how sure you are that it will hold the close to 2,000 PSI that is in there while the brakes are being used? Good luck with that. See you in a week, at the auto parts store trying to buy as new one, if the car is still in one piece. General rule of thumb : Anything on the hydraulic part of the brake system should always be replaced with new parts, and not 'rebuilt'. for safety's sake.

The reason they should not be rebuilt, is because of the way they are made. The bore, where the pistons go is a special unidirectional 'high pressure' piston bore. The ONLY way this can be done is by pressing a ball all the way through a solid metal block. This is the only way to create the high quality unidirectional bore that is required to hold the GREAT amounts of pressures inside the master cylinder, which is well over 2,000 PSI. There is no way that honing (or sanding) this 'special bore', would be able to hold that kind of pressure. You hone car engine cylinders, where pressures are only a few hundred PSI ,instead of a few thousand (that your life depends on).

With that said...If you plan on rebuilding your brake master cylinder, you should get a good insurance policy, too.... One that also covers the people you will take out with you when you go through a busy intersection, and can not slow down.

Spend the money to get it fixed right, all you need is a new master cylinder, right now. If you try to rebuild it, you will have to replace a lot more than that. Hopefully it's not a life, or several.

Here, I'm going to help you out. Advance Auto Parts always has a sale on brake parts. You can usually get about fifteen to twenty percent off if you pay for the part online, then pick it up in the store. Once you get back with the new one, here is a link to my article about how to go about changing a master cylinder.

Thanks for reading, and stay safe! After all, you cannot put a price tag on safety.