Stay far away from butyl or neoprene rubber which are undependable even with plain water. Other materials used for o rings include ptfe universally noted for its chemical resistance but difficult to install due to minimal elasticity.
Brake Fluid Change Jaguar Forums Jaguar Enthusiasts Forum
Brake fluid o rings. Using an incompatible fluid will also not actually dissolve o rings well unless it is something really evil. It is proof against anything liquid in a car. Mcmasters carr has o rings not made in china and if you run into an oddball size its possible to make your own. It is a loop of elastomer with a round cross section designed to be seated in a groove andor compressed during assembly between two or more parts creating a seal. Dot brake fluid is glycol based and not actually corrosive it does not harm metal in any way but it does react with certain materials for example it damages paint. O ring chemical compatibility chart learn how different o ring materials and chemicals interact.
The o ring in the piston is designed for 5056 fluid. There are build your own o ring kits available. O ring materials compatible with brake fluid select a material to show its compatible chemicals aflas 4 buna n nitrile 1 butyl 4 chemraz 0 epichlorohydrin 1 ethylene propylene 4 fluorocarbon 1 fluorosilicone 1 hypalon 0 kalrez 0 natural rubber 1 neoprene 1 nitrile hydrogenated 3 polyacrylate 1 polysulfide 3 polyurethane cast 1. The problem is that the o rings might swell up. This material is known to display good heat and compression resistance. Ethylene propylene rubber epr o rings.
For the purposes of this article we will focus on just three common rubber types found in o rings and similar automotive seals. Unlike viton o rings ethylene propylene rubber epr o rings are suitable for use with corrosive skydrol hydraulic fluid as well as steam water silicone oils brake fluids and alcohols. Im told dot 3 will call that o ring to swell. So we need to replace the. Grob requires the use of dot 3 fluid because of the master cylinder. O rings an o ring also known as a packing or a toric joint is a gasket in the shape of a torus or doughnut shape.
Buna n viton and epdm. Of all three rubber types epdm is the only one that should be considered for use anywhere in a braking. Basic o ring chemical resistance compatibility information is based on isolated generic o ring material testing in optimal conditions at room temperature and pressure. Water coolants both ethylene and propylene glycol and glycol based brake fluid. Fep encapsulated fep is similar to ptfe and is used to cover viton or silicone o rings to offer the chemical inertness of ptfe with some elasticity.
Gallery of Brake Fluid O Rings
