Many bike shops will have tackle boxes full of specific parts for hydraulic brake systems. Fluid compatibility guide a detailed list of fluidschemicals with their compatibility ratings for use with the most common o ring materials.
Hollow O Rings In Silicone Viton Amp Nitrile O Ring Cord Nds
O ring for brake fluid. On a recent tour on an old and rare bike i had a problem with the seal on the hydraulic clutch. 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. O ring groove design guides o ring groove dimension guidelines for standard o ring grooves metric o ring grooves jis o ring grooves and other o ring gland designs. Please confirm which o ring material is friendly to brake fluid. Other materials used for o rings include ptfe universally noted for its chemical resistance but difficult to install due to minimal elasticity. Its small about 580 outside diameter with 060 section.
If you buy your brake fluid from pegasus auto racing supplies use epdm seals in that system. I have a whole bag of epdm o rings that are the correct size for the cleveland 300 series brake calipers as used in most ga cleveland brakes with 5606 type mineral based fluid and as used by stemme gmbh wdot fluids. Basic o ring chemical resistance compatibility information is based on isolated generic o ring material testing in optimal conditions at room temperature and pressure. Of these three rubber types epdm is the only choice for seals in braking systems using a glycol based or silicone based dot approved or pure racing brake fluid. I discovered that bearing houses and seal companies do not carry o rings made of ep. Look at the following compatibility list dot 3 is under brake fluid dot 3 glycol type.
O ring chemical compatibility chart learn how different o ring materials and chemicals interact. Nitrile o rings are not advisable for use with automotive brake fluid ketones phosphate ester hydraulic fluids and nitro and halogenated hydrocarbons. Looking to source the small o rings that seal the e brake actuating plunger within the rear calipers. Nitrile o rings which have a temperature range between 54 and 149 degrees celsius are suitable for use with water petroleum oils and some hydraulic fluids. Standard o rings will degrade very quickly in dot fluid as it is highly corrosive. Id recommend looking for a replacement from the manufacturer or a good bike shop.
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. Viton is not recommended. Virtually any size o ring is available off the shelf in nitrile butalene or neoprene but ep needed for resistance to brake fluid is impossible to find.
Gallery of O Ring For Brake Fluid
