Looking to source the small o rings that seal the e brake actuating plunger within the rear calipers. Please confirm which o ring material is friendly to brake fluid.
Avid Sram Fitting And Coupling O Rings For Pro Bleed Syringe Bag Of 10 11 5315 053 020 Parts
O ring for brake fluid. 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. Id recommend looking for a replacement from the manufacturer or a good bike shop. Standard o rings will degrade very quickly in dot fluid as it is highly corrosive. 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. On a recent tour on an old and rare bike i had a problem with the seal on the hydraulic clutch. Other materials used for o rings include ptfe universally noted for its chemical resistance but difficult to install due to minimal elasticity.
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. Viton is not recommended. 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. 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. Fluid compatibility guide a detailed list of fluidschemicals with their compatibility ratings for use with the most common o ring materials. 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. O ring chemical compatibility chart learn how different o ring materials and chemicals interact. 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. Nitrile o rings are not advisable for use with automotive brake fluid ketones phosphate ester hydraulic fluids and nitro and halogenated hydrocarbons. 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 discovered that bearing houses and seal companies do not carry o rings made of ep. Many bike shops will have tackle boxes full of specific parts for hydraulic brake systems. Look at the following compatibility list dot 3 is under brake fluid dot 3 glycol type.
Gallery of O Ring For Brake Fluid
