Michael. 2313 Report post Posted May 24, 2016 Hey lads, Does anyone have any experience with brake fluid and it's compatibility with different seal materials? I've done my fair share of googling but it will be of further benefit to discuss it more. With dot 3, 4 and 5.1 brake fluid I understand most types are a glycol based. Widely available seals are Nitrile 70 (NBR) however this material seems to be "not recommended" or "not suitable" for glycol base brake fluids - but to what extent is what I'm wondering, do the seals perish sooner, or do they just fail within days or weeks of use? Such isn't so clear. Instead ethylene propene (EPDM) seals seem to be the best suggestion for application with brake fluids. The trouble I've found is they are less common and more difficult to get in metric sizes, with only some NZ companies offering them in imperial sizes. Anyone here have knowledgeable insight of such matters? Please share your thoughts! Quote Share this post Link to post Share on other sites
_ethrty-Andy_ 2132 Report post Posted May 24, 2016 isn't this overly pedantic Mike? i would leave it to the manufacturers. if its a master cylinder i trust them to do the research its compatible with brake fluid... Quote Share this post Link to post Share on other sites
Michael. 2313 Report post Posted May 24, 2016 isn't this overly pedantic Mike? i would leave it to the manufacturers. if its a master cylinder i trust them to do the research its compatible with brake fluid... It's more for custom repair stuff, replacing no longer available seals etc Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted May 24, 2016 Have you tried talking to SEAL HOUSE Michael ? Quote Share this post Link to post Share on other sites
tawa 150 Report post Posted May 26, 2016 In a pinch we used nitrile as some dust seals on a brake caliper once. Once. Stick with EP seals unless you want a leaky squidgy mess where your seals used to be. 1 Quote Share this post Link to post Share on other sites
Michael. 2313 Report post Posted May 26, 2016 Have you tried talking to SEAL HOUSE Michael ? Sent them an email. Quote Share this post Link to post Share on other sites
Michael. 2313 Report post Posted May 27, 2016 Discussed it with Seal House, seems they have the right type so ordered a bunch of the seals I need. Brake fluid Glycol based needs EPDM rubber, with a peroxide cure - FDA approved and more expensive. The cheaper ones are sulfur cured and less stable. Cheers for the recommendation Glenn 1 Quote Share this post Link to post Share on other sites
