{"id":16561,"date":"2026-05-17T22:20:21","date_gmt":"2026-05-17T13:20:21","guid":{"rendered":"https:\/\/tsrjp.com\/?post_type=tips&#038;p=16561"},"modified":"2026-05-23T13:21:46","modified_gmt":"2026-05-23T04:21:46","slug":"blog21","status":"publish","type":"tips","link":"https:\/\/tsrjp.com\/en\/tips\/blog21\/","title":{"rendered":"Brake oil no longer exists!? Dissecting the reasons behind the misconception"},"content":{"rendered":"\n<p class=\"has-small-font-size wp-block-paragraph\">Brake fluid is &#8220;brake fluid,&#8221; not &#8220;brake oil&#8221;!<br>Then why does the term &#8220;brake oil&#8221; exist?<br>Why is it called a &#8220;hydraulic (oil-pressure) brake&#8221; when it is not oil?<br>This time, we will explain the reasons behind it.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"1050\" height=\"700\" src=\"https:\/\/tsrjp.com\/wp-content\/uploads\/2026\/05\/fruid.webp\" alt=\"\" class=\"wp-image-16563\" srcset=\"https:\/\/tsrjp.com\/en\/wp-content\/uploads\/2026\/05\/fruid.webp 1050w, https:\/\/tsrjp.com\/en\/wp-content\/uploads\/2026\/05\/fruid-300x200.webp 300w, https:\/\/tsrjp.com\/en\/wp-content\/uploads\/2026\/05\/fruid-1024x683.webp 1024w, https:\/\/tsrjp.com\/en\/wp-content\/uploads\/2026\/05\/fruid-768x512.webp 768w\" sizes=\"(max-width: 1050px) 100vw, 1050px\" \/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading u-mb-ctrl u-mb-10 has-medium-font-size\">What is brake fluid?<\/h3>\n\n\n\n<p class=\"has-small-font-size wp-block-paragraph\">Brake fluid is, simply put, a type of alcohol.<br>Its main component is &#8220;polyethylene glycol monoether&#8221; (glycol ether for short).<\/p>\n\n\n\n<h3 class=\"wp-block-heading u-mb-ctrl u-mb-10 has-medium-font-size\">Why is it called brake oil?<\/h3>\n\n\n\n<p class=\"u-mb-ctrl u-mb-10 has-small-font-size wp-block-paragraph\">Because the original brake fluid was vegetable oil and looked oily, it was called &#8220;brake oil,&#8221; and the term &#8220;hydraulic (oil pressure)&#8221; was used.<\/p>\n\n\n\n<p class=\"u-mb-ctrl u-mb-10 has-small-font-size wp-block-paragraph\">The era spanned a few decades starting from the 1920s.<br>Specifically, castor oil was used.<br>By the 1940s, a complete transition to glycol-based fluid had occurred.<\/p>\n\n\n\n<p class=\"u-mb-ctrl u-mb-10 has-small-font-size wp-block-paragraph\">By the way, there are other brake fluids besides vegetable oil and glycol.<br>Harley-Davidson used silicone-based brake fluid, but they switched to glycol in 2005.<\/p>\n\n\n\n<p class=\"has-small-font-size wp-block-paragraph\">Citro\u00ebn and MTBs used brake fluid made from mineral oil.<br>However, since Citro\u00ebn has also switched to glycol, MTBs are the only ones using brake oil in the modern era.<\/p>\n\n\n\n<h3 class=\"wp-block-heading u-mb-ctrl u-mb-10 has-medium-font-size\">Points to consider when choosing brake parts!<\/h3>\n\n\n\n<p class=\"u-mb-ctrl u-mb-10 has-small-font-size wp-block-paragraph\">Because brake fluid is not oil, brake parts do not require oil resistance.<br>What is required is chemical resistance (brake fluid resistance).<br>You might think, &#8220;Be careful when buying brake parts!&#8221;\u2026 but reservoir tanks and hoses sold by parts manufacturers are naturally made of materials that are resistant to brake fluid.<br>So there is no need to worry.<br>The danger is mistakenly buying an oil-resistant one at a home improvement center just because it is &#8220;cheap.&#8221;<\/p>\n\n\n\n<p class=\"has-small-font-size wp-block-paragraph\">Brakes are &#8220;critical safety parts.&#8221;<br>Let&#8217;s buy reliable parts from trusted stores.<\/p>\n","protected":false},"author":1,"featured_media":16562,"template":"","class_list":["post-16561","tips","type-tips","status-publish","has-post-thumbnail","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/tsrjp.com\/en\/wp-json\/wp\/v2\/tips\/16561","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tsrjp.com\/en\/wp-json\/wp\/v2\/tips"}],"about":[{"href":"https:\/\/tsrjp.com\/en\/wp-json\/wp\/v2\/types\/tips"}],"author":[{"embeddable":true,"href":"https:\/\/tsrjp.com\/en\/wp-json\/wp\/v2\/users\/1"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/tsrjp.com\/en\/wp-json\/wp\/v2\/media\/16562"}],"wp:attachment":[{"href":"https:\/\/tsrjp.com\/en\/wp-json\/wp\/v2\/media?parent=16561"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}