{"id":53767,"date":"2017-11-01T09:41:47","date_gmt":"2017-11-01T14:41:47","guid":{"rendered":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/?p=53767"},"modified":"2026-02-12T08:30:38","modified_gmt":"2026-02-12T16:30:38","slug":"1999-chevy-12-ton-silverado-4by4","status":"publish","type":"post","link":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/2017\/11\/1999-chevy-12-ton-silverado-4by4","title":{"rendered":"1999 Chevy 1\/2 ton Silverado 4by4"},"content":{"rendered":"<p><img decoding=\"async\" class=\"alignnone size-full wp-image-36637\" src=\"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-content\/uploads\/2016\/09\/1999-chevy-z71.jpg\" alt=\"1999 Chevy Z71\" width=\"600\" height=\"229\" srcset=\"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-content\/uploads\/2016\/09\/1999-chevy-z71.jpg 600w, https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-content\/uploads\/2016\/09\/1999-chevy-z71-300x115.jpg 300w\" sizes=\"(max-width: 600px) 100vw, 600px\" \/><\/p>\n<p>What is the purpose of vacuum line attached to the rear end?<\/p>\n<hr \/>\n<h3>Differential Vent Tube<\/h3>\n<p>The vacuum line is a vent tube. This keeps the unit from building pressure internally. It also moves the point of entry above any perceived area of water exposure. For example, Suppose you were to back a boat into the water. The vent tube is positioned high enough not to allow water to enter into the differential that may now be under water.<\/p>\n<p><img decoding=\"async\" class=\"alignnone size-full wp-image-53897\" src=\"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-content\/uploads\/2017\/10\/1999-chevy-differential-tube-diagram.gif\" alt=\"differential vent tube diagram\" width=\"320\" height=\"296\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>What is the purpose of vacuum line attached to the rear end? Differential Vent Tube The vacuum line is a vent tube. This keeps the unit from building pressure internally. It also moves the point of entry above any perceived area of water exposure. For example, Suppose you were to back a boat into the&hellip;&nbsp;<a href=\"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/2017\/11\/1999-chevy-12-ton-silverado-4by4\" rel=\"bookmark\">Read More &raquo;<span class=\"screen-reader-text\">1999 Chevy 1\/2 ton Silverado 4by4<\/span><\/a><\/p>\n","protected":false},"author":14216,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"","neve_meta_content_width":0,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","footnotes":""},"categories":[1,3],"tags":[20469,393,20467,20468],"class_list":["post-53767","post","type-post","status-publish","format-standard","hentry","category-auto-repair-questions","category-chevy","tag-differential-tube","tag-silverado","tag-vacuum-line","tag-vent-tube"],"_links":{"self":[{"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/posts\/53767","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/users\/14216"}],"replies":[{"embeddable":true,"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/comments?post=53767"}],"version-history":[{"count":1,"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/posts\/53767\/revisions"}],"predecessor-version":[{"id":83599,"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/posts\/53767\/revisions\/83599"}],"wp:attachment":[{"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/media?parent=53767"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/categories?post=53767"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/tags?post=53767"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}