{"id":4384,"date":"2026-10-26T05:53:44","date_gmt":"2026-10-26T05:53:44","guid":{"rendered":"https:\/\/www.hongtengdaparts.com\/product\/caterpillar-170-9918-fan-pump-385c-390d\/"},"modified":"2026-10-26T05:53:44","modified_gmt":"2026-10-26T05:53:44","slug":"%e5%8d%a1%e7%89%b9%e5%bd%bc%e5%8b%92-170-9918-%e9%a3%8e%e6%89%87%e6%b3%b5-385c-390d","status":"publish","type":"product","link":"https:\/\/www.hongtengdaparts.com\/th\/product\/caterpillar-170-9918-fan-pump-385c-390d\/","title":{"rendered":"170-9918 \u6db2\u538b\u98ce\u6247\u6cf5\uff0c\u9002\u7528\u4e8eCAT 385C 390D\u6316\u6398\u673a\uff0c\u67f1\u585e\u6cf5"},"content":{"rendered":"<p>On the big C-series machines the fan pump is a piston unit rather than a gear pump, which means it can vary its output and can also fail in more ways. This page is deliberately narrow about fitment, because 170-9918 is one of the numbers the trade applies loosely across several tonnage classes.<\/p>\n<h2>What Caterpillar calls it<\/h2>\n<p>170-9918 is listed as a hydraulic piston pump, with the parts book item name PUMP GP-PISTON. That distinguishes it from the gear-type fan pumps used on the smaller C-series machines such as the 325C, where the supply unit is a ten-tooth gear pump. On a 385C or 390D the fan pump is doing variable output work, and its control is where faults start.<\/p>\n<h2>Fitment, stated honestly<\/h2>\n<p>Trade parts data and supplier cross-references attach 170-9918 to CAT 374 and 374D, 385C, 390C and 390D, and to the 5090B, running C18 and 3456 engines.<\/p>\n<p>What we cannot confirm: listings that put this pump on a 365C or a 385B. The 365C fan pump in Caterpillar&#8217;s own numbering is 247-8968, cross-referenced as 10R-6278, and we list it on its own page. If you have been quoted 170-9918 for a 365C, check the number on the old unit before you accept it. We would rather lose the order than ship a pump that will not bolt up.<\/p>\n<h2>The circuit this pump serves<\/h2>\n<p>A 385C or 390D in the 80 to 90 tonne band rejects a large amount of heat through its cooling package, and the fan is hydraulically driven with speed controlled from coolant and hydraulic oil temperature. The pump&#8217;s displacement is varied in response to that demand. Three failure modes follow from that arrangement:<\/p>\n<ul>\n<li><strong>Loss of displacement.<\/strong> Internal wear means the pump cannot deliver the flow the fan needs at full command. Fan speed is capped, oil temperature climbs, and the machine derates.<\/li>\n<li><strong>Control stuck at part stroke.<\/strong> A sticky spool or a failed solenoid holds output low even when the controller asks for full cooling. This is the fault most often misdiagnosed as a bad fan motor.<\/li>\n<li><strong>Cavitation from the supply side.<\/strong> A restricted suction line or a low oil level makes the pump noise and slowly destroys it. If the old pump was noisy before it failed, check the suction path before blaming the unit.<\/li>\n<\/ul>\n<p>Test in that order. Our <a href=\"https:\/\/www.hongtengdaparts.com\/th\/%e6%8c%96%e6%8e%98%e6%9c%ba%e6%b6%b2%e5%8e%8b%e9%a3%8e%e6%89%87%e6%b3%b5%e8%af%8a%e6%96%ad\/\">\u6db2\u538b\u98ce\u6247\u6cf5\u8bca\u65ad\u6307\u5357<\/a> covers flow and delivery pressure measurement, and <a href=\"https:\/\/www.hongtengdaparts.com\/th\/%e6%8c%96%e6%8e%98%e6%9c%ba%e4%b8%bb%e6%b3%b5%e8%b0%83%e8%8a%82%e5%99%a8%e8%af%8a%e6%96%ad%e8%b0%83%e6%95%b4\/\">the regulator article<\/a> covers the control signal. The mating motors in this class are 225-4613 for the 365C and 247-8978 for the 385C and 390D, and they are not interchangeable.<\/p>\n<h2>Fitting notes<\/h2>\n<p>Compare shaft, pilot, bolt pattern and port orientation against the removed unit before cleanup begins. Prime the casing with clean oil before cranking. Fit a new return filter element and clear the suction strainer. Route the case drain directly to tank with no restriction, since back-pressure in the casing is what finishes shaft seals. Confirm the control connector is seated, then prove full fan speed under thermal load and log both temperatures.<\/p>\n<p>Cleanliness target for axial piston units in mobile service is around ISO 4406 18\/16\/13 on Bosch Rexroth guidance. If the machine has already lost a pump, inspect the drive train before fitting: <a href=\"https:\/\/www.hongtengdaparts.com\/th\/%e6%8c%96%e6%8e%98%e6%9c%ba%e6%b6%b2%e5%8e%8b%e6%b3%b5%e9%a9%b1%e5%8a%a8%e9%bd%bf%e8%bd%ae%e6%a3%80%e6%9f%a5\/\">\u9a71\u52a8\u9f7f\u8f6e\u68c0\u67e5<\/a> \u4ee5\u53ca <a href=\"https:\/\/www.hongtengdaparts.com\/th\/%e6%8c%96%e6%8e%98%e6%9c%ba%e6%b3%b5%e5%88%86%e5%8a%a8%e7%ae%b1%e6%95%85%e9%9a%9c%e8%af%8a%e6%96%ad\/\">transfer case failure diagnosis<\/a> cover what to look for.<\/p>\n<h2>\u6761\u6b3e<\/h2>\n<p>Minimum order one piece. New aftermarket units carry a three to six month warranty as stated on your proforma invoice. Bench tested, photographed against your order before the wooden case closes, delivery 5 to 8 working days from payment subject to stock, by sea, air or express courier. Related pages: <a href=\"https:\/\/www.hongtengdaparts.com\/th\/product\/caterpillar-247-8968-fan-pump-365c-374d\/\">247-8968 fan pump<\/a> \u4ee5\u53ca <a href=\"https:\/\/www.hongtengdaparts.com\/th\/product\/caterpillar-225-4613-fan-motor-365c\/\">225-4613 fan motor<\/a>. The full range sits under <a href=\"https:\/\/www.hongtengdaparts.com\/th\/product-category\/%e0%b8%a1%e0%b8%ad%e0%b9%80%e0%b8%95%e0%b8%ad%e0%b8%a3%e0%b9%8c%e0%b8%9e%e0%b8%b1%e0%b8%94%e0%b8%a5%e0%b8%a1%e0%b9%84%e0%b8%ae%e0%b8%94%e0%b8%a3%e0%b8%ad%e0%b8%a5%e0%b8%b4%e0%b8%81\/caterpillar-fan-motor\/\">Caterpillar\u6db2\u538b\u98ce\u6247\u9a6c\u8fbe<\/a>.<\/p>","protected":false},"excerpt":{"rendered":"<p><strong>\u96f6\u4ef6\uff1a<\/strong> 170-9918\u6db2\u538b\u98ce\u6247\u6cf5\uff0cCaterpillar\u5c06\u5176\u5217\u4e3a\u6db2\u538b\u67f1\u585e\u6cf5\uff0c\u96f6\u4ef6\u6587\u732e\u4e2d\u5217\u4e3aPUMP GP-PISTON\uff08\u67f1\u585e\u6cf5\u603b\u6210\uff09\u3002.<\/p>\n<p><strong>\u9002\u7528\u673a\u578b\uff1a<\/strong> \u6839\u636e\u8d38\u6613\u96f6\u4ef6\u6570\u636e\uff0c\u4f9b\u5e94\u9002\u7528\u4e8e\u914d\u5907C18\u548c3456\u53d1\u52a8\u673a\u7684374\u3001385C\u3001390C\u548c390D\u673a\u5668\u3002.<\/p>\n<p><strong>\u4f9b\u8d27\u65b9\u5f0f\uff1a<\/strong> HTD\u54c1\u724c\u5168\u65b0\u66ff\u6362\u4ef6\uff0c\u4e2d\u56fd\u5236\u9020\u3002\u6700\u5c0f\u8d77\u8ba2\u91cf1\u4ef6\uff0c\u6728\u7bb1\u5305\u88c5\uff0c5\u81f38\u4e2a\u5de5\u4f5c\u65e5\u5185\u53d1\u8d27\u3002.<\/p>","protected":false},"featured_media":4363,"template":"","meta":[],"product_brand":[],"product_cat":[599,37],"product_tag":[628,629,630,54,555],"class_list":["post-4384","product","type-product","status-publish","has-post-thumbnail","product_cat-caterpillar-fan-motor","product_cat-hydraulic-fan-motor","product_tag-170-9918","product_tag-cat-385c","product_tag-cat-390d","product_tag-caterpillar","product_tag-fan-pump","first","instock","shipping-taxable","product-type-simple"],"_links":{"self":[{"href":"https:\/\/www.hongtengdaparts.com\/th\/wp-json\/wp\/v2\/product\/4384","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hongtengdaparts.com\/th\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/www.hongtengdaparts.com\/th\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.hongtengdaparts.com\/th\/wp-json\/wp\/v2\/media\/4363"}],"wp:attachment":[{"href":"https:\/\/www.hongtengdaparts.com\/th\/wp-json\/wp\/v2\/media?parent=4384"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/www.hongtengdaparts.com\/th\/wp-json\/wp\/v2\/product_brand?post=4384"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.hongtengdaparts.com\/th\/wp-json\/wp\/v2\/product_cat?post=4384"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.hongtengdaparts.com\/th\/wp-json\/wp\/v2\/product_tag?post=4384"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}