Thread: Hurricane Leak
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Old 12-09-2019
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NoGas NoGas is offline
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Join Date: Apr 2012
Location: DFW & PHX
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Default M380 Hurricane Engine Pre-Heat Pump - Possible Design Flaw?

Have been trying to figure out why the Engine Pre-Heat pump housing which was replaced only 3-1/2 years ago cracked. Further investigation revealed a residual coating of glossy/hard white substance on the nipple threads on the engine preheat pump connection fitting which exits the H case. I will need to remove this substance before the threads will work with the newly repaired pump. Since the engine coolant water in this line continuously flows at 180°F or higher, could it be that either the threads of the plastic pump or something inside the pump melted and/or caused it to leak? The housing crack appears to go all the way through the pump housing at the connection point. However, based on the temperature characteristics of the materials used for the pump and impeller, I have also ordered a new impeller for my pump. Once fixed, should this issue crop up again I will follow Lance’s example but also internally bypass this pump (that I don’t use it anyway )

Notes: On checking the pump description, I discovered the pump body is made of Noryl Plastic and the impeller of Nylon. From the plastic manufacturer, Noryl has a Max Service Temperature of 163-189 °F and a Melting Temperature of 351-432 °F, while Nylon 6 typically exhibits a glass transition temperature of 48°C (118.4°F) and a melt temperature of 214°C (412°F).
Van & Toni in TX & AZ
2004 M380 DS & 2013 Fiat 500 Pop or 2021 Jeep JL
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