12558968 - 8.1l Waterpump Bypass Hose

12558968 - 8.1l Waterpump Bypass Hose


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Part# 12558968


  • Brand New Workhorse Waterpump (thermostat) Bypass Hose for 8.1L Engines in Workhorse Chassis.


  • All Workhorse Chassis Equipt with an 8.1L Engine


What is the part number of the coolant crossover for the 8.1L 2004 p32 ( John, 02/15/2018 )
The part number for the crossover pipe was 12560724. Unfortunately that part is no longer available. ( Support )

Is the 8.1l water pump Bypass Hose used to bypass the heater? In other words does the hose eliminate the hose going to and coming from the heater core? Thanks for you help. Dave

( dave, 05/15/2015 )


No, that is not what the waterpump bypass hose is for. Here is a description of it's purpose that I found on Hot Rod Magazines website:

All engines that run a thermostat need to have some type of bypass provision to avoid localized hot spots, minimize the chance of steam pockets developing, promote even and rapid warm-up, and prevent water-pump cavitation. On some engines, such as classic Chevy small-blocks, the bypass is internal; on others, such as your big-block Chevy, the bypass is external.


( Support )

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WARNING: Products may contain one or more chemicals known in the State of California to cause cancer and/or birth defects or other reproductive harm. For more information, visit www.P65Warnings.ca.gov

VIN Verification Service Item

This product allows for a VIN verification service.

  • This is a service that we provide free of charge when a part is purchased.
  • When you provide your VIN below we will personally verify your part selection by your VIN before shipment of your order.
  • This helps ensure that this is the correct part for your vehicle.
  • This is not an automatic VIN check, it is done by a parts specialist once order is placed.
  • We can only VIN verify vehicles back to model year 1996, if older we can help but can't guarantee fitment.
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NOTICE: For orders outside of United States

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  • Views: 70665
  • Brand: Workhorse
  • Product Code: 12558968
  • Availability: 10
  • $49.79
  • $36.88

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