How to Find Discontinued Generac 75D Coolant Hose C4845 for 2003 Newmar Dutch Star RV

What's Going On

Your Generac 75D coolant hose part #C4845 is indeed discontinued, which is frustrating when you're so close to completing your cooling system overhaul on your 2003 Dutch Star. The good news is that you have several viable options to track down this specific hose or find a suitable replacement. Since you've already sourced three of the four hoses, you're dealing with what's likely a uniquely shaped or sized hose that Generac used specifically for the 75D model's cooling circuit configuration.

For finding NLA (No Longer Available) parts like your C4845 hose, your best bets are specialized generator parts dealers, RV salvage yards that focus on motorhomes from the early 2000s, and aftermarket suppliers who manufacture replacement cooling system components. The hose itself is likely a molded rubber coolant line with specific bends and connection points that made it unique to your generator model.

Why This Happens

Generac discontinued many parts for older generator models like your 75D as they phase out support for units that are now 20+ years old. The C4845 hose was likely a low-volume part specific to your model's cooling system layout, making it economically unfeasible for Generac to continue manufacturing once warranty periods expired and demand dropped significantly.

The 2003 Dutch Star's Generac 75D was installed during a transition period when generator manufacturers were changing cooling system designs and hose routing configurations. This means your specific hose may not interchange with newer models, even if they appear similar. Additionally, the rubber compounds used in these hoses degrade over time, especially in the heat cycling environment of a generator compartment, which is why you're smart to replace all four hoses as a complete cooling system refresh.

Parts obsolescence is particularly challenging with RV-installed generators because they often used custom mounting brackets and hose routing that differed from the same generator model used in other applications. Your C4845 hose likely has specific bend angles and connection points that were designed around the Dutch Star's generator compartment layout.

Getting Ready

Before you start your search, take detailed measurements and photos of the existing C4845 hose from multiple angles. Measure the inside diameter of both ends, the overall length when laid flat, and note any special fittings or clamps. Document the routing path and any specific bend angles - this information will be crucial whether you're working with a parts supplier or a custom hose manufacturer.

Contact these specialized sources in order of likelihood: First, try Genuine Generac Parts dealers who might have old stock - call several locations as inventory varies. Next, contact RV salvage yards, particularly those in Arizona, California, and Florida where older motorhomes are more commonly found. Online forums like iRV2.com and specialized Generac generator groups on Facebook often have members parting out similar units.

For aftermarket options, research companies like Gates, Dayco, or Goodyear who manufacture cooling system hoses and might have a cross-reference or be able to manufacture a custom replacement. You'll also want to check with industrial hose suppliers in your area who can often fabricate custom coolant hoses using the proper high-temperature rubber compounds and reinforcement materials.

Gather your generator's serial number and any other identifying information from the data plate - sometimes parts suppliers can cross-reference based on the full unit specifications rather than just the model number. Having the complete cooling system schematic from your owner's manual will also help suppliers understand exactly what hose configuration you need.

Walking Through the Fix

Start your search by contacting these specific resources: Power Equipment Warehouse, Generac Parts Store online, and Norwall PowerSystems - they often maintain inventory of discontinued parts. Call rather than just checking websites, as many dealers have parts in their back rooms that aren't listed online. Provide them with your generator's serial number and the specific part number C4845.

If new old stock isn't available, measure your existing hose carefully and contact industrial hose suppliers like Parker Hannifin, Continental ContiTech, or local hydraulic hose shops. Many can fabricate a replacement using proper coolant-rated rubber with the correct temperature and pressure ratings. You'll need hose rated for generator cooling system specifications (check manufacturer requirements for exact temperature and pressure ratings) with ethylene glycol compatibility.

For the DIY approach, if you can't find an exact replacement, consider having a custom hose made using the original as a template. Remove the old hose carefully, lay it flat, and trace its shape onto cardboard to create a pattern. Take this pattern along with your measurements to a custom hose manufacturer - they can typically create a replacement for $40-80 depending on complexity.

Another option is to check if the hose can be replaced with multiple straight sections connected by appropriate elbows and couplers. Sometimes a complex molded hose can be replicated using standard straight hose sections and quality hose fittings, though this approach requires careful planning to ensure proper clearances in your generator compartment.

When you do find a replacement, inspect all your hose clamps and replace any that show signs of corrosion or wear. Use quality stainless steel clamps and tighten to proper torque specifications to ensure a leak-free seal.

Beyond DIY Territory

If you're unable to locate the C4845 hose through normal channels, consider contacting a mobile RV repair service that specializes in generators - they often have relationships with parts suppliers and salvage sources that aren't available to individual consumers. Many have successfully helped customers find discontinued parts through their professional networks.

For a more permanent solution, you might want to have an RV technician evaluate whether your cooling system could be modified to use currently available hoses. Sometimes the mounting points or routing can be slightly altered to accommodate a standard hose configuration, though this should only be done by someone experienced with generator cooling systems to ensure proper flow and heat dissipation.

Consider reaching out to Generac's customer service directly with your serial number and explain your situation - while they may not have the part, they sometimes can provide engineering drawings or specifications that would help a custom manufacturer create an exact replacement. They may also be able to suggest an authorized service center that has experience with discontinued parts for your model.

If all else fails, you might need to consider upgrading to a newer generator, especially if other components of your 20-year-old Generac 75D are showing signs of wear. The cost of tracking down multiple NLA parts and performing extensive repairs might approach the cost of a modern replacement unit that would provide better reliability and parts availability for years to come.