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Dodge Dart Engine Coolant Bypass Hose Guide for 1971-1977 Models

Everything you need to know about replacing the coolant bypass hose on your classic Dodge Dart.

3 minutes to read 1971-1977 Dodge Dart
Difficulty
1/5
Est. Time
0.5 hrs
DIY Doable?
✅ Yes
Shop Labor
$75-$150
🚫 Do not drive — Driving with a known coolant leak is not recommended, as a sudden hose failure could cause catastrophic engine damage from overheating.
Key Takeaways
  • The bypass hose is essential for proper engine warm-up and preventing hot spots in your Dart's engine.
  • Symptoms of failure include leaks, coolant smell, and potential engine overheating.
  • Aftermarket brands like Dayco and Gates are the primary replacement options; both are considered reliable choices.
  • This is a simple, low-cost repair that is highly recommended for DIY replacement to prevent future engine damage.
The engine coolant bypass hose on your 1971-1977 Dodge Dart plays a small but vital role. It allows coolant to circulate inside the engine block before the thermostat opens. This process helps the engine warm up evenly and prevents damaging hot spots from forming in the cylinder heads. It also relieves pressure on the water pump when the thermostat is closed. Without a functioning bypass hose, your Dart's engine may warm up too slowly or develop serious issues from uneven heating.

Is Your Dodge Dart's Bypass Hose Failing?

The coolant bypass hose is a small, U-shaped rubber hose, usually connecting the water pump to the intake manifold. Over decades of use, the rubber breaks down from heat and exposure to coolant. A failure here can lead to serious engine problems, so it's important to recognize the warning signs.

Symptoms of a Bad Bypass Hose

  • Coolant Leaks: You might see puddles of green or orange fluid under your car. Small leaks can be harder to spot and may appear as white or pink crusty residue on the engine near the hose.
  • Coolant Smell: A sweet, syrupy smell from the engine bay is a classic sign of a coolant leak.
  • Low Coolant Level: If you have to add coolant to the radiator or overflow tank often, you likely have a leak somewhere in the system.
  • Engine Overheating: A significant leak from the bypass hose will cause the engine to lose coolant and overheat, which can lead to severe engine damage.
  • Visible Hose Damage: Check the hose for cracks, swelling, or a spongy, soft feel. Any of these signs mean it's time for a replacement.

Critical Part for Engine Health

Do not ignore symptoms of a failing bypass hose. A sudden burst can cause a rapid loss of coolant, leading to engine overheating and potentially a cracked cylinder head or other major damage.

Choosing the Right Aftermarket Bypass Hose

For a classic vehicle like the 1971-1977 Dodge Dart, finding an original OEM Mopar hose is nearly impossible. Aftermarket parts are the go-to choice. The two most common brands you will find are Dayco and Gates.

  • Dayco: Often considered a reliable brand. Some mechanics find their hoses to be slightly thicker than competitors.
  • Gates: A major player in the aftermarket world, known for good quality and having accurate parts catalogs. Some users feel their quality is superior to Dayco.

Pro Tip: Both Dayco and Gates are reputable brands that will serve a classic Dart well. Forum discussions show that mechanics have differing preferences, but neither brand is considered low-quality. The most important factor is ensuring the hose is a direct fit for your specific engine (Slant-6 or V8) and is not a universal or flex hose.

Cost of a New Engine Coolant Bypass Hose (1971-1977 Dodge Dart)

Part Type Estimated Cost
New Aftermarket (Dayco, Gates) $20.08 - $81.22
Shop Labor $75 - $150

Frequently Asked Questions

Can I replace the bypass hose myself?

Yes, this is a very DIY-friendly job for most home mechanics. The hose is usually easy to access in the engine bay of a classic Dart. It is held on by two simple hose clamps. The job typically takes less than an hour.

Should I replace the hose clamps too?

Yes. It is highly recommended to replace the old hose clamps whenever you install a new hose. This ensures a tight, leak-free seal. Spring-style clamps are often preferred as they maintain constant tension as the hose expands and contracts with temperature changes.

Are there any recalls for the Dodge Dart coolant bypass hose?

No, there are no active recalls or Technical Service Bulletins (TSBs) from the NHTSA for the engine coolant bypass hose on 1971-1977 Dodge Dart models.

What kind of coolant should I use?

For this era of vehicle, a conventional green or yellow ethylene glycol-based coolant is typically recommended. Always mix it with distilled water according to the instructions on the bottle, usually a 50/50 ratio.

Technical Specifications

OEM Part Numbers: 22776

Molded EPDM rubber hose designed to resist heat, ozone, and chemical degradation from coolant. Specific shape varies between Slant-6 and V8 engines.

Wrenchy
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Meet Wrenchy → Updated Mar 31, 2026

The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.

Year Coverage
This article covers the Engine Coolant Bypass Hose for:
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