Go-Parts
Cart 0
Your cart is empty
Add an item to see it appear here.
Wrenchy
Go-Parts Garage
Expert guides for diagnosing, troubleshooting, and replacing auto parts Expert guides for diagnosing and replacing auto parts
Browse All →

Engine Coolant Bypass Hose Replacement for the 1967-1971 Chrysler New Yorker

This small, often overlooked hose is critical for preventing damaging hot spots in your New Yorker's big-block engine.

4 minutes to read 1967-1971 Chrysler New Yorker
Difficulty
3/5
Est. Time
2.5 hrs
DIY Doable?
✅ Yes
Shop Labor
$150-$300
🚫 Do not drive — If the hose is actively leaking or has burst, do not drive the vehicle, as rapid coolant loss will lead to severe engine damage from overheating.
Key Takeaways
  • The bypass hose is essential for proper engine warm-up and preventing damaging hot spots in your Chrysler's V8 engine.
  • Failure symptoms include coolant leaks, overheating, and a sweet antifreeze smell.
  • High-quality aftermarket hoses from brands like Gates or Dayco are the recommended and most reliable replacement option.
  • Replacement can be challenging for DIYers as the alternator and other accessories often need to be removed for access.
The engine coolant bypass hose on a 1967-1971 Chrysler New Yorker is a small but vital part of the cooling system. It allows coolant to circulate within the engine even when the thermostat is closed. This is especially important during warm-up, as it prevents steam pockets and damaging hot spots from forming in the cylinder heads of the large V8 engine. By allowing a small amount of coolant to bypass the closed thermostat and flow from the intake manifold back to the water pump, it ensures the engine heats up evenly and also relieves pressure on the water pump.

Symptoms of a Failing Coolant Bypass Hose

A bad bypass hose will usually make itself known. Because it is constantly exposed to hot coolant and engine vibration, the rubber will eventually break down. Keep an eye out for these signs:

  • Coolant Leaks: This is the most common symptom. You may notice a puddle of green or yellow coolant under the front of the engine. The leak might be a slow drip from the hose connections or a more serious spray from a crack in the hose body.
  • Sweet Smell: You might smell the distinct, sweet odor of antifreeze from the engine bay before you even see a leak. This indicates coolant is escaping and burning off on the hot engine.
  • Engine Overheating: A small leak can eventually lead to low coolant levels and overheating. A sudden burst of the hose will cause a rapid loss of coolant and can make the engine overheat very quickly, which can cause serious damage like a blown head gasket.
  • Visible Hose Damage: When the engine is cool, inspect the hose. A failing hose may feel overly soft and spongy, or hard and brittle. Look for visible cracks, splits, or swelling, especially near the clamps.

Critical Component Warning

Do not ignore symptoms of a failing bypass hose. A sudden burst can lead to rapid coolant loss and catastrophic engine damage from overheating.

Choosing the Right Aftermarket Hose

For a classic vehicle like the 1967-1971 New Yorker, finding a New Old Stock (NOS) Mopar bypass hose is nearly impossible and would be very expensive. A used hose is not a safe option, as rubber degrades over time regardless of use. The best and most reliable choice is a new aftermarket hose from a quality brand.

  • Tier 1: Reputable Aftermarket Brands (Recommended)
    Brands like Gates and Dayco are the industry standard for replacement hoses. They manufacture molded hoses that are designed to be a direct fit. These hoses are made from modern EPDM rubber, which is engineered to resist heat, ozone, and electrochemical degradation—the leading cause of hose failure.
  • Tier 2: Store Brands & Value Lines
    While often functional, the quality control and material compounds of lesser-known brands may not match those of top-tier suppliers. For a critical component that is difficult to access, spending a few extra dollars for a premium brand like Gates or Dayco is a worthwhile investment in reliability.

Pro Tip: Replace the Clamps

Always replace the hose clamps when you replace the hose. Old clamps can lose their tension or corrode, leading to leaks even with a new hose. Simple worm-gear clamps are effective and inexpensive.

Estimated Replacement Costs

Part Estimated Cost
New Aftermarket Hose (Gates, Dayco) $10 - $25
Shop Labor $150 - $300
Total Estimated Cost (At a Shop) $160 - $325

Note: Labor costs can vary significantly based on shop rates and whether other components need to be removed for access. On many Chrysler big-block engines, the alternator and/or A/C compressor bracket must be removed to reach the bypass hose.

Frequently Asked Questions (FAQ)

Can I use a generic straight hose instead of a molded one?

It is not recommended. The bypass hose on these engines often has a specific shape or bend to clear other components. Using a straight hose can cause it to kink, which restricts coolant flow, or rub against other parts, leading to premature failure.

How difficult is it to replace the bypass hose myself?

The job is feasible for a DIY mechanic, but can be challenging due to tight access. You will need to drain the cooling system and likely remove the alternator, its bracket, and possibly the A/C compressor to get clear access to the hose clamps. If you are not comfortable removing these accessories, it is best to leave the job to a professional.

Are there any recalls for the coolant bypass hose on my New Yorker?

No, there are no active recalls or Technical Service Bulletins (TSBs) from Chrysler or the NHTSA specifically for the engine coolant bypass hose on the 1967-1971 Chrysler New Yorker.

How often should coolant hoses be replaced?

As a general rule for classic cars, it's wise to inspect all coolant hoses annually. Many experts recommend replacing all rubber coolant hoses every 5-7 years as preventative maintenance, regardless of their appearance, to avoid being stranded by a sudden failure.

Technical Specifications

Typically a short, molded EPDM rubber hose connecting the water pump housing to the intake manifold. Common aftermarket part numbers include Gates 21633 or Dayco E71413, but always verify fitment for your specific engine and year.

Wrenchy
Article researched & written by
Go-Parts' AI research assistant. Every article is backed by live web research, verified OEM data, and real technician knowledge — so you get accurate, up-to-date information you can trust.
Meet Wrenchy → Updated Jul 21, 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:
In this article
Symptoms of a Failing Coolant Bypass Hose
Jump to ▴

Email This Guide

We'll send you a link to this article so you can read it later or share it.

Added to cart · Part