Mercedes W123 Radiator Hose Replacement

Member-Contributed Guide

Member-Contributed Guide

An awesome member of our community made this guide. It is not managed by iFixit staff.

Radiator hoses looking sad? Feeling stiff? Maybe even leaking? Keeping water inside your car is important for its health. Change them today.

The radiator hoses on your car are subject to a lot of abuse. Heat, expansion and contraction, corrosives, etc. attack them every time you drive and even when you're parked.The rubber hoses will eventually become brittle, and could begin leaking at their ends or may even crack and leak along their length.Be proactive and replace them today. All you need is a screwdriver!

Tools
Relevant Parts

Edit Step 1 Radiator Hose  ¶ 

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Edit Step 1 Radiator Hose  ¶ 

  • Begin by draining your radiator of coolant as [invalid guide link]. You will not need to drain the block for this process.

  • As always, never work on your coolant system when it is hot. This is very very dangerous.

Edit Step 2  ¶ 

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Edit Step 2  ¶ 

  • Find your upper coolant hose connection at the upper driver's side of the radiator.

  • Loosen the hose clamp on this end of the hose.

Edit Step 3  ¶ 

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Edit Step 3  ¶ 

  • Follow this hose to the top of the engine block, where it enters the thermostat housing.

  • Loosen the hose clamp on this end of the hose.

Edit Step 4  ¶ 

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Edit Step 4  ¶ 

  • Then use a hose clamp removal hook or other appropriate tools to work around under the edge of the hose. This will help break them free; they often stick to the necks they attach to over time.

  • Pull the hose off fully on both ends.

Edit Step 5  ¶ 

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Edit Step 5  ¶ 

  • Continue by loosening the clamp on the lower radiator hose where it connects to the thermostat housing.

Edit Step 6  ¶ 

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Edit Step 6  ¶ 

  • Then go underneath the car and loosen the clamp on the lower radiator hose where it connects to the radiator.

  • Remove the hose in the same manner you did the upper hose.

  • Now replace both hoses, and secure with hose clamps. Replace the hose clamps with new ones if they were difficult to open due to corrosion or stripped screw heads.

  • Finish by filling the system with coolant and bleeding the system as [invalid guide link]

To reassemble your device, follow these instructions in reverse order.

For more information, check out the Mercedes W123 device page.

Required Tools

Phillips #1 Screwdriver

$5.95 · 50+ In stock

Recommended Tools

54 Bit Driver Kit

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Pro Magnetic Project Mat

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Pro Tech Screwdriver Set

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Anti-Static Project Tray

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