DIY Network

Auto Primer Basic: Routine Hose Check How to check coolant hoses for wear and replace worn hoses From "Auto Primer" episode DAPR-103

Cooling system hoses, such as these radiator hoses, may be vehicle-specific. Leilani compares the old hose with the replacement to ensure that they are comparable.

Materials:

Standard automotive tools (socket-wrenches, screwdrivers, nut-drivers, etc.)
Replacement hoses: radiator hoses (upper and lower); 2 heater hoses
Hose clamps
Drain pan
Distilled water
Funnel
Bucket
Pliers
Safety glasses

Safety Alert: Always wear eye protection when working with power tools or hazardous chemicals.

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	Figure A
	Figure B
	Figure C

Routine Hose Inspection

Maintenance Tip -- Inspecting Hoses: It’s a good idea to have your cooling-system hoses inspected every three to four months or every three to four thousand miles or every time you change your oil.

A routine hose inspection is something that you can do yourself. It's a good idea to do this about every three or four months.

You'll need to inspect the radiator hoses (figure A) -- both upper and lower.

You'll also need to inspect the heater hoses (figure B). Some heater hoses are metal, but some are rubber or have rubber fittings or elbows. Don't forget to check the heater hoses coming you’re your engine-block, leading back to the firewall.

Finally, you'll need to check the overflow hoses (figure C) and the supply hose that leads into your reservoir tank.

One of the key things to look for is cracks in the hose (figure D). Squeeze the hoses. They should be firm, but flexible with no thin or hard spots. Large cracks or splits in the middle of the hose (figure E) are especially problematic. Also look for spots that may be bulging or discolored as this may be indicative of internal damage.

Abrasions from hoses rubbing up against a moving part or burn-through from heat are other common problems. If you find any areas that swollen, hard, cracked or leaking, replace the hoses right away.

Figure D

Figure E

Figure F

Replacing a Radiator Hose

Maintenance Tip -- Routine Hose Replacement : All hoses should be changed every four to five years or every 60,000 miles.

Replacing cooling-system hoses is not a terribly complicated procedure, and it's a job that novice do-it-yourself mechanics should be able to handle fairly easily. The basic steps are outlined below. For demonstration purposes, and to make it easier to see the parts, we conducted our replacement on a radiator mounted on a display rather than inside the vehicle. We began with a set of replacement hoses: upper and lower radiator hose, heater hoses, overflow hose and replacement hose-clamps (figure F).

Note: For this demonstration, we replaced the upper radiator hose. The procedure for replacing the other cooling-system hoses is roughly the same.

Important: Hoses are frequently vehicle-specific. Be certain to get the proper replacement hoses for your vehicle to ensure a proper fit.

Important Safety Precautions

Though work on your vehicle's cooling system is typically not a difficult automotive procedure, there are several safety issues that you must be of before you begin work. Here are some important safety precautions:
• Safety Alert: Radiators and engines get extremely hot, and opening a radiator before it has cooled is extremely dangerous. Before you begin work, be certain to let your engine cool fully.

• Safety Alert: Coolant, or antifreeze, is extremely toxic and harmful to the environment. Because it has a sweet smell but is highly poisonous, it is especially hazardous if young children or animals around. Always keep coolant away from children or pets. Wash your hands thoroughly after working with coolant to prevent contact with the eye.

• Safety Alert: As a standard safety precaution, disconnect your car's negative battery cable before you start any mechanical or electrical work on the vehicle. For this procedure, this is especially important if the car has an electric cooling fan.
  

  	Figure G
  	Figure H

• Begin the procedure by draining your radiator. First, loosen the radiator cap. Then locate the radiator drain-plug or petcock valve located near the bottom of the radiator (figure G).

• Loosen the petcock valve to allow the radiator to drain into a catch basin (figure H).

• Important:Always dispose of automotive fluids responsibly. Many auto centers have auto-fluid recycling centers. Contact your local municipality for information on proper disposal instructions.
  

  	Figure I
  	Figure J

  
  

• Begin by loosening the hose clamp with a screwdriver or nut-driver (figure I).
  
  
• To free a stuck hose, twist and pull, but don’t use too much pressure. Forcing could damage the fitting. If the old hose can't be pulled or twisted free of the fitting, you can always cut it off to remove it. (The old hose will be discarded anyway.)
  
  
• Loosen the clamp on the other end of the hose (figure J) using caution to avoid spilling any coolant that's left in the hose.
  

  Figure K

• Replace your old hose clamps with new ones and match the tightening screw direction with the ones you are replacing.
  
  
• Insert the proper end of the new hose over the fitting (figure K). Use caution not to damage the ridge at the end of the fitting since this is what facilitates a reliable seal.

  Auto Primer Tip: Smearing a little coolant on the inside of a new radiator hose, heater hose or overflow hose will allow the hose to slide onto the end of the fitting more easily.
  
  

• Slide a loosen clamp over the hose and push the hose into place past the ridge on the fitting until it is snug.
  
  
• Slide the clamp past the ridge on the fitting and tighten the clamp. Avoid over-tightening the clamp as this could damage the hose.
  
  
• After replacing all your hoses, double check the clamps to make sure they are tight.
  
  
• Refill with coolant.
  

  A hydrometer makes measuring coolant/water mix easy.

Auto Primer Quick-Tip: You can easily check for the proper ratio of water to antifreeze in your radiator using an antifreeze hydrometer, available at any auto center. Simply dip the tip of the hydrometer into the coolant mixture and use the squeeze bulb to draw some of the mixture up into the tool. An indicator, or floating indicator-balls, inside the tool will tell you if you have the correct mixture.

Note: This is a summary of steps and tips shown in this episode of Auto Primer. These are general guidelines and applicable to most contemporary vehicles. There may be variations in procedures depending on vehicle manufacturer, model, age or condition of vehicle and in the applicable parts, products or kit. Always follow proper safety precautions, and read and follow manufacturer's guidelines, diagrams and safety notices that come with any replacement parts or product that you select. Also, familiarize yourself with your owner's manual before doing any work on your vehicle.

RESOURCES :

The Complete Idiot's Guide to Trouble-Free Car Care
Author: Dan Ramsey
ISBN: 0028635833
Alpha Books

Auto Repair for Dummies
Author: Deanna Sclar
ISBN: 0764550896

How Cars Work
Author: Tom Newton
ISBN: 0966862309
Publisher: Black Apple Press
To order this title from Amazon, click here.

What's Wrong With My Car?: A Quick and Easy Guide to Most Common Symptoms of Car Trouble
Author: Bob Cerullo
ISBN: 0452269938
Publisher: Plume (1993)
To order this book from Amazon.com, click here.