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Don’t Forget The Cooling System!

To ensure all damage is diagnosed in a front-end collision, technicians need to conduct a thorough inspection of the cooling system.


Early film versions of the Titanic saga depicted
the mayhem that resulted from the mistakes made during the vessel’s
maiden voyage. For its time, Titanic was well-designed. And though
the latest romantic depiction of the ship’s fate might lead you
to believe otherwise, many experts contend that the damage could
have been managed had the true extent of the problem been realized

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Too often, today’s collision repair shops
work off a similar assumption – that a bird’s-eye view of mechanical
and other related systems is all that’s required to solve the
problem and get the vehicle out the door. One area that frequently
suffers from this assumption is the automotive cooling system.

Cooling-System Concerns

The single biggest concern techs have when
repairing a head-on or front-impact collision is re-establishing
control points and establishing correct datum lines. Often, a
core support is repaired when it should be replaced because it
will be well-hidden behind grillwork, the condenser and other
assorted hardware. The problem with this is that the radiator,
as well as other sensitive components, may be placed under tension
and eventually develop leakage. (Radiator core and other post-collision-related
leaks can be the No. 1 killer of multi-valve aluminum-construction

The Automotive Service Association (ASA) says
that even small leaks can result in continually low systems that
transfer steam to critical areas, creating super hot spots as
well as gasket and casting failure. Ever noticed all of the air
bleeds currently found on modern cooling systems? This should
tell you that air – even a little air – is taboo in these systems.


Pressure testing for leaks should take place
prior to draining a system for repairs and after radiator or other
system replacement. If possible, a flush/recycle machine can be
used to remove deposits in the system; it can also do a better
job bleeding the cooling system than if you simply used the factory
bleed screws. Even if you’re not inclined to get involved in cooling-system
recycling services, these reverse-flush machines with pumps are
great for ordinary service.

Cooling-System Check Points

How can you be sure your technicians are conducting
a thorough examination of a vehicle’s cooling system? The following
component check points should prove helpful:

  • Radiators – Three- and four-row radiators used to be
    few and far between in basic passenger cars, but not anymore.
    Hotter-running engines with bigger transmission packages – as
    well as other complications created by higher-pressure, hotter
    condensers used with H.F.C. 134 – have changed all of that. Today’s
    new air conditioners depend on the efficiency level of the radiator
    to aid in the convection process when heat is given up at the
    condenser. Any radiator problems will make an air conditioner’s
    life a very short one if not taken care of directly. Shops should
    also check for restrictions from post-collision debris or foreign
    material, such as masking paper and the like, that might cause
    problems after the repaired vehicle has been released.
  • Thermostats – It never hurts to replace the thermostat
    with the factory-recommended design when you’ve opened the system
    for major cooling-system repairs. The reason might be time or
    mileage. Also, don’t forget that hard calcium-like deposits knocked
    loose during the collision could have made their way into the
    water jacket and thermostat housing, causing the unit to stick
    shut or open. Take note of how the thermostat is mounted. Some
    Ford designs, for example, require that the thermostat be sort
    of cork screwed in place. A mistake here can cause plenty of future
    cooling-system problems.
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  • Plastic tanks – Plastic tanks on radiators and other
    more creative core designs of similar nature can be less of a
    problem if you remove the items and do a submerged core test using
    air pressure. A leap of faith here – rather than a sure test –
    might make you very sorry later. I know of one shop owner who
    suggests the customer pay the difference between the component
    the insurance company pays to replace and a heavy-duty upgrade,
    such as those found in the aftermarket. The difference in cooling
    capacity alone makes it beneficial, he says. Add to this the future
    reparability of the heavier unit, and it’s a win/win situation
    for all involved.
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  • Fans – Electric cooling fans are more survivable than
    initially thought to be. The motors will usually hold up even
    if they were engaged at the time the impact took place. Being
    careful when replacing fan-blade assemblies and mounts can eliminate
    vibration and noise, as well as add to cooling-system efficiency

    Cooling fans that are computer controlled through relay banks
    or operated directly via sensors are generally very survivable,
    say most collision shop owners. Scan tools are a big help in finding
    problem areas. Often, a computer sensor or the vehicle control
    module (VCM) is found to be the problem when a fan system doesn’t
    work properly.

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    • Belts – Timing belts are good as gold in most vehicles
      until around 70,000 miles. Cooling systems that fail after a collision
      repair because a timing belt was replaced but a worn or damaged
      water pump was neglected seem to be frequent problems for shops.
      Insurance companies may not want the extra expense, but who’ll
      be left bobbing around in open water when the pump fails a week
      later when your customer is driving on the freeway? Keeping the
      customer involved in the repair is your best bet here. Be sure
      to suggest any repairs that will keep you out of trouble.

    And don’t forget to follow routing directions for reinstalling
    accessory drive belts and pulleys. We’ve all seen water pumps
    and mechanical fans turning backward. These kinds of mistakes
    are easily prevented by strictly adhering to parts-manuals data
    or by heeding any applicable footnotes.

    • Airflow – Today’s automobile is designed for a low
      drag coefficient in a wind tunnel, so fairings, air dams and duct
      work all must be in place and in proper working order to deflect
      cool air toward the radiator and engine compartment to exchange
      heat. However, this doesn’t mean we can ignore the need to route
      air efficiently and cool the power plant. During inspection for
      body or chassis damage, pay close attention to these items so
      they can be repaired or replaced correctly to allow for correct
      cooling-system operation.

    The Right Tools

    Failing to locate a clogged radiator, a bad water pump or a restricted
    cooling passage won’t make you any more popular than White Star
    Lines was just after the sinking of the Titanic. Finding the problems
    mentioned earlier will help build a solid reputation for your
    shop and put some bucks in your bank account. And with the right
    tools, identifying cooling-system problems should be easy.


    Toys of all kinds are out there to help you find cooling-system
    problems invisible to the naked eye. I came across a neat flow
    device that can determine the total rate of flow in the cooling
    system. Other neat gadgets that have improved with time are ultraviolet
    (UV) leak-detector systems that use dye in the cooling system
    to pinpoint small leaks that otherwise might be overlooked.

    Prices on this equipment have come down considerably, and any
    collision shop could use one for basic inspection, as well as
    for the final check before the last road test.


    Smooth Sailing

    Conducting a thorough inspection of a vehicle’s cooling system
    and related parts is an important part of the total repair process.
    However, it often gets neglected because many of the necessary
    repairs are hidden from the naked eye. "Out of sight, out
    of mind," they often say. Unfortunately, the vehicle won’t
    be out of sight for long when the customer brings the vehicle
    back to your shop complaining of cooling-system problems you could
    have – and should have – fixed when the car was in for repairs
    the first time.


    Contributing editor Bob Leone, a retired shop owner, is ASE
    Three-Way Master Certified and is completing qualifications as
    a post-secondary automotive instructor in the vocational school
    system in Missouri.

    The Scoop on Antifreeze

    Vehicle maintenance schedules recommend cooling-system services
    by mileage. Some new vehicles are equipped with organic, designated-100,000-mile-plus
    coolant that will either have to be restored by your shop after
    a repair is completed or converted to something else.

    The rules here are simple:

    If the system has been filled with another type of coolant, namely
    an ethylene or propylene coolant, restore the vehicle to one or
    the other of these formulas with a thorough flushing. Check for
    leaks, refill the system with the desired coolant and then designate
    on the work order the coolant formula and brand used, as well
    as the freeze-protection temperature reading. (Remember that ethylene
    and propylene take separate hydrometers to obtain a correct readout
    for coolant/boil protection.) Refractometer testing will be your
    best bet when dealing with any of the three specific formulas
    of coolant, as well as many of the private and alternate brand
    labels, to check freeze protection accurately.


    If you’re working on a system filled with the new organic coolant,
    things are a lot different. The ability to obtain the remarkable
    extended life and the coolant protection depends on strict adherence
    to a "no contamination policy." As little as 5 percent
    foreign (other formula) coolant will drastically change the corrosion
    package in the new coolant design mix. Even a thorough system
    flushing may allow some undesired coolant to remain in a cooling
    system. Therefore, the only way to be sure the system is pure
    and only contains the organic long-life mix is to only refill
    and/or top off with the organic mix. It’s also important to stick
    to the same brand of coolant. Use caution here and find out what,
    if any, recourse might be available if the material used causes
    failures to head gaskets or other components.


    Other tips to remember when working with antifreeze include:

    • Mixing any antifreeze with water according to instructions
      goes a long way toward maximum corrosion protection without complications.
      Silicate "drop out" has been found in the past when
      pure or close to pure solutions were placed in aluminum engines
      with lightweight cooling-system components.

    • Shops that repair radiators on site will often find other
      chemical additives have settled in radiator core tubes and tanks,
      creating a looming restriction problem or worse. Advise customers
      to only use approved cooling-system treatments at correct dosage
      levels when the situation dictates. Also be sure to check for
      special instructions that may be specific to makes or models requiring
      the addition of a sealer into the cooling system to defray block
      or casting porosity problems.
  • As with any hazardous material your shop generates, dispose
    of all types of coolants in accordance with local, state and federal
    guidelines. Even the organic blend of coolant may pick up deposits
    that will categorize it as hazardous material.
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