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
immediately.

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
engines.)

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.
• 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.
• 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
  levels.

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.

• 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.