IMPORTANT! Please read before installing radiator


An electrical current passing through the coolant can cause engine and cooling system component failures due to problems from electrical ground and the generation of static electricity elsewhere in the vehicle. This can destroy an engine and other cooling system components regardless of the quality of cooling system maintenance. The only way it can be stopped is to correct the electrical problem causing the current. Damage resulting from an electrical current can be pitted liners, pitted oil coolers, pitted radiators, extreme aluminum corrosion, abnormal water pump failures and head gasket failures.

How to test for electrolysis

A multimeter or voltmeter capable of reading both AC and DC currents is required to test cooling systems. The meter needs to read zero to the maximum voltage of the system being tested in tenths of a volt. The meter leads must be long enough to reach between the coolant and the groundside of the battery. An ohm function of a multimeter is very helpful to pinpoint areas of resistance in as electrical system that will cause an electrical current to ground through the coolant rather than the engineered electrical circuit

You will need to refer to the manufacturer’s recommendation for allowable voltage. If no specs are called out, voltage of zero to .3 is normal in a coolant of a cast iron engine. Such an engine will be destroyed with time by .5 volts

Be particularly careful of starters. They can cause as much damage to an engine as a direct connection to an arc welder due to the amperage present. And 4130 is a poor conductor for a chassis ground, wire to the battery.

The above procedure will test a complete system except for an electrical current, which can be generated by the rear end transmission. This is particularly true with air bag suspensions, rubber pad suspensions and rubber-mounted transmissions. Any current generated will travel up to the drive shaft to ground through the engine coolant. Grounding rear ends and transmissions is strongly recommended.

Always change the coolant if a current is detected. The electrical current will destroy the protecting chemicals in a properly inhibited coolant.

  1. Attach one meter lead to the groundside of the battery.
  2. Install the second lead in the coolant touching the coolant only.
  3. Read the DC and AC voltage with all systems off.
    1. If a block heater is present, also take a reading with the heater turned on.
    2. If an automatic battery charger is present as a standby system, also take a reading with this system running.
  4. Read the DC and AC voltage with the electrical starter engaged.
  5. Read the DC and the AC voltage with the engine running and all systems turned on: lights, coolers, fans, heaters, air conditioning, cell phone, two-way radio, including the phone and radio on both standby and transmit.
  6. If the coolant shows an electrical problem with all the equipment turned on, turn off one system at a time until you finally turn off the system that stops the electrical current. When the current stops, this will indicate the electrical system causing the problem. The current will be AC if the problem is due to static electricity.

Installation Information

***Caution! Never remove the cap off a hot radiator. The coolant is under pressure and is hot enough to cause serious injury. Wait at least three hours for it to cool down.

  1. Completely flush the cooling system before installing your new radiator. This will help keep foreign matter out of your system at radiator installation. Cooling systems require a thorough flush of the radiator, engine, overflow tank, hoses and heater core. Failure to do so will lead to mixing coolants and contaminates and creates a corrosive cocktail for the radiator.
  2. For street use: use a new, quality coolant and follow the manufacturer’s instructions. For racing use only: use distilled water. Straight water is the best medium for transferring heat. If using additives in your cooling system, follow the manufacturer’s installation instructions. Not following their instructions could ruin your radiator.
  3. Use a new radiator cap with the correct pressure. A pressure relief cap should be installed that will hold 17-19 lbs. for street use. 19-24 lbs. should be used for racing only. To order, please visit our website or give us a call at (800) 842-5166.
  4. Avoid brass parts in the cooling system, if possible. Brass and aluminum react to each other and cause electrolysis. Electrolysis strips away metal at the inside of your radiator and eventually creates leaks. Dissimilar metals, contaminants and improper maintenance of the cooling system can lead to failure in the radiator.
  5. Do not ruin your new radiator by improper filling! It is very important that your engine be completely full. Aluminum radiators must not be subject to pressure surges that result from air pockets in the engine. When air surrounds a cylinder or area next to a combustion chamber, the metal becomes very hot. When water comes in contact with the hot metal, a volume of steam is produced that is larger in pressure than the cap can release. The resulting pressure bulges the tubes in the radiator and reduces the airflow and cooling capacity.
  6. Grounding rear-ends and transmissions are strongly recommended. An electrical current can be generated by the rear-end transmission. This is particularly true with air bag suspensions, rubber pad suspensions and rubber-mounted transmissions. Any current generated will travel up to the drive shaft to ground through the engine coolant. Grounding rear-ends and transmissions are strongly recommended.
  7. Test for electrolysis – please read and follow the attached Testing for Electrolysis sheet. In addition, we offer grounding kits to help you avoid electrolysis issues please see our website or call one of our sales staff at (800) 842-5166 for more information.
  8. Wrap overflow tube and pipe thread fittings in Teflon tape. Strait thread fittings should have good quality anti-seize compound added to the threads prior to installation.
  9. Use a recovery tank – keeping air out of the system can help reduce the risk of pressure spikes and corrosion, which can ruin a radiator. We offer a wide selection of recovery tanks, please visit our website or call one of our sales staff at (800) 842-5166.
  10. For Ron Davis Racing Products Fan-Equipped Radiator Models:
    For easy wiring of our fans, we offer single and dual 185 degree or a 195-degree fan harness kits with built-in relay and fuse. The kit includes high quality wire with labels, a 3/8 NPT stainless steel thermostatic switch, 40 Amp relay, fuse holder and supporting hardware and instructions. Call now to place an order (623) 877-5000.

Mounting Information

Non-Racing Radiators

  1.     Custom radiators – Chassis flex can ruin your radiator, saddle type mounts can help absorb this. The lower mount should be under the tanks only; this is the strongest part of the radiator. The upper mounts should be at the ends of the core or where the tanks weld to the core.
  2.     OE Performance Type Radiators – These may have flanges that bolt the radiator in solid. Fresh rubber grommets or vibration isolators (40 durometer) should be incorporated into the mounting of the radiator to absorb chassis flex.

Racing Radiators Only

  1.     Install a screen or air box in front of the radiator to keep debris from damaging the core or obstructing the airflow.
  2.     Seal front perimeter of the radiator to the inlet to force all the incoming air through the radiator. Radiators will not work without the proper airflow and air will always take the path of least resistance.


  1. Change coolant per coolant manufacturer’s instructions.
  2.  Keep the core clean – use water only to wash the outside of the core. Warning: a high-pressure washer will bend the fins and damage the radiator.
  3.  Keep the fins strait. Bent fins restrict air flow reducing cooling performance. The fins may be straightened very carefully with a small pocket screwdriver.
  4.  Test for electrolysis – please read and follow the attached instructions titled ‘Testing For Electrolysis’. We offer grounding kits to help you avoid electrolysis issues as well, please visit our website or call one of our sales staff at (800) 842-5166 to order.
  5.  Replace the cap every 2-3 years.