Question: My question is how hard is it to replace a radiator on a 99 Integra if I decided to do it myself? Answer: It is about a 2 hour job, I would say if you have not done this kind of work before I would leave it to a mechanic because this is kind of a tight fit and can be a bit difficult. 1) Disconnect the negative battery cable. CAUTION Do not open the radiator drain-cock or remove the radiator cap when the cooling system is hot and under pressure. This can cause serious burns from hot, pressurized coolant. Allow a sufficient amount of time for the cooling system to cool down before opening up the system. 2) Loosen the radiator drain plug and, using a large capacity container, drain the cooling system. 3) Remove the radiator cap. 4) Disconnect the upper radiator hose.
NOTE: It is recommended that each clamp be match-marked to the hose. Observe the marks and reinstall the clamps in exactly the same position when reinstalling the radiator. 5) Remove the radiator hoses. 6) Label and disengage the wiring from the thermosensors and the electric fan assemblies. 7) For vehicles with automatic trans-axles, disconnect the oil cooler lines at the radiator. Plug the trans-axle ports and the hose ends to contain the fluid and prevent contamination. 8) Remove the radiator. Be careful not to damage the radiators cooling fins while removing the unit. While the radiator is not heavy, it may be awkward. Use both hands to steady it during removal and installation 9) Installation is the reverse of the removal procedure. Refill the cooling system with the proper type and amount of coolant.
NOTE: You may need to bleed the air out of the system to avoid the possibility of a trapped air pocket that may cause engine overheating.