The Definitive Guide to Radiators

[EVO-V]

Part 2: Do I have my radiator repaired or replaced?
This is a very common question given the proliferation of services available in most road-side radiator repair shops.

The first thing that needs to be asked is, what kind of damage are we looking at?

1. There's a crack on my radiator's plastic tank, do I repair or replace?

If the crack is on the plastic tanks it can be repaired with high temp wet curing epoxy.

If the crack is on the inlet or outlet pipe -replace it.


2. There's a leak on the tank of my copper-brass radiator, do I repair or replace?
If its a crack or a ding on brass tanks, it can be repaired with solder.

If the leak is around the inlet/outlet pipes, and as long as the joint is reasonably intact, you can still have it repaired.

But you will want to check why this happened. A leak on the pipe means that the hose may be improperly installed.


3. There is a leak in the middle of the core of my aluminum radiator. Do I have it repaired or replaced?
Sorry, even if aluminum tubes are thicker, it is impossible to weld them without destroying them.


4. There is a leak in the middle of the core of my copper-brass radiator. Do I have it repaired or replaced?
If the leak is a puncture on the broadside of the tubes, the side adjacent to the fins, it is repairable. However if the puncture is on the radius of the tube, attempting to repair this may result in the damage spreading as the material expands under the heat of a torch.


5. But the road-side radiator repair guy says he can fix this. Should I or should I not?
In larger applications, wherein radiators 1 meter x 1 meter in size are involved, it makes economic sense to replace the whole tube to salvage the radiator. This needs to be done by a vendor with access to virgin tubing.

The "expert" from the road-side repair shop, however, will likely "condemn" the tube by sealing it on both ends with solder. It will get it working...however, the integrity of radiator cores function on symmetrical equalization of pressure. Meaning all the tubes and fins exert the same amount of pressure against each other. If one fails, the rest cascade.

The problem here, is that without coolant flowing through the tube, said tube will not be able to resist the expansion of the fins adjacent to it, as they are pushed by the pressure inside

Eventually this will cause the rest of the core to fail as the other tubes/fins expand towards the point of weakness. The fins will eventually detach from the tubes and the radiator will destroy itself.


6. But isn't it cheaper to simply have my radiator repaired/overhauled than to get a new one?
First of all a properly maintained coolant system, will ensure that you would not need to "overhaul" your radiator.

Second, we need to talk about the difference between cost and value. For the purposes of discussion, cost is generally what you put out at the time of purchase while value is generally the utility you derive from said purchase.

It is natural for us to opt for the cheaper solution, often so we grow up thinking we should find the best deal without realizing that there is more than just the price tag attached to every decision.

Cost-wise repairs are cheaper -generally and are recommended in certain situation over replacements.

However, value-wise, factoring in the risk for later rework ie. more downtime, lost income, inconvenience, risk of engine damage, whatever you think you're saving is starting to look rather foolish.


7. What is this overhaul thing I see everywhere and would you recommend it?

Overhauling is generally an attempt to "restore" a radiator to a functional level of use. In most situations wherein motorists/mechanics/pseudo-scientists etc. do not take care of their coolant systems, they end up clogging radiator tubes. (Will have a more indepth discussion about this in Part 3)

Servicemen will open a radiator and stick a rod or a piece of wire to scrape off sediment and residue from the inner surface of the tubes. In so doing, abrading tube walls making it more prone to leaks.

Larger radiators for industrial use, have thicker tube walls, and are therefore more suitable for this process.

If your radiator has been brought down once for an overhaul, and no root cause analysis is done nor the appropriate remedy applied, it is more likely to be brought down again at a far shorter interval or result in catastrophic failure.

It is clogging for a good reason.


8. If I were to replace my radiator, which should I choose? Copper-brass or Aluminum?
As stated in part one, it doesn't matter as long as the radiator you choose is designed correctly.

Your cooling system, however, is worth investing in for the long term.

Special considerations only come in if your applications for your vehicles change for more extreme, heavy and/or extended use conditions.