combustion in the coolant?

[Dead Parrot]

2nd on the cap releasing pressure before the radiator splits. Get a new cap even if current one is fairly new. QC could have failed.

Could be possible that you have a small enough head gasket leak or crack to let combustion air into the water spaces but not water back into the cylinder. Once the fire lights, pressures get really high, hundreds if not into the low thousands of PSI. The max for the water should be the cap rating. Test run it with full water but cap off. If there is leakage, you should see bubbles in the radiator.

Are the radiators leaking from the same spot? Maybe some assembly person needs a bit of additional training.

Nice to hear that a company stands behind their products.

[AussieinNC]

Sounds lie the tech was referring to combustion gasses leaking into the coolant.

All agree this should force the radiator cap to reach max pressure and vent out excess.

If the radiator is swelling before the cap releases, there must be something wrong with the radiator design or build.

Are you mounting the radiator solid to the chassis? If so, perhaps the frame is flexing placing extra stress on the radiator.

Here is a simple radiator test kit to check for combustion gas in the coolant.

https://www.amazon.com/Block-Tester-...YaAuw0EALw_wcB

[jerry moss]

Originally Posted by AussieinNC

Sounds lie the tech was referring to combustion gasses leaking into the coolant.

All agree this should force the radiator cap to reach max pressure and vent out excess.

If the radiator is swelling before the cap releases, there must be something wrong with the radiator design or build.

Are you mounting the radiator solid to the chassis? If so, perhaps the frame is flexing placing extra stress on the radiator.

Here is a simple radiator test kit to check for combustion gas in the coolant.

https://www.amazon.com/Block-Tester-...YaAuw0EALw_wcB

we use that same block test kit at work and it's simple and accurate.

[tregrad]

Originally Posted by AussieinNC

Sounds lie the tech was referring to combustion gasses leaking into the coolant.

All agree this should force the radiator cap to reach max pressure and vent out excess.

If the radiator is swelling before the cap releases, there must be something wrong with the radiator design or build.

Are you mounting the radiator solid to the chassis? If so, perhaps the frame is flexing placing extra stress on the radiator.

Here is a simple radiator test kit to check for combustion gas in the coolant.

https://www.amazon.com/Block-Tester-...YaAuw0EALw_wcB

I agree as well, the cap should relieve the pressure even if there are gasses in the coolant even if the cap is bad, with enough pressure to blow out the radiator you would think that that amount of pressure would override a bad spring?

Here is my radiator... https://www.coldcaseradiators.com/pr...?sku=GMT558ALS

The radiator sets on rubber on the bottom and the clamps at the top also have rubber in them.
This is in a 1972 K5 Blazer with a 2000 LS1 swap.

Thanks for the test tool link

What cap would you suggest for this radiator and set up? this is my first LS so im in the dark as what to get.