Catastrophic External Coolant Leak - Toyota Prado J90 [FIXED]

Toyotas are known to be trusty and reliable. And I can vouch for this, backed by my own personal experience. However, no car is indestructible, and my trusty 26 year old Toyota Prado Landcruiser is no exception.

One fine morning a couple of days ago, I had just parked my car in the company car park, ready to face yet another pencil-pushing day (or modern equivalent, since we've long since gone paperless and pencils were only used by old school die-hards like myself). As I walked out in front towards my office, there was a sudden gush of water coming out from under the hood, on to the floor below. If my Prado were a pregnant woman, I'd say it was time to rush to the hospital for a "happy birthday"....

I knew this could only mean one thing - coolant leakage. Or rather, based on the sheer volume of water, something must have burst somewhere. Since there was nothing I could have done, as things were still hot as I had just shut off the engine, I proceed on into the office. It was only in the evening, after office hours did I return to look into the engine bay.

Upon popping the hood, I confirmed that there was no visible remains of water in the radiator, and in the coolant reserve tank either. As there was just water and not steam gushing out earlier that morning, and my car did not overheat during the drive to office, I guess it just coincidentally happened while I was in the car park. Lucky nothing happened in between, as there was really no where convenient to stop along the way.

None of the hoses looked ruptured or decoupled, so I called up my family mechanic, David to help come and take a look. As my car was INSIDE the company, did some alignment with security. Fortunately, security personnel were very nice and supportive - this wasn't their first experience.

David came to take a look. After pouring in some water into the radiator, immediately a stream of water came shooting out from the side of the engine. Fortunately, it was the coupling that connected the thermostat to the hose. Fortunate, I say, as that was fairly easy to replace - provided the part was available in stock and nothing else was leaking. David ordered the part, but we had to wait to today to get it fixed, as it was raining every day. In fact, this morning it was drizzling, but we figured out we had to get it done today, as the company premise was less crowded on weekends. Plus, I didn't want to leave my car there any longer, as that would mean I'd take up 2 parking bays in our already-congested parking lot....

Hose to radiator and thermostat coupling removed (left arrow), revealing the thermostat (right arrow) above the alternator.

It was a quick job, removing the coupling which had a nasty ~2mm hole, as long as replacing the hose. Once done, David filled up the radiator with water. After starting, everything checked out ok - no sign of leaks elsewhere!

This wasn't the end of it - we still had to counter-check and fill up with coolant (as we only used water for now), and so David drove my Prado back to his workshop. Besides, it was time for the regular service maintenance. A word of advice to everyone - no matter which car you are driving, never skip your regular maintenance or use sub-standard / imitation parts. That's a false economy that will come back to bite you some day....

And there you have it, all done in just under an hour. A very big thanks to the management and officers of the company security for their help and facilitating the on-site repair operation. I will share my experience with my team and colleagues - in case any of them find themselves in an unfortunate similar situation.