About 2 weeks ago, I flushed my coolant. Took off the upper and lower radiator hoses and heater hoses and flushed with the inline T flushing kit. I used hose water with low pressure. I did NOT use any flushing chemicals, clean water only. Flushed the radiator, heater core, block, and then put water down the upper hose and washed out the pump. I then refilled with a 50/50 mix of the Prestone Dexcool and fresh water. I burped the system and checked it a few times after driving, everything is at the proper level. I have not had any overheating issues. There did not appear to be any stop-leak in the old coolant that came out of the engine. It was old but didn’t look terrible.

I did not have a single leak or drip before this. I meticulously inspected for leaks several times after I bought the van and there were zero coolant leaks anywhere.

Now two weeks after the flush, my water pump is leaking from the weep hole, there is a leak between the thermostat housing and the water pump, the heater valve body (not hoses) is leaking, and the radiator cap is leaking fluid (yes I removed/retightened it). All these leaks are orange and definitely coolant. None of the coolant hoses are leaking at any connections. This can’t be sheer coincidence. What is going on here?

 

did the old coolant have a leak stop product in it?

 

maybe your radiator is blocked.

Try taking off the top and bottom hose, and running water through it.

Or, get the engine up to operating temp, and measure the temp at the inlet and outlet with an infarared thermometer.

 

It did not appear to, I specifically checked it and didn’t find traces of anything.

 

I eventually got the rest of the gallon in with heat cycling, just had to work the air out. I did flush the radiator from top to bottom with the hose and did not see any indication of blockage. I’ve had no overheating issues and the coolant tank is still exactly at the fill line.

 

is this with a new water pump? you mentioned replacing it in another topic.

 

Nah the old one. The new one is on the way.

 

I guess I would find out why the thermostat housing and heater valve are leaking. Are there cracks, or did the gasket fail etc. That would provide clues. The cap can be replaced cheaply.

 

I ordered a new radiator cap and the new water pump comes with the new thermostat and housing installed, so at least those 3 things will be fixed at the same time. The heater valve I'm not going to replace just yet as it's a very small (but relevant) leak. I just can't imagine how all these leaks could appear at exactly the same time right after a coolant flush when it wasn't leaking a drop anywhere before.

 

Probably had a a bunch of crud built up over the years that was kind of acting as a sealant. Washed it away revealing the weak spots in your system.