Thread: Flushing Coolant System

Conditions inside my coolant system are horrible. I believe the original Dexcool is still in there. There is slime the consistency of jelly. Today, I decided I'd drain the system, flush it, and put regular anti-freeze in it. Serious problem--I cannot reach the radiator drain cock on the passenger side. I cannot reach the lower radiator hose where it attaches to the radiator---not even close.

Is there an easier way to drain the coolant system than disassembling the front end of the car? This is the first time in my 76 year life that I've seen such a ridiculous engineering debacle.

Just wait till you attempt the thermostat. Like you I was frustrated, needed it done and didn't have the time to remove half the car. I cut the lower hose in the middle, drained and flushed the system and reattached using a hose coupler. I have since replaced the hose, and you will need the clamp tool like this.

Sears.com

Good luck with whatever you do.

When I drained my radiator I removed the splash guard, and was able to remove the lower hose on the driver side using a pair of long needle nose pliers to reach the clamp. It's not fun, and I have replaced my clamp with a worm gear clamp to make it easier for removing later.

Where is the thermostat? Near the Coolant filler?

Originally Posted by bocoogto

Where is the thermostat? Near the Coolant filler?

The thermostat is buried underneath to the left of the front exhaust manifold, if you see the top of the lower hose, that's the thermostat housing. Pretty sure the book calls for removal of manifold to change thermostat. Back bolt is a real issue. These cars have zero space, hence the heat soaking. This motor has its own serpentine belt removal tool designed for it, although it can be done without it(search YouTube). Everything you do in this engine compartment you will lose skin over.

Today, I flushed the system. Removed both heater hoses from the alum. tubes on the engine. Stuffed a hose nozzle into a short length of rubber hose and slipped it onto one of the alum. tubes. Put a longer piece of hose on the other alum. tube. Blew water through the system until the discharge was clear. Flushed out the overflow plastic tank. Blew air through the hoses until no more liquid came out. Refilled with two gallons of antifreeze and water. All seems good. Antifreeze is clean, thermostat works fine,\. No reason to change the thermostat. changing it.

I had begun by removing the battery, thinking I could then reach the passenger side radiator hose clamp. That did not work, so two hours wasted pulling and reinstalling the battery. Changing the radiator or water pump on these cars would be major!!

I was talking to a retired GM tech , he asked what I drive and I told him. He was actually a fan of the cars, but said for these vehicles they had to basically make/modify many tools to work on these cars. Glad you got it done.