: 79 deville 425 coolant capacity??



vicello93
05-22-13, 12:49 AM
Anyone knows how many QTs of coolant it takes on a 425? Thanks in advance!

1980coupe
05-22-13, 12:58 AM
It should say in your owner's manual if you have it. Towards the back

lacville78
05-22-13, 01:55 AM
Service manual says 19.8 quarts, so that's about 5 gallons. Make sure if you're not getting premixed, to use distilled water!

1980coupe
05-22-13, 05:50 AM
Distilled water?

MoistCabbage
05-22-13, 07:32 AM
Yes. No minerals to cause corrosion. Plus, you'll only need to buy half the coolant.

1980coupe
05-22-13, 09:49 AM
I have always used water from the garden hose or from inside the house and never had any issues. I usually buy the full strength and then just add water to it

vicello93
05-22-13, 10:04 AM
Yeah I alway bought the 50/50 mix actually:) thanks a lot for the info!

lacville78
05-22-13, 05:47 PM
I have always used water from the garden hose or from inside the house and never had any issues. I usually buy the full strength and then just add water to it

Not good at all! It sucks replacing freeze plugs, and regular water will corrode them. Plus you can get distilled water at the store for around a dollar. There is really no good reason at all to use regular water.

vicello93
05-22-13, 10:25 PM
So I changed the radiator, thermostat and gasket, all went good! Just the thermostat housing back bolt that was a pain to get it out and in but I got it. Thanks for the info!

The Ape Man
05-24-13, 08:44 PM
There may be something to using distilled water but the whole entire planet used tap water mixed with antifreeze for many years.

Dissimilar metals pretty much ensure something is going to corrode over time.

I used to use 3 gallons antifreeze and top off with water on these cars.