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Model Specific Questions and Info => MK2 Golf/Jetta and Audi 5k => Topic started by: thomas m on June 18, 2017, 04:47:02 pm

Title: MK2 1.6 NA Diesel Coolant Replacement
Post by: thomas m on June 18, 2017, 04:47:02 pm

I'd like to do a quick drain and refill of my coolant without removing the v-belts and power steering pump. My thermostat was replaced a short time ago.

It says to release the 2 hoses shown in the figure at  #1
Will the heater core (in the cabin) drain if the Bentley procedures are followed?
Will the block drain completely as they say??



Also, they say to refill via the overflow bottle. Will that work and fill the engine completely??

(https://c2.staticflickr.com/4/3686/13611077713_5d0ff969c4.jpg)

Title: Re: MK2 1.6 NA Diesel Coolant Replacement
Post by: vanbcguy on June 19, 2017, 12:42:42 pm

If you pop both of those hoses off you can get most of the coolant out. Be sure to remove the cap from the expansion tank!

Yes, you can fill entirely from the expansion tank. It is the high point in the system. You'll want to fill it up then fire the engine with the cap off. You'll need to continue topping it up as air is purged from the system. The small hose to the top of the expansion tank is responsible for purging air from the system, you should have a good stream of coolant coming through it. You'll see the air bubbles come out that way too.

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Title: Re: MK2 1.6 NA Diesel Coolant Replacement
Post by: thomas m on June 27, 2017, 06:39:44 pm

I decided to pull and replace the thermostat. Issue with that in a separate posting.

With that out, I coaxed a little more fluid out by jacking up each side.

I also back-flushed the heater core and radiator.

I filled the block through the cylinder head, then filled through the bottle as it took fluid.

Thanks for the tips.

Title: Re: MK2 1.6 NA Diesel Coolant Replacement
Post by: air-cooled or diesel on July 05, 2017, 12:17:28 pm

i find heater core is high in system and wont drain, i take hose off return hard line, and blow some air thru it, use mouth, compressor could blow core, and you find water/coolant will push out of core. a little better of a result.
^:that is with drain already open.

Title: Re: MK2 1.6 NA Diesel Coolant Replacement
Post by: thomas m on July 05, 2017, 08:15:20 pm

Quote from: air-cooled or diesel on July 05, 2017, 12:17:28 pm

i find heater core is high in system and wont drain, i take hose off return hard line, and blow some air thru it, use mouth, compressor could blow core, and you find water/coolant will push out of core. a little better of a result.
^:that is with drain already open.

Thanks, Aircooled !!
I did that and while at it I backed flushed the heater core (and radiator) with water being careful not to pressurize them, just move any crud out.
I used my shopvac hose attached to the radiator out hose to siphon water back through the radiator. The heater core was easier.