Erik N

Since my end tank started leaking on the way to 3rd Coast, I am replacing my radiator with a used unit from 928intl.

Can I burp the system by simply raising the RF corner of the car and letting out the bubble?

Also, which coolant to use?

Thanks

mickster

Seems that Zerex G-05 is the one most have recommended for the stock Behr radiator. Of course you will probably hear about 20 opinions on any fluid involving a 928!

James Bailey

The 928 cooling system is quite civilized and no need to burp.....it has built in self burping with the coolant tank being the highest point of the cooling system and a vent hose from thermostat housing to the tank. The 944 on the other hand could trap an air bubble so you needed to help it.

polecat702

Hi Erik, Mike is correct. Use the ZEREX G-05, plus a bottle of Redline Water Wetter, and fill with distilled water. I only used a gallon of coolant in my 87, and the needle stays one needle width above the first white line, A/C on or off.

Mrmerlin

there is also a bleeder from the top of the radiator to the coolant bottle.
To fill the coolant system .
with the car level fill the coolant bottle,
till the coolant will no longer fill (about 4 gallons).
Have the heater on full hot.

Then run the engine with the cap off till the fans come on or the coolant system reaches operating temp about 5 to 10 mins of running,
then replace the coolant bottle cap, and go for a 5 to 10 mile drive with the heater on,
park the car let it cool then open the cap and top it off if necessary

James Bailey

Some people seem to enjoy squeezing their hoses while the engine is warming up....gives them something to do with their hands

the flyin' scotsman

The Porsche/VW/Audi coolant is blue in colour and is designed specificaly for aluminium engines:

blown 87

exactly

Erik N

Greg-

I thought you mentioned at 3rd Coast that the reason the R upper end tank is prone to failure (as mine is) is because there is a bubble that lives there?

Mrmerlin

there is a bubble that lives on the top of the right hand tank,
since there isnt a bleeder vent .
the air pocket lets the plastic tank get brittle and it will eventually crack.

blown 87

The reasons is that is where the heat is, no way to get it out.
Let me expand on what we were talking about, the point I was trying to make is that if coolant is leaking to the outside, when it cools it will suck in air.
I have never had to really burp a 928 cooling system, even though I do sometimes to get a quicker fill.

Mrmerlin

if you want to verify the bubble in the tank,
with a removed/failed tank ,
you will see a white line about 5mm below the top of the inside of the tank,
this is where the top layer of coolant is.

blown 87

You can vacuum fill one and it will soon have a bubble there.

hacker-pschorr

G-05 I purchase in the Mercedes OEM container is specified by Mercedes for aluminum engines is piratically clear, at least compared to other coolants.

blown 87

G-05 is getting hard to find around here.
One thing I like and hate about G-05 is that if there is any leak it is easy to find due to the white residue left, but it is a bitch to clean up.