Radiator flush

[Loren]

Yes, you need to bleed the air out of the system.

[996noob]

Yes, you need to bleed the air out of the system.

If I do a complete drain of the radiator send and return lines, should I drain the pair of hoses from the front, or from the rear (closer to engine)? Which are the correct points to undo the hoses for complete drain?

[Loren]

Draining coolant

1. Position the vehicle at the take-up points provided on a lifting platform.

2. Open hood.

3. Open tank cap on the expansion tank and remove.

4. Remove the entire underbody cover.

5, Drain cooling system. Remove the drain plug from the engine, drain the coolant into a container and dispose of coolant according to the country-specific legal requirements if no longer required.

6. Pull the radiator supply and return lines off the engine. To do so, undo the hose clamps, carefully pull off the hoses and allow the remaining coolant to run out. Then clean the inside and outside of the hoses, connect the hoses again and tighten the hose clamps. Check whether the hoses are securely seated.

7. Open the heating lines on the vehicle floor. To do so, open the hose clamp, pull off the lines and drain. Then clean the inside and outside of the hoses, connect the hoses again and tighten the hose clamps. Install the hose clamps and check that the lines are seated correctly.

8. Install drain plug on the engine with a new sealing ring and tighten. Tightening torque: 10 to 15 Nm (7.5 to 11 ftlb.).

I highly suggest the refill using a tool like the UView 550000 Airlift Cooling System Leak Checker and Airlock Purge Tool Kit (under $100).

[1schoir]

Yes, you need to bleed the air out of the system.

If I do a complete drain of the radiator send and return lines, should I drain the pair of hoses from the front, or from the rear (closer to engine)? Which are the correct points to undo the hoses for complete drain?

If you drain from the rear (closer to the engine), you should get a more complete drain as those hoses are lower at that point than at the front.

When I did a complete drain and flush, I attached a hose to one of the hoses at the rear and made a temporary seal at the garden hose nozzle and flushed it until the water coming out of the other hose right next to it was clear, then drained it thoroughly.

Don't forget to drain and flush the two small hoses that are behind the battery, leading to and from the heater core, and leave the heat setting on high.

Regards, Maurice.

[996noob]

Draining coolant

1. Position the vehicle at the take-up points provided on a lifting platform.

2. Open hood.

3. Open tank cap on the expansion tank and remove.

4. Remove the entire underbody cover.

5, Drain cooling system. Remove the drain plug from the engine, drain the coolant into a container and dispose of coolant according to the country-specific legal requirements if no longer required.

6. Pull the radiator supply and return lines off the engine. To do so, undo the hose clamps, carefully pull off the hoses and allow the remaining coolant to run out. Then clean the inside and outside of the hoses, connect the hoses again and tighten the hose clamps. Check whether the hoses are securely seated.

7. Open the heating lines on the vehicle floor. To do so, open the hose clamp, pull off the lines and drain. Then clean the inside and outside of the hoses, connect the hoses again and tighten the hose clamps. Install the hose clamps and check that the lines are seated correctly.

8. Install drain plug on the engine with a new sealing ring and tighten. Tightening torque: 10 to 15 Nm (7.5 to 11 ftlb.).

I highly suggest the refill using a tool like the UView 550000 Airlift Cooling System Leak Checker and Airlock Purge Tool Kit (under $100).

Thanks, Loren. Once again, superb stuff.

Yes, I'm awaiting the Uview, should arrive any day now!

[996noob]

Don't forget to drain and flush the two small hoses that are behind the battery, leading to and from the heater core, and leave the heat setting on high.

Regards, Maurice.

Do you mean undo the heater core hoses that are located in the battery area in front of the windshield?

Do you also put the ignition on, and Heater on high, while doing the flush right in the battery compartment area?

[1schoir]

Don't forget to drain and flush the two small hoses that are behind the battery, leading to and from the heater core, and leave the heat setting on high.

Regards, Maurice.

Do you mean undo the heater core hoses that are located in the battery area in front of the windshield?

Do you also put the ignition on, and Heater on high, while doing the flush right in the battery compartment area?

Yes, it's those two heater core hoses behind the battery. If you look at them closely, you will see an arrow on one of the hoses indicating flow into the heater core, and the other hose will have an arrow indicating flow out. I also put the garden hose into the hose with the "in" arrow and observed water coming out of the other hose until it was clear.

Here is a photo of two places where those arrows are viewable, one on the hoses and one on the foam cover that protects the heater core:

You can undo the clamp at the bottom end of those hoses, just behind and a little above the battery tray to flush out the core with a hose:

I also flushed down into those two tubes.

You want the heater on high so that the valve is completely open.

Regards, Maurice.

[996noob]

Thanks Maurice, I'll rememebr to do that.

[ard.]

Comment/Question:

When people refer to a "50/50" mixture, this should be one half distilled water, one half antifreeze, correct? Or say one gallon water mixed with one gallon antifreeze to yield two gallons of fill. Yes?

I noted some prior math that seemed to diverge from this....

Thx

Adam

[1schoir]

Comment/Question:

When people refer to a "50/50" mixture, this should be one half distilled water, one half antifreeze, correct? Or say one gallon water mixed with one gallon antifreeze to yield two gallons of fill. Yes?

I noted some prior math that seemed to diverge from this....

Thx

Adam

Adam:

50/50 mixture for coolant is one half distilled water and one half antifreeze, same with the gallons!

Regards, Maurice.

[c337cc]

Just out of general interest: Why do you want to change the coolant, considering that it's a lifetime filling and, at least according to Porsche and the coolant manufacturer, does not need to be changed?

Cheers,

Uwe

No such thing as liftime fill. Just a sles gimmick. I will believe that ,when they give me a lifetime warranty on all the components, that have a life time fill.

Howard

Porsche Tech since 1978

[c337cc]

My coolant is 6 years old next month. It is neither dirty or broken down. I test it at least once a year and it has not lost any of it's cooling properties. Unless you have a leak or somehow dilute the mixture too much with water I see no reason to change it.

Whats the ph of your coolant???

[B_Zerpersande]

On 5/29/2005 at 0:54 AM, 1999Porsche911 said:

1. Remove the coolant tank cap and remove the coolant screw and allow the 2 gallons to drain from the engine. 

2. Turn off the car and repeat #1 three more times.

YOU COOLING SYSTEM IS NOW ABOUT 90% PURE WATER

3. Repeat number 1 but this time, fill the tank with a 50/50 mix of water .

My plan was something like yours.  Except I am going to flush the entire system repeatedly with tap water.  After this a radiator flush will be added and then the entire system flushed again with tap water.  I will then repeat the flushing process using about 15 gallons of distilled water.  Yes, this is overkill, but with only 20L boxes available, I decided that two additional cycles will make sure there is essentially nothing but distilled water in my system.  I'll then use your 50/50 and full concentration meyhod.  It won't be exactly 50/50 but it will be close.  

 

Thanks for the post bc your idea really firmed mine up.

[Ahsai]

There's a very simple way to flush the whole system.