Author Topic: r/r coolant - hints?  (Read 4546 times)

merrill

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r/r coolant - hints?
« on: July 31, 2005, 16:39:22 »
I am going to replace all the cooling system hoses on my 66 230.
at the same time I want to flush the system with clean water then fill the system with MB orange coolant.

I read several posts regarding air being trapped in the cooling system.  Are there any hints on how to avoid air being trapped in the system?

thanks in advance
matt
Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

hands_aus

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Re: r/r coolant - hints?
« Reply #1 on: August 01, 2005, 04:38:11 »
orange coolant? The MB stuff I bought was green and was recommended to be 1:1 with about 11 litres total. 230sl's might have a different capacity but not by much.

Take the top injection pump thermostat hose off and take the LHS heater hose off. Fill it from the heater hose that goes to the block.
Have the heater lever open and water will come out the inj pump top hose and the heater core pipe.
Fill the expansion tank, re-connect both the hoses.
Start the car and let it warm up slowly. When the thermostat opens any trapped air will force out the excess water from the expansion tank overflow pipe.

Bob Smith (Brisbane,Australia)
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Bob Smith (Brisbane,Australia)
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isofast

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Re: r/r coolant - hints?
« Reply #2 on: August 01, 2005, 10:47:33 »
Matt I often wondered the same thing. Just back from Joe and Marys home in Blacklick. Joe mentioned that in order to drain all coolant from the block there is a block drain located on the starter side of the engine that drains down the balance of fluid from what I remember Joe said that it is a very small amount left in block but none the less you mentioned all the coolant. Joe and Pete L. also recommend dropping fluid by carefully removing lower radiator hose so as not to twist off any solder from the neck of the bottom hose nipple. If you replace any hose always better to cut them off rather than try to wrestle it off. They also mention that the drain plug on radiator as on all cars are soldered in place and can twist out the solder holding thread boss. I saw at Mercedes they sell an additive for anti fouling antifreeze that is in addition to their various colored anti freeze/coolants. Although I :D  have not used it I hear that it aides anti corrosive effect of disimalar metals good luck
Ernie

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isofast

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Re: r/r coolant - hints?
« Reply #3 on: August 01, 2005, 10:53:25 »
Oh I forgot Joe also mentioned dont fill and drive but that you fill then run the car a little shut it off let it cool then refill some more and then start run for another short period with heat levers on and off and refill. Bob P. mentioned pinching off one of the coolant tank and or heater hoses while squeezing large upper hose (with gloves on so as not to burn yourself to burp the air from your baby. 8)

First Place AACA Show Winner 350SL July 2003
I love low mile Mercedes.
First Place AACA Show winner for 2004 280SL
1969 280 4spd Papyrus White

rwmastel

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Re: r/r coolant - hints?
« Reply #4 on: August 01, 2005, 22:30:35 »
Does anything in here help?
http://www.sl113.org/articles/default.asp

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420
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bpossel

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Re: r/r coolant - hints?
« Reply #5 on: August 02, 2005, 04:24:41 »
Matt,

The way I have done this, and it seems to have worked well for my car is to move the heater levers to the full heat position.  Then disconnect the heater hose from the firewall on the drivers side (after draining the fluid).  Connect a small extra section of hose to the outlet on the firewall and point this downward.  With the heater hose section still connected to the engine, put a small funnel on the end of the hose and slowly fill with new radiator fluid.  Either get another person to hold up the funnel end while you pour, or you can tie it up with a small piece of wire.  Pour slowly.  Eventually the fluid will start to come out from the extra section of hose connected to the firewall side.  Although, I have also had my overflow tank overflow before the other.  Not sure why, but if the later happens, try to catch this before it happens.  This means once in a while, look in your overflow tank while you are filling.  Stop filling when the overflow is ~ ½ full.

Reconnect heater hose from engine to firewall.  Start engine and let warm to operating temp.  With a glove on, squeeze the large top radiator hose with your right hand.  While holding the squeezed hose, use your left hand to pinch off the small hose connected to the overflow tank (use a flat smooth pair of pliers, ie. Needle nose pliers to pinch small hose).  Now release the large hose while still pinching the small hose.  You will hear the system suck water back.  Do this procedure several times.  You will notice the fluid in the overflow tank go down a bit.  This means that the air is out.  Sometimes it also helps to park the car on a slight incline, front higher than the back.  The goal is to ensure that no air is trapped in the system.  This extra air, can and will cause overheating, whereas the thermostat doesn’t work as designed with air trapped in the system.

Good luck!
Bob

bpossel
Memphis, TN.
1971 280SL
1997 E320

Naj ✝︎

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Re: r/r coolant - hints?
« Reply #6 on: August 02, 2005, 04:38:06 »
May be worth considering back flusing the system after draining.
There us a write up on this site explaining how to do it (Help Rodd  :(  ).
I had to run the water for about 10-12 minutes before I got clear water coming out.

naj

65 230SL
68 280SL
68 280SL