Coolant system Maintenance

[Cobrasrfun]

I have a MK 3 with a 351W. FFR aluminum radiator, Moroso 1 quart tank with a recovery tank. I want to replace all the hoses and coolant. Is there anything I need to know about refilling the system to avoid any air pockets.

[Paparazzi]

I have a MK 3 with a 351W. FFR aluminum radiator, Moroso 1 quart tank with a recovery tank. I want to replace all the hoses and coolant. Is there anything I need to know about refilling the system to avoid any air pockets.

I'm still officially in the go-kart stage, but when attempting to burp my 351W before first start I had a hell of a job. After some research, I read a hint to remove the temperature sender and gently squeeze the lower hose whilst topping up from the cap. This worked for me and was the only way I could get the air out. Leaving the temperature sender plug in I felt I was getting nowhere.

[durk]

The heater on my car is the highest point in the cooling system an I have bled the air off at that point by disconnecting the longest hose with good results.
Also if you use Evans waterless coolant it eliminates a host of problems such as over pressurization, lifetime coolant, no corrosion to aluminum

[CraigS]

Durk has a good suggestion. To expand on it a bit: If you have a heater remove the hose where it connects to the intake manifold. Fill they system at the T-filler unitl it comes out of the manifold, then install the heater hose. If no heater, remove a temp sensor. Either one of these lets air escape while the coolant goes in so filling is much faster. Once the hose or sender is replaced try to get a little more coolant in. When it's as full as you can get it put the pressure cap on the filler, fill the over flow tank 2/3 and warm up the engine. I usually go to about 200 deg and shut it down. As it cools make sure the overflow tank doesn't empty as coolant is sucked back into the engine. After 2-3 cycles, you should be good to go.

[Jeff Kleiner]

On the ones I do I add petcocks to the rear coolant ports on the intakes:

http://i269.photobucket.com/albums/jj43/jkleiner/petcock.jpg

No need to remove any senders or hoses; when filling simply open these as well as the one in the upper corner of the radiator until coolant starts to come out. Close 'em, top it off, start it up and what little air remains purges through the recovery tank. Quick & easy!

Jeff

[CraigS]

Jeff that is a great idea. I think I will do that. Crap, my intake has cast bosses there but they are not drilled and tapped. Oh, well, next time the intake is off.

[seagull81]

This also works really well.
http://www.amazon.com/UView-550000-Airlift-Cooling-Checker/dp/B0002SRH5G/ref=sr_1_6?ie=UTF8&qid=1453733788&sr=8-6&keywords=radiator+bleeder

[bcovell]

The Evans waterless coolant mentioned by durk is a great product, I use it in my Monster Miata (Ford 331 cu V8). The boiling point is 375F. Only problem is the cost and the fact that all water needs to be removed from the engine block first.

[Bigtim01]

You might want to install an anoide in the cooling system.
http://www.summitracing.com/parts/flx-32060?seid=srese1&gclid=CJDJ0c653soCFQEnHwod3cAP0w
HTH
Tim

[cgundermann]

Going to add Jeff's recommendation for a petcock exactly where he did on the EFI motor picture; and depth/clearance permitting add the anode on the other side. Flex-O-Lite indicates anywhere in the cooling system. Found a 3/8 NPT petcock at Summit and using a stepdown adapter (3/8 to 1/4) for the anode.

[KDubU]

On the ones I do I add petcocks to the rear coolant ports on the intakes:

http://i269.photobucket.com/albums/jj43/jkleiner/petcock.jpg

No need to remove any senders or hoses; when filling simply open these as well as the one in the upper corner of the radiator until coolant starts to come out. Close 'em, top it off, start it up and what little air remains purges through the recovery tank. Quick & easy!

Jeff

Brilliant idea Jeff, tks!

[chopthebass]

Is a petcock something I can get from a plumbers store or is it an automotive product? Never heard the term. I'm not from round 'ere!

[cgundermann]

For this application, it is automotive - ordered mine from Summit Racing. You would need to see if you have a NPT plug at the back end of your lower intake. My Edelbrock EFI lower had two NPT tapped plugs installed. They were 3/8 NPT fittings; if you don't know - here is how you measure and convert to NPT sizing:

52129

[chopthebass]

Ah the location in Jeffs photo I have filled with a sensor. EFi I think. Not sure if there is a petcock with hole for sensor. Shame, I like his idea.

[Jeff Kleiner]

You can usually find these petcocks at a well stocked hardware store.

Ian,
The rear ports of the intake are generally not a good location for a sensor---these passages are dead headed with no flow so any coolant temperature readings from here will not be especially accurate.

Jeff

[chopthebass]

Jeff,

Doh! I should have looked more closely. That's the bellhousing end! If that was the front of the engine, my sensor is where you circle in the pic!.