Mercrusier Heat Exchanger cooling tube diameter

[harleyrider116]

I have a closed cooling system on a 1984, 260 Mercruiser. Owned the boat for 20+ years and have a minimal heating up issue. I figured I'd start at the heat exchanger as I have not removed the end caps for many years and don't recall the inside diameter of the of the cooling tubes inside. Does anyone know what the diameter of the tubes inside are?? Before I go chasing around for different size brushes that may or may not fit to run thru the tubes I figured I'd ask the question on the forum....Thanks in advance....

 

[Bt Doctur]

3/16ths maybe

 

[harleyrider116]

Thanks.. I was thinking 3/16 or 1/4"

 

[Scott Danforth]

1/4" od, 0.020" wall, 0.207" ID

 

[kenny nunez]

If you find a tube that has any obstruction push it back in the direction it came from, if you try to push it in the direction of the flow there is a chance to split one of the tubes.

 

[harleyrider116]

Thanks for the responses...picked up a couple stiff bristle 1/4" diameter brushes today. Exactly what I was thinking if I find any obstructions....thanks!