antifreeze overflow problem

[recon]

I've finally got my Deuce! It's insured and passed NY inspection. However,after the first ride of 6 or 7 miles I parked it and shut it off and antifreeze started running out of the overflow tube. Maybe about a cup or so. Any suggestions on what the cause and cure can be? Also, the oil pressure gauge was reading normally and now is close to 60. If I rap it, it will go back to normal for a while. Ideas?
recon
dutchess county, ny

 

[WillWagner]

Too much coolant, pushing it out to find it's level? Radiator cap failed? Ground issue for the gauge.

 

[devilman96]

Run it up to temp a few more times (2-3) and see if it continues to do so... If so change the cap (see parts cross)... If it continues after that repost, ya might have some issues. Mostly ... WATCH your gauge until ya figure it out!!!

 

[JDToumanian]

My truck did the same thing when I got it, radiator cap was bad. I could see the crack in the rubber washer. I got my "new old stock" cap from Saturn Surplus and the problem was cured.

Regards,
Jon