piston/pin press method

monk-monk

Chief Petty Officer
Joined
Aug 27, 2006
Messages
642
I've been working on a 1978 mercury 1400. I've got new piston assemblies and i've been reading my Merc manual about steps for pressing the new piston pins in place. Mercury talks about heating the piston dome with a "torch lamp" to a temp of 190 degrees before pressing pin in place...What is the hot tip/method for pressing these piston pins...how's everybody else do it now days..??
 

1fishbone

Chief Petty Officer
Joined
Nov 9, 2010
Messages
476
Re: piston/pin press method

Use an oven to heat the piston, it sounds like the manual is referring to a heat lamp.
 

arsenalpsu

Petty Officer 1st Class
Joined
Dec 1, 2008
Messages
290
Re: piston/pin press method

If you're talking about the snap ring, it's not really necessary to heat the piston. Just press them in there as best you can with your thumbs, just enough for them to stay in and not snap out, then take an old piston pin rod and place it on the ring and gently tap with a rubber mallet and it should snap right in. It does take a bit to get the hang of and your thumbs will be sore when finished!

If these are new pistons the pin will slide right in very easily. If you are removing old ones you'll have to hammer them out with the appropriate size deep socket, and work then in the same way. Heat shouldn't be necessary.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,589
Re: piston/pin press method

Like arsenalpsu posted, the newer aftermarket pistons needs no heat only the OEM style.
 

monk-monk

Chief Petty Officer
Joined
Aug 27, 2006
Messages
642
Re: piston/pin press method

My pistons are factory mercury pistons w/ keystone rings...the pin will not just push in...there is an interference fit...OR i wouldn't have asked the question!!!...LOL...!
 
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