3126 Aftercooler headache

[Njlarry]

This applies primarily to CAT 3114,3116 and 3126 but maybe other CATS too. With a lot of info from this site I got the courage to remove, take for cleaning and pressure testing my port aftercooler. The only written CAT instructions I could find was "Disassembly and Assembly 3114, 3116 and 3126 Engines" CAT SMCS 1063-011. Use of RTV was not mentioned and although I have read here and elsewhere about it, I forgot to do it after three days work!
I don't think there was any RTV on it when we removed it. I have a pic of it on my phone but it won't let me share it by email to myself so not sure how to post it here. All I can see is a weld on the ends. The RTV I believe is supposed to go next to that weld. Not sure what it actually does to the airflow. Others have mentioned that they have seen many ACs without RTV there.
The fun never stops.
Will my screwup totally mess up my engines? How critical is that RTV ?
Sorry I couldn't post the pics but both the aftercooler and heat element unit looked very clean to start with.
Thank you for all your help and wisdom.

 

[Strecker25]

It helps the air from bypassing the AC core so it overall helps with the effectiveness of the aftercooler reducing the charge air. I’m not sure just how much of an effect it will have though

here’s ours with the new rtv

 

[Njlarry]

Thank you. Do have a pic without it? I could be mistaking a weld for old RTV but I don't think so.

 

[Strecker25]

Best I have, still with rtv. sorry…

 

[Strecker25]

This is another with the silicone before I had them dipped, the black part is sealant

 

[dtfeld]

I guess the question is was there RTV in these from the factory and is this the recommended solution from CAT? Or is this something that is done because there was a couple pictures floating around the internet, and it seems like a good idea?

I have not had mine apart, but this doesn't sound like something CAT would do at the factory. If they intended for that edge to be sealed they would have continued the weld into that spot. Th other issues is if the RTV does come loose, where is it going to go? I think the answer is nowhere it will do anything any good.

 

[Strecker25]

I guess the question is was there RTV in these from the factory and is this the recommended solution from CAT? Or is this something that is done because there was a couple pictures floating around the internet, and it seems like a good idea?

I have not had mine apart, but this doesn't sound like something CAT would do at the factory. If they intended for that edge to be sealed they would have continued the weld into that spot. Th other issues is if the RTV does come loose, where is it going to go? I think the answer is nowhere it will do anything any good.

i thought the same thing but based on the history with our boat and knowing the previous owners (along with the service history and perfect paint on the bolts) I’m fairly certain ours had never been removed since new

interesting question to as CAT though

 

[Njlarry]

Good points. The paint on our bolts was perfect too. However the inside looked so clean I have to think it was cleaned sometime before.
Thanks for the pics as my welds look the same and there was no sealant at all when we removed it.

 

[Njlarry]

Was finally able to post pic. Here it is. Aftercooler just after removing with 800 hrs. No trace of a sealant. Weld is visible but no sign of any sealant.

 

[Njlarry]

The other half.

 

[dtfeld]

Welds look solid. I'm not sure that RTV adds much if anything, except a foreign material to be injested if it starts to fail.