Qsb 5.9 aftercooler service

[Mike Mason]

The one unknown when we bought our boat was when the last time the aftercoolers were serviced and to who’s protocol. I consider these the heartbeat of the motors and wanted to know what exactly we had.

I spent a few weeks doing some basic maintenance and today I broke down and pulled the starboard aftercooler. Getting it off is an easy 30 minute project.

I then put it on the dock and proceeded to loosen the top and bottom caps. As soon as I got the first bolt out, I noticed the green grease Tony preaches on this site. I was feeling good to say the least.

I pulled both caps and was covered in grease. Ok by me. Someone had taken the time to do this the correct way previously.

The zincs are still in excellent shape as the water drained is all fresh from our diligent flushing of the motors after every use.

I brought the aftercooler home, used block of wood and very little persuasion from a small 3lb hammer and the bundle slid out.

Ordered the o rings and a gasket from Seaboard which will be here tomorrow.

Got the brake cleaner out and started spraying.

I was surprised there is absolutely zero pitting and corrosion on the mating surfaces. I cleaned them up with emory cloth and now I wait for the reassembly
With plenty of grease.

Here are the pics. If I missed anything, let me know.

Mike

Topic

[Mike Mason]

Ran her up today. All good.

Port side next week.

[Rob Schepis]

That works. Thanks for the post and pics Mike.

[Mike Mason]

UPDATE

Got my o rings today. Mine used the thinner of the two sets received. Thanks Seaboard.

Went back together as planned. Lots of lube!!!

Tightened everything up and pressure testing to 15psi. Soap tested and no leaks so far.

Should be back on the engine later today.

Thanks Tony and team for leading the way!!!

[Rob Schepis]

Good deal Mike, do keep us updated with progress and pics.

[Mike Mason]

Made up some stuff today to bench test.

[Stephen Oliver]

If you are bench servicing – why would you test that way – if it leaks – you have to strip down again. The parts are cheap and easy to put together for a test rig as long as you have a compressor? I test both air and water side for 24 hours separately.

Steve

[Mike Mason]

Tony and team…

Can I pressure test on engine in neutral at 2000 rpm with air side open? Check for leaks that way?

[Tony Athens]

Someone was listening & the results of that are what you just experienced……………………….

All is good!

Tony

[Author]

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