Core of heat exchanger D1-20 stuck

[Kmbarlow]

I noticed some corrosion on end cap of heat exchanger of my Volvo penta D1-20 so decided to service. I have removed both end caps with difficulty but now the core just won’t budge. I have tapped with a wooden block lightly but no good. I have removed most of corrosion near core end plate. Still won’t move. Any tips? Do I need a completely new heat exchanger? More of core tubes patent but need a clean.
Thanks Karen

[JEN-et-ROSS]

If you can get a decent grip of both ends of the core and very gently try to rotate it back and forward to try to dislodge the crud that's jamming it...
If it moves at all, then tap it gently again back and forth.  Try repeating, as it should eventually free itself....
Replacing the unit would create a big hole in your savings so best avoided...........Good luck.....Bill.

[Yngmar]

Make absolutely sure you're pushing in the right direction first! On ours (MD22) it only comes out one way

[Kmbarlow]

Hi I only have 2-3mm at front to grip it and worry I will bend the core. How tough are these things? The o ring  at the back is almost completely off but bits remain embedded. I don’t think that’s the cause though. I guess I could take off while exchanger but not sure how to do it. Thanks for your help
K

[IslandAlchemy]

When I took my heat exchanger apart a few years ago, there was some corrosion at the end caps and the stack wouldn't come out.  When I finally managed to get it out (using brut force), the heat exchanger was corroded around the stack and was deemed to be FUBAR (a medical term.  F***d up beyond all repair).

I hope this is not the case with yours, but it may be worth starting to look around to see if anyone's selling a heat exchanger assembly just in case.