Heat Exchanger End Cap fitment - (Caterpillar)

[Fire99]

Hi all,

I'm just in the process of fitting a replacement end cap (plastic) to my Caterpillar heat exchanger. It has two rubber seals. Do you tend to use silicone grease on this or some other marine wonder?

Any thoughts appreciated..

Nick

 

[Nito]

I personally would use a smear of silicone grease.

The side with two seals, I believe one is for the bundle, which means you may need to drain your engine coolant for that I think?

I’ll shortly be replacing one on each of my engines, they have lost continuity with the anodes.

cheers
Nito

 

[Fire99]

Hi Nito.. Yeah it was the end with two seals that meant a coolant change.. The old cap was found to be damaged and had had a 'temporary' repair done at some point.

I went with the silicone grease. It was still a tough fit. Lots of wrestling but it got on in the end...

Hope yours get changed without any problems...

 

[Nito]

Thanks for the heads up. I’ll be doing them myself. If just changing the cap, I’m guessing that can be done without removing the bundle and necessitating the coolant change?? Even so, I have new coolant, the later recommended thermostats, and all new hoses to go on and already have both of the seals ready to do it.

I believe I read elsewhere that you have the 3126’s. Are yours the MUI (mechanical injector) 8NM 420hp ones?

cheers
Nito

 

[Fire99]

Thanks for the heads up. I’ll be doing them myself. If just changing the cap, I’m guessing that can be done without removing the bundle and necessitating the coolant change?? Even so, I have new coolant, the later recommended thermostats, and all new hoses to go on and already have both of the seals ready to do it.

I believe I read elsewhere that you have the 3126’s. Are yours the MUI (mechanical injector) 8NM 420hp ones?

cheers
Nito

Yes the bundle can stay in situ but unfortunately your coolant will come flooding out when you remove the end-cap (how do I know that? haha) so do drain the coolant down first if you don't want a coolant flood. It is a very tight fit getting the cap back on (I guess it needs to be to keep seawater and coolant separate) and not wanting to teach you to suck eggs, don't over-torque the cap, even the anode. It's only plastic and my old cap had a crack that looked from over-tightening.

My engines are the later 3126B's with the HEUI oil activated injectors and the slightly hard to read Cat digital displays..