Will coolant filter filter out stop leak?

[porcupine73]

Hi all, I have some Baldwin additive free coolant filters and was about to install one in bypass on my '00 subaru 2.5L, but was wondering if it would filter out the stop leak/coolant additive?

This engine has a TSB out for external head gasket leaks and subaru wants you to put in this 'coolant additive' (stop leak) which I believe is rebadged Holts Radweld.

I don't know what's in this stuff but it looks a lot like Bars Leaks and am wondering if maybe I shouldn't install the coolant filter if it may just filter it out.

 

[porcupine73]

 

[unDummy]

I'd wager that the filter will remove some of it.
Test the theory. Install the filter. Run it for several months and cut it open. See if the stopleak gathered in the filter.

 

[randozr2]

That stopleak has particles which by definition, will stop-the-leak by clogging it up. The filter, by definition also, will filter out any particles that it catches (always depends on how big they are of course). Those particles will clog whatever very small passages that they go through- hopefully the leaks first, but also any small coolant passages, and of course any filter that is purposefully installed to catch them....
it is a stopgap measure usually, always best to actually fix the problem.

 

[porcupine73]

Thanks for the info unDummy and randozr2. I decided not to install the filter for the time being. I was planning to put it in series with the flow through the throttle body. I have a feeling the filter would just pull out the stop leak particles. The only way I could probably not use the stop leak is if I pulled the engine and replaced the HG's with updated ones. Or I could just not run the stop leak and add it if I notice the external leaks at all, but I probably wouldn't check all that often anyway.