View Full Version : RMI-25 as replacement for hand picking out rust

12-31-2006, 09:39 PM
RMI-25 is heavily promoted as a "put in the coolant and let it work" substitute to pulling out the Freeze Plugs and picking out the heavy rust deposit. Any experience?

Terry, North Texas
1963 Avanti R2, 63SR1065
(in stage 1 resto "Project A")
1985 Kubota L2202(Diesel)
2000 VW Jetta GLS
1999 Toyota rice burner

12-31-2006, 10:02 PM
Well Terry, I never heard of it, so not sure how well it would desolve loose rust particles. However that is not what kills our Stude. radiators and causes hot spots as much as all the non-magnetic crud, mud, sand from the block casting, casting wire and just trash. No way that stuff is going to go away without complete flushing with the Thermostat and core plugs removed![:0]

Studebakers Northwest
Ferndale, WA

12-31-2006, 10:12 PM
I have not heard of it ether, but a lot of crud is behind those plugs, and sometimes they actually start to leak. Really dirty, messy job, but it seems to be required every 40 years.


01-01-2007, 06:27 AM
If you really want clean internals in your engine block, next time you pull the engine remove all loose items and block all coolant exits bar one. Then pour in brickies acid (hydrochloric acid) and let it work. After a couple of hours pour it out and your block will be super clean inside (it actually looks like fresh from the foundry). Mind you, don't let the acid touch aluminum. It reacts rather vigorously.