My RMI-25 Experience Thread

[SZR48207]

I decided to give this stuff a try on my 2002 F150 with its less-than-optimally-maintained cooling system. During my last coolant drain/fill about 3 years ago I noticed some mild crud/scale buildup in the overflow tank, so I wouldn't be surprised if there was some cleaning needed.

This morning I suctioned out a small amount of the coolant and emptied a bottle of RMI-25 into the tank. The appearance was like if you left a yellow highliter to dissolve in some water. It contains a fluorescent dye that you can use to trace leaks with a black light, if needed.

The label indicates I need to drive for about 2 weeks to get a thorough cleaning.

I will update as time goes on. I'm hoping I will eventually see the nasty stuff floating at the top of the reservoir.

 

[SZR48207]

First check. Not much to report, and the picture doesn't show it well but there is some minor "crud" or "foam" floating at the top of the coolant reservoir now. I'm taking it as a sign of progress that some cleaning action is occurring.

Just for kicks, I bought one of those Prestone coolant checking bulbs and used it. (pic below) The needle maxed out at the highest boilover and lowest freeze numbers. Could be from the RMI-25 as it advertises that it can recharge coolant, but I should have taken a reading before putting it into the truck. Not sure how much faith to put into a $3 gauge, though.

My next check, I'll use my black light flashlight to see if it shows anything different.

 

[LeakySeals]

Confirming this...Did you put it in the expansion tank, or directly into the radiator? Depending on which one it will take more or less time to see results. Its more concentrated, works faster adding to the radiator.

 

[SteveSRT8]

^^^Very platform specific advice.

Some vehicles have active circulation in those tanks, some do not. This would mean drastically different mixing!

 

[LeakySeals]

So its best to use the radiator every time? I thought expansion tanks always circulate. Some don't?

 

[SZR48207]

I poured it into the expansion tank. My commute is about 40 minutes/15 miles from work 5 days a week so I'm thinking there is some circulation happening?

 

[bullwinkle]

Originally Posted By: LeakySeals
So its best to use the radiator every time? I thought expansion tanks always circulate. Some don't?
Tanks with a pressure cap circulate (the OP's Ford), ones without a pressure cap don't circulate much, just the expansion of warming up pushes AF into the tank, the suction of cooling pulls it back out. In winter my non-pressurized tanks don't seem to change much.

 

[SZR48207]

Almost a month later. Different camera, so the coolant looks a bit different, but there really seems to be no change.

I haven't noticed any ill effects, but I'm not really sure what to take from this product so far. I was under the impression that things were a bit dirty in this cooling system, but it could have been scale buildup ONLY in the reservoir. I was expecting to see clumps of gunk floating in there, but that is not the case.

I'm planning on doing a drain/flush/refill soon so I'll leave the RMI in until then.

If anyone can suggest ways I can test this more thoroughly, I'm open to ideas. I don't want this to come across as a "negative" review since I couldn't report great results. My vehicle could have been a bad candidate.

 

[86cutlass307]

I wanted to give a you little feedback on this, I don't have any pictures to add but I did try 2 of the 8 oz. runs as suggested on the bottle in my daughter's 2000 Saturn V6. It was a factory Dex-Cool engine, and it did semi-liquify some crud that was in there and it all eventually collected in the coolant tank which is translucent/clear. My expereience was positive, it will dislodge and for the most part liquify and keep in suspension any crud you have. I'm not a big fan of super aggressive coolant system cleaners similar to what was available in the 70's and 80's. While they are very effective on cast iron engines with copper/brass radiators, if you have a neglected cooling system you should have a new water pump in your garage ready to chenge out after using these coolant system flushes. They break up all the stuff, the calcified stuff is like rcirculating glass shards, they tear up the water pump seal and BAM, a nice leak! I learned all about the joy of an Oldsmobile V8 water pump change in high school after doing this to prepare for winter. My running buddy had a Chevey truck and his was a piece of cake.

 

[3311]

Where do you guys getting this stuff. I prefer to buy locally.

 

[86cutlass307]

You can pick RMI-25 up at amazon in an 8 oz. or 32 oz. or gallon bottles, I bought some 3-4years ago and I have been using it up. There are a few places that carry it but Amazon seems to be the cheapest. If you mean TSP, trisodium phosphate, check a farm supply store, Atwoods, Tractor Supply if you have those in your area. If you need some for a project I can send you some if you don't mind shipping.

 

[PHANI1]

Been using RMI25 for over 10 years in 3 vehicles; all high mileage eventually. Have not had a cooling system issue of any kind while using it. Add 8 oz every 15k miles; replace fluid about every 5th cycle, even though it says you don't have to.

If you don't have crud floating on the top of the fluid in your plastic tank after a few weeks, then your system was reletively clean to start with. On Ford vehicles without a radiator cap, all the fluid eventually flows through the plastic tank.

 

[kyoo]

Novice here, ready to add 4oz or so to each of my cars in sig:

So, we definitely do want to add it to the radiator directly? And if so, would there be bubbling/need to burp the system afterwards? Sorry for the novice questions

 

[PHANI1]

If you have radiator cap, add it there. Normally, you have to remove a few ozs. of fluid to make room for the RMI-25; add what you remove back into the overflow/expansion tank. (do this with cold radiator)

If no rad. cap, ad to expansion tank. With pressurized expansion tank, product will mix into the entire system within a few heat/cool cycles.

 

[DBMaster]

My Mazda3 has a pressurized recovery tank. I have been adding 4oz every 15,000 miles. Since no system is hermetically sealed I have not had to remove any coolant to do so. Also, since I started using the product early in the car's life there has been nothing for it to remove. I am interested in the value of the additive and extending the life of the coolant.

 

[PHANI1]

I am interested in the value of the additive and extending the life of the coolant.

I don't have any hard evidence which says how many years you can go with just the RMI recharge cycle every 15k miles; so, I do a complete fluid exchange (plus dose of RMI-25) every fifth dose or so - chemical cleaning flush certainly will not be needed.

In newer vehicles, when used every 15k miles, I would expect all system components, including hoses and water pumps/seals to last much longer. If it extends the life of the heater core, that alone is more that worth it.

It also acts as a "water wetter".

All coolant system components, including water pumps and hoses, in the vehicles in my sig. are/were original.