RMI-25 Cooling System Treatment

From $35.00 incl. GST

RMI-25 provides superior cooling to glycol based, and waterless coolants…and, at a much lower cost! If you don’t need antifreeze, you don’t need glycol.
  • Engines run cooler
  • Outstanding cleaning ability
  • Lubricates water pump seals and heater valves
  • Guards against corrosion and electrolysis
  • Can be used with water alone or conventional coolants
  • Non-toxic and biodegradable
  • Doubles hose life
  • Low cost concentrated formula


Engine overheating?

RMI-25 will cool it by 7C…or more!

Even a thin layer of mineral scale through the radiator and engine water jackets is a major barrier to efficient cooling! RMI-25 added to the coolant quickly dissolves mineral scale and sediment from conventional type coolants.

Water provides more efficient cooling that the common gylcol type coolants, which are not necessary under typical Australian conditions. (Waterless coolants are generally pure glycol, and your engine will run hotter!!)

RMI-25 cleans and cools

Toyota Landcruiser Fleet: With over 100 Landcruisers in this WA mining fleet, an average 25 water pumps failed a year due to the hard water used. The seal lips go first, then the bearings. The first year on RMI-25 Cooling system treatment saw 1 failure. The second year no water pumps failed. Expect longer pump and hose life with RMI-25.

Want radiator hoses that last twice as long? A coolant that lubricates water pump seals? Want an end to aluminium corrosion under hoses? Want to eliminate stray current that can corrode radiators in under 12 months? RMI-25 is THE real life FIX! The RMI-25 is a concentrated additive designed to Clean, Lubricate and Protect your radiator.

Why spend money on replacing expensive glycol when RMI-25 will clean and cool your entire cooling system while you drive.  RMI-25 makes engines run cooler, prolonging engine life.

One Easy Application – Just pour some in your radiator and drive away.

  • Non-Toxic System Cleaner
  • Corrosion Protection
  • Inhibits electrolysis
  • Avoids Water Pump failures
  • Doubles Hose Life
  • Prevents cavitation & pitting
  • Contains Fluorescent leak detector
  • Cost effective glycol alternative

If you don’t need antifreeze, you could just use water and RMI-25. And if you love remote travel your cooling system provides an additional source of emergency drinking water. (Just make sure all traces of glycol have been thoroughly washed out first! Can’t guarantee that it tastes nice, but it’s not toxic!)

SAVINGS HISTORY: Has prevented water pump failures ($300 to $4000), and avoided engine loss caused by failed cooling systems in thousands of applications, saving rebuilds from $4000 to $200,000 plus.


Most products cannot prevent scale build up on cooling systems surfaces, which therefore require caustic or acid bathing.

RMI-25 breaks down solids to molecular size holding them in suspension, which discolours the cooling water to darkish brown. This colour change can occur within 6-10 hours of operation.
When this happens, simply drain system, back flush and re-dose until cooling water retains yellow-green colour. At this point, system is perfectly clean and will remain so if dosed accordingly.

RMI-25 Cooling System treatment can be added to all glycol based coolants or just used with water. Where anti-freeze is required, it should also be added. It is both a cleaner/de-scaler of the entire cooling system, as well as providing complete protection to all types of system materials.

RMI-25 cleans (and keeps clean) cooling system and at the same time prevents corrosion, cavitation erosion and cylinder pitting. It lubricates water pump seals, heater control valves, drain plugs and virtually eliminates water pump failures, while preserving hoses, O-rings and seals.

Unlike other cooling system treatments, RMI-25 is Non-Toxic and biodegradable, it is entirely safe to use in environmentally sensitive areas.

Directions for Use

Add RMI-25 directly into the radiator
250ml will treat 20L
1Ltr will treat 80L

Blocked or corroded systems will be cleaned within 15Hrs of regular driving
(excessive corrosion/blockages will float to the surface and can be removed or flushed from overflow tank)

RMI-25 replaces the need for regular coolants. 

9 reviews for RMI-25 Cooling System Treatment

  1. 5 out of 5

    AJ Campers Pantry

    Our 30 year old 80 series Landcruiser like a lot of old diesels had some issues with the heat. We had a Redarc gauge installed to monitor these coolant ups and downs. As soon as we switched to the RMI-25 product we had a drop by 10ºC in engine temperature. Thats a massive decrease and peace of mind when remote touring in the hot Aussie outback.

  2. 5 out of 5

    Aaron Taplin

    Works amazingly well – successfully cleans out neglected cooling systems with immediate results shown on the temp gauge. Also works well in our supercharged race car – keeping both engine & charge cooler temps significantly lower than before.

  3. 5 out of 5


    Bought some for my td42 nissan patrol mainly to clean the system but the added cooling benefits are great.

  4. 5 out of 5


    Bought some for my td42 nissan patrol mainly to clean the system but the added cooling benefits are great.

  5. 5 out of 5

    Terry Cogzell

    Done a great job of cleaning rust stain from my 2002 hilux cooling system after a week or two.

  6. 5 out of 5


    Great stuff.
    Have been using it in all my vehicles for many years.
    So easy to use.

  7. 5 out of 5

    Edward Cook

    Haven Cook – August 15 2023
    Had a Hino P10 come in with oil coming out of the cooling system. Checked engine and decided it was the engine oil heat exchanger in the side of the engine. We couldn’t get a replacement oil heat exchanger so we dosed the cooling system with the recommended dosage of RMI-25 and took it for a 20 minute drive. Drained the cooling system. Then dosed the cooling system again and sent the truck back to the customer. We got the new heat exchanger in 2 weeks later, but the customer couldn’t get the truck back for 4 weeks. We checked the overflow bottle and it was almost full of oil. When we removed the radiator cap there was no oil on top of the coolant. We drained the coolant and removed the heat exchanger and found no traces of oil in the water gallery and also no rust deposits. I couldn’t believe it. Good stuff.

  8. 5 out of 5

    David Wall

    Used this in 2005 TD42TI Gu Patrol.
    The factory temp gauge would sit in the upper end of the range when driving at 110kph for long periods.
    For reference i live in the NT.

    I drained the cooling system and used RMI 25 with distilled water to fill it up.
    I drove 650kms from Katherine to Boroloola today(05/12/2023) with outside temps pushing 40 odd degrees.
    Coupled with the RMI 25 and the new larger intercooler scoop, i was able to maintain 115-120kph the whole way.
    No longer having to drive to the temp gauge. The temp did creep up on a couple of hills when the cruise control was set to 120, however the needle only went up about one needles width, nothing like before where i would be required to back off.

    Great product.
    Highly recommend

  9. 5 out of 5

    Nathan Trezise

    What a great product that does as described. i have a 1955 FJ Holden, we all know they used to run warm. so i added a dose of RMI 25 to the coolant that was in it and ran it around until it discoloured as described. a drain and a back flush and refill of water and only RMI25 an the ole chap now runs the coolest it ever has. 35 degree day, arh no worries, the old grey engine still keeps it cool. I no longer have to keep an eye on the temperature. its been months now and has barely discoloured since not bad for a cast engine. Super wrapped.
    Highly recommended even in the old classics.

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