Wednesday, November 28, 2007

Diesel Coolant-What Color Should You Use?

Diesel Coolant has changed over the years and the most apparent difference is the various diesel coolant colors available on the market, there's green, red, purple, blue, orange etc. So what do all these colors signify?

In my part of the country the authority on coolant is a company called Recochem who manufacturers coolant, this is what they have to say.

Both packaged and bulk heavy duty diesel engine coolants will be transitioned from green to purple by June 1, 2007. The change of color will not affect the performance of the coolant. Green and purple coolants can be mixed and will perform to specs.

Four Types Of Diesel Coolant Are Described below:

  • Green coolant [Ethylene Glycol] needs to be pre-charged with DCA4 & tested regularily with proper test strips provided by Fleetguard.
  • Purple & Pink [Ethylene Glycol] coolant is a conventional heavy duty fluid that is already precharged to specs. no treatment is required.
  • Blue colored coolant is a Propylene Glycol that is the equivalent of the purple and pink mixture.
  • Red has Organic Acid Technology and meets one or more of the OEM [original equipment manufacturer] specs. for International, Caterpillar, Detroit and Mack diesel engines.

Labeling close to the coolant fill tank is advisable so mixing doesn't occur with the acception of the green and purple diesel coolant.


Bob said...

hey john my name is Bob im a diesel mechanic also just wonderin if youve ver heard of final charge? its the red coolant that cat is using now so they told me anyway. just wanted to let ya know they make a converter it comes in gallon jugs and it makes any color coolant compatable with regular final charge premix coolant talk to ya later nad your blog is cool by the way good work

Anonymous said...

john...saw your site and wanted to inquire if you have access or contacts to purchase good used buses. they are in need in the country of honduras. i am considering buying one as an investment to send there to use for the transportation need. profits will be used to fund free housing projects. can you help me? contact steve at

John Whelan said...

I recommend & promote Ebay Motors for used buses because of the wide variety and security involved. We have used buses in our fleet that are auctioned off locally or sold privately but only a few at a time.
Good Luck with your project!

Anonymous said...

hi, today I followed my son school bus on a field trip..I noticed a hose become loose on the bottom left side and green fluid coming out...alot, then about 5 minutes later I saw a lot of smoke coming out of the pipe..what is all that and is that normal..Should i report it to the school..

John Whelan said...

That sounds a lot like an engine coolant leak from a radiator hose. I am certain the operator would have noticed this especially since the engine would eventually overheat. It's too late now but at the time it would have been a good move on your part to advise the school or bus garage.
Good Eye!

Anonymous said...

I did contact the bus garage by cell and they told me that they had told the bus driver to pull into the bus garage so they could change busses, but when she pulled into the bus garage, they didnt even look at the bus and she then was about to pull out and keep driving, but i got onto the bus and took my son off. Is there a website where i can download some info about this stuff so when i go to the school and the school district, to file a formal complain.

Anonymous said...

Also, when i got on the bus to remove my kid, she laughed in my face and said that the green stuff was just an was all normal. Well as a mom, and not a bus mechanic I would not know what was normal so of course I freaked out...and iam still pissed. I apprecaite any info you can give me.

John Whelan said...

If it's the radiator coolant overflow and the coolant is getting on anything hot on the engine, that will create smoke. There is no worries if that is the case, the rad might have been overfilled.
As far as making a complaint you could phone the maintenance supervisor and tell him your story. Bus drivers generally don't have an attitude with the public since it's there job as a professional driver to deal with situations with an open mind.
Hope This Helps.

Dennis said...

You cannot really go by the color of the coolant. There is NO STANDARD for colors. You need to check the Safety data sheet for antifreeze type and use an equivalent type to refill coolant systems on diesels now

Diesel Mechanic Jobs said...

The speed at which new technology engines has been introduced make the mechanics life more tough and hard as it was.