[Archived]

Transynd intervals for normal commercial duty are 300,000 miles/48 months/6,000 hours; for severe duty it is 150,000 miles/48 months/6,000 hours.

The transmission oil sees much less use in our coach. We do less than 10,000 miles a year. I plan on changing it every 5 years.

Similarly for extended life coolant. I check coolant chemistry with test strips twice a year. As long as pH and nitrates are within range, there is no need to change coolant. The chemicals can be adjusted via SCA filters. I also plan on changing at 5 year intervals but probably would not need to as long as chemistry is fine.

Gerald

[Archived]

You CANNOT add SCA’s to extended life coolant. Extended life coolant is typically a 6 year change interval, but if it has had conventional coolant added or an SCA / conditioner used in the system it reverts to a 2 year life.

Others may disagree but the consequences of worn out coolant being used in our engines can be very expensive so that is one change interval I do not deviate from. Even with adherance to the prescibed change interval on my 8V92 coach the cooling system was adversely affected with silicone dropout necessitating a recored radiator.

[Ron]

Jon,

I use PEAK Fleetcharge Heavy Duty SCA precharged coolant. It is NOT one of the “long-life” coolants (containing carboxylic acid inhibitors). PEAK calls it “Fill-for-life”. It is fully compatible with standard SCAs.

Here is from their Q&A website:

Q:What is meant by the term Fill-For-Life technology?

A: The Fill-for-Life alternative provides for easy, low cost monitoring of the coolant inhibitor and freeze protection levels. Fill-For-Life is an extended service maintenance program developed by FLEET CHARGE® and Penray researchers. It is very simple. Users simply install a Penray Need-Release filter on an engine coolant system (up to 30 gallons). Every 18 months the filter is replaced. This practice eliminates scheduled coolant changes.

https://www.peakhd.com/product-lines/fleet-charge/faq/

I agree that mixing coolants is a bad idea. I flushed the system twice before I switched to FLEET Charge.

Gerald

[Archived]

That is a good alternative to 2 year or 6 year OAT technology coolants. Since it meets the DD 93K217 specification it is acceptable in our Series 60 engines.