JD 455 collant testing question

[gsxr1100]

Okay guys--I need some help with this one. I need to test the SCA level in my collant. What range does JD recommend?

(ie. I have a Ford Powerstroke and Ford recommends the range go from 1.2 to 3.0 max SCA units). Is it the same range for all diesels?

I just want to make sure because i can't afford a collant problem (liner pitting).

"Were going to need a bigger boat" JAWS
Got the tractor, need bigger yard to play in!

 

[TomG]

I can't help with JD specifics. However, I do know that some engines are more prone to pitting from coolant cavitation--especially heavier engines. I believe that typical recommendations are to change the coolant every two years and use a low silicone coolant. However, I've heard that anti-cavitation additives last more like months than years, and that it's a good idea to use an additive in an engine that's prone to pitting.

My dealer said he had a log skider in this summer where the coolant had never been changed, and the engine was ruined.

 

[cowboydoc]

Tom,
You're exactly right on the cavitation. Ford had a big problem with this. When they had navistar design the engine navistar put on an inline system that would constantly add DCA4, cavitation inhibitant, to the system. Well ford in all their wisdom took this off and never told anyone. They had alot of diesel motors cavitate and never did anything about it until 1999. Then they came out with a bulletin that said that you must continually check your coolant to avoid cavitation. They wouldn't do anything about the engines that had already cavitated unless they were still under warranty. So much for quality being job 1.
Richard

 

[cowboydoc]

Burnickas,
International makes a test strip kit that you can use to test your SCA level. Just dip the strip in the coolant and compare the color shades to the chart on the back of the kit. Then you just add DCA4 to bring it up to par. I'm sure someone else has them I've just always gotten them from the international dealer. International told me that it was the same for all diesels.

Richard

 

[dmccarty]

Ahhh, can you guys explain some of this stuff? I have never heard of cavitation in regards to cooling systems. What is SCA? Is this a problem in all engines or just diesels?

Thanks.....
Dan McCarty

 

[cowboydoc]

Dan,
All diesels are prone to cavitation. Cavitation is where vibration in the cylinder walls causes the cylinder linings to eat themselves away. An inhibitor to this called SCA4 lines the walls and protects them from this cavitation. That is why with diesels you either have a replaceable rechargeable filter or you use a precharged antifreeze.

 

[TomG]

I'll take a shot at the physics of it--or at least how I understand them. Unlike gas engines, diesels produce particularly high-energy sound waves at particular frequencies. The way sound works, these frequencies may concentrate and be sustained in particular areas of an engine. Acoustic principals of resonance and standing waves may apply.

Sound waves are patterns of increased and decreased pressure in a transmission media (the coolant in this case) and the boiling temperature of a liquid is related to the pressure it's under. With an already hot coolant, the effect of these high-energy pressure waves is to create localized areas where the coolant is above the boiling temperature.

The effect creates bubbles, or cavitation, in low-pressure areas. The bubbles travel and disappear when they enter higher pressure or lower temperature areas. Metal on the inside surfaces of water jackets erodes in areas of cavitation. I believe that use of high-silicone coolants increases the erosion.

That's my shot at it. Operating my tractor is fun, but I also get hooked on this sort of stuff. If I haven't got it quite right, I imagine somebody will tell me.

 

[Boots]

OK Guys, I looked in my manual for my 50hp JD tractor that was made around 1979, and there was no mention of this. It just tells me to use antifreeze/rust inhibitor (50%), and soft water. Is this a recent discovery? Any down sides to using this additive?

Boots

 

[cowboydoc]

Boots,
According to everyone that I have talked to from head mechanics at the ford garage to big truck mechanics to heavy machinery diesel mechanics they have all said the same thing. Cavitation can happen in any diesel. Trucks usually have a replaceable filter and some tractors have this as well as the big equipment. From what I've been told cavitation has happened to everything from lawnmower diesels that are liquid cooled to $500,000 dozers. Doesn't happen to all of them but some. To combat this you can go one of two routes. Either replace your current coolant with an SCA4 precharged coolant and change according to their recommendations or run your regular coolant add DCA4 according to the test strips every 6 months. Alot of the mechanics I talked to said alot of mechanics don't even diagnose it when it is a sleeve or cylinder problem. The fix is either new sleeves or a new block. I have it in all of my rigs now. It's pretty cheap insurance to me. I can buy the Fleetguard anitfreeze at Farm and Fleet for $6 a gallon that is precharged. You can go 100,000 miles, 750 hours, or three years. I can change all of my fluids every two years anyway so I really wasn't out anymore money anyway and like I said it's cheap insurance.
Richard

 

[Boots]

Richard,
Thanks for the info, I just called and found a local supplier with the additive, and test strips. I think I'll head down there today and get some of this since I just changed my antifreeze to Prestone. My only trouble is that this engine has likely ran without this for the last 20 years!

Great Information.

Boots.