Cooling system flush.

[MuddFlapp]

I’m going to flush and change the coolant in my ‘07’ 5.9. Use to I would cut into the heater hose add a T and attach a water hose, disconnect the top rad. Hose and flush it, then run out as much water as possible then refill with the proper coolant.
Instead of cutting the heater hose on my truck I think I should disconnect the hose, connect a tee and 6” of hose then reconnect to the head fitting,
My question is how to get all the water out of the block. Can I blow air through the system? Or maybe turn over the engine without letting it start?

If I drain the radiator will there be enough room to add the correct amount of coolant to get a 50/50 mix?

Thanks

 

[p-Bar]

Just pull the bottom hose . Don't touch the petcock on the radiator

 

[Bob4x4]

The best way is to use a modern flush machine. They will suck out the old and replace with new without inducing air. I don't even do my own at home anymore. If you find the cost savings worth it to you you might consider pulling the t stat out while flushing. Be very careful if you attempt to use air pressure. The heater core is major work and the radiator is pricey

 

[p-Bar]

Agree with Bob . I took it to have it done didn't need to deal with getting rid of the old stuff also.

 

[cerberusiam]

You cannot get all the water out of the block, aboout 1.5 gallons will always be in the bottom where it cannot be drained. When you start the refill add 1 gallon striaght anti freeze then 50-50 mix from there and top the reservoir with the 50-50 mix also.

You have 2 choices of what to do here, a flush and fill OR coolant exchange. A flush will entail multiple drain and fill with preferrably distilled water until your drain water is looking clear. How clear you want it is a personal choice. I went thru 20 gallons of distilled water flushing until I thought it looked good.

An exchange can easily be done with a machine and you don't have to dispose of the old coolant. Not sure if there is a flush machine avialable thta will do as good a job as fill, warm, and drain until it looks clean. Probably is but no one I talk to has any idea how to do it or even if it is needed. The gasser market dominates most of the offerings.

 

[MuddFlapp]

[QUOTE=. I went thru 20 gallons of distilled water flushing until I thought it looked good.

What if I flush with tap water, then flush with say 5 gal. of distilled water, then started with the Coolant.

 

[cerberusiam]

It is better than using straight tap water but not optimal because you cannot completely drain the block. You would have to flush at least twice with distilled water to dilute it at about 5 gallons per fill. Might as well use all distilled water at that point.

The cooling systems on these diesle are finicky, tap water contains soilds and generally chemicals that do not react well to the coolant and environment causing scale buildup. That in turn plugs the radiator, messes up the water pump and thermostat.

 

[Bob4x4]

I have yet to see a Ctd 94 or newer with a plugged radiator. Many leakers at the seals though

 

[Bob4x4]

I have yet to see a Ctd 94 or newer with a plugged radiator. Many leakers at the seals though

 

[MuddFlapp]

I have yet to see a Ctd 94 or newer with a plugged radiator. Many leakers at the seals though

What's your're point?

 

[Bob4x4]

What's your're point?

These trucks are not prone to contaminated cooling systems,normal maint,is all that is required nothing fancy just follow the owners manual.It does not need to run 20 gallons through it

 

[Tractorat]

Man, that sounds like a lot of work.
I just take mine down to my local trusted shop and go get a cup of coffee. When I get back, the coolant had magically been serviced. And, I dont have to worry about getting a ticket for draining engine coolant into the drainage system.

 

[cerberusiam]

These trucks are not prone to contaminated cooling systems,normal maint,is all that is required nothing fancy just follow the owners manual.It does not need to run 20 gallons through it

Prone to contamination or not, that is NOT what the recommendations from Cummins or the coolant manufacturer say, nor does it address the reasons for doing so. The B series engine rec's from Cummins are 200k, 2 years, 6000 hours, which ever comes first. The HOAT coolant is generally 5 years and 100k whichever comes first. The standard procedure for flushing coolant from ANY engine has been using distilled water, fill-warm-drain until the drain is clean. How many gallons of flush is dependent on how deteriorated the coolant quality is and the amount of crud coming out, regardless of anything else. Using tap water is a no-no due to the chlorine found in many water systems that kills the coolant performance.

The B series engine do not generally come with coolant filters so flushing is a highly recommended activity on a regular basis to keep the contamination and build up from causing issues. The OM simply says replace after a specified time, assuming this will be done by a qualified shop\person\process. The process to replace has to include a flush due to the design of the block, flushing must be done with neutral fluid or it interferes with coolant performance. It only makes sense to do it right since it is done so infrequently.....or not depending on ones particular mindset.

The process I described has been used successfully for more years than most of us have been drawing a breath, deviate at your own risk.

 

[NIsaacs]

You cannot get all the water out of the block, aboout 1.5 gallons will always be in the bottom where it cannot be drained.


This drives me crazy:-laf I just can't understand how this is possible, other than the small amount that can't drain due to the rear being slightly lower than the front of the block. Why would Cummins not install a block drain if this were the case? The coolant flow chart shows it does drain. The repair manual says the engine cooling system holds 11 quarts, if 6 quarts were left in the block that means only 5 quarts drains, that's only about the head capacity.

Nick

 

[cerberusiam]

The repair manual says the engine cooling system holds 11 quarts, if 6 quarts were left in the block that means only 5 quarts drains, that's only about the head capacity.
Nick

I doubt many are tearing the engine down to drain the coolant. The internal block is not smooth channnels, webbing and block structure along with engine poistion determine that it doesn't all drain with typical procedures.

The cooling system capacity on a 5.9 is 24 quarts not 11, you are forgetting the radiator and hoses.

 

[NIsaacs]

The cooling system capacity on a 5.9 is 24 quarts not 11, you are forgetting the radiator and hoses.

I was talking engine cooling system capacity, not vehicle cooling system. I will say that on a cross flow radiator, if you don't tilt the vehicle or use compressed air from side to side they will retain a bunch of coolant. 1.5 gallons will not be retained in the engine block, gravity will not allow it....

Nick

 

[cerberusiam]

Apples to oranges, the title of the thread and all we are talking about is complete cooling system not just engine system. Gravity means nothing when the drain path is obstructed and the drain point is higher than the lowest level in the block and the block is tilted.

Easy way to validate, go drain the system using the petcock or lower rad hose, measure what you get out without extraordinary measures. Roughly 6 quarts of the 24 total does NOT drain out.

 

[NIsaacs]

Roughly 6 quarts of the 24 total does NOT drain out.

I agree with this statement. I don't agree that the 6 quarts is left in the block. The heater core will not drain, the block is tilted in the vehicle, it will retain a quart or 2, the rest will stay in the cross flow radiator. Air will get it all out. I also understand the thread is about the complete cooling system. My comments on the block capacity (part of the vehicle cooling system) is to point out what it's capacity is, that 6 quarts retained of an 11 quart system would only be draining the head. Did you look at the flow charts? The inlet is the lowest point.

Nick

 

[MuddFlapp]

The cooling system capacity on a 5.9 is 24 quarts not 11, you are forgetting the radiator and hoses.

I assume this means just the block. My OM say 29.5 qts. total. At any rate I have my distilled water (20 gal) lined up and will do my own flush and refill this afternoon. This is most likely the last truck I will buy so I feel I should do everything I can to preserve it.

Thanks for all the input and advise. As always TDR is a great soundboard for maintenance and repairs on my CTD.

 

[cerberusiam]

I assume this means just the block. My OM say 29.5 qts. total.

Sorry, fat fingered it. Should have read 28 qts on my 05. I bought 4 gallons of concentrate and had a little over 1/2 gallon left after fill. Always used 24 qts on the 12V's for a number. Fingers got confused and didn't listen to brain.