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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: white-eagle on May 06, 2010, 08:31:58 PM

Title: coolant flush instructions
Post by: white-eagle on May 06, 2010, 08:31:58 PM
Williams wants $300 to flush and change my AF.  i hope i can do it myself.  But there are no instructions in my manual, other than do it once a year.  i don't know when it was changed, but not in the 5 years i've had it.

By the way, williams sold me unmixed AF, the real DD red stuff, $90 for 8 gal.  cheaper than anyone else i called.  napa was $18/gal.

so do i empty it out after heating it up a little, then fill it up with water, run it, then drain.  do i run it while i'm filling or try to make sure it's full before i start up.  i'm assuming the first 2 or 3 refills will still have some green stuff in it, and i want all of it out before i fill with the red stuff?

and i plan to open the heat lever.

anything i'm missing?

Title: Re: coolant flush instructions
Post by: JohnEd on May 06, 2010, 09:17:02 PM
I recommend you put in some washing soda after you dump the antifreeze.  ALWAYS run that puppy till it is HOT before you drain.  After using the soda you will have to do the heat and rinse 3 or four times till you have all the gunk out.  On the first drain after adding the soda put your fingers in the draining water  and the stuff should have a slippery feel to it.  Keep doing the heat and flush til you don't get and slippery feel and then you are done and can drain for the AF fill.  Really important that you remember to keep the front heater on.  Also, there is a rad drain but you need to open the BLOCK drain plugs for both banks in a V config.  If you forget either of those then you will have to drain and fill and heat maybe 15 times or more to get all the soda out so make sure you drain it all every time.  Big pain but big cooling dividends.

A friend used to run the analysis lab for Cat, years ago.  The owner of that concern had all the chemistry down.  People analyzed their coolant to detect problems but they also used the info to add chems that "rejuvenated" all the additives.  He also made the chems but don't forget he was working for Cat so he was especially straight.  If my coolant passed one of these tests I don't think I would change my coolant and if I needed chems I would add those.  Cheap?  Yes!  Green? There is always that angle.  After a couple years I would drain and flush with soda if I had even the glimmer of a over heating problem or saw some change.

The payoff for not getting all of the soda, or any flush, for that matter, out is that your water pomp seal wi;ll fail and a coolant test will show the coolant contaminated.  Getting it right isn't all that tough.

After replacing 5 or 6 water pumps I finally figured out the problem.  Slow learner, I guess.  But I have now arrived.



Title: Re: coolant flush instructions
Post by: buswarrior on May 06, 2010, 09:30:10 PM
There is a two part cooling system flush available from your DD dealer.

The first, an acid sort of stuff, the second, the neutralizer. Directions on the containers.

Good advice not on the container, use hot water to mix up the parts prior to pouring them in. Better dissolving.

Usual personal protective wear, mono goggles and rubber gloves. Don't want any splashes in the eyes!

You need an old drum or whatever big enough to put the volume of acid drainage in, and then drain the neutralizer and put it in together to neutralize it all.

Best not to be rinsing this stuff into the ground water without neutralizing it.

For the rad, lots of fresh water rinse, drain, and distilled water with your fresh antifreeze.

A little pricey, but the neutralizer part removes the worry of the cure being worse than the disease, if you know what I mean!

happy coaching!

Title: Re: coolant flush instructions
Post by: JohnEd on May 06, 2010, 09:45:33 PM
All of my failed water pumps occurred AFTER using that 2 part flush.  Don't get me wrong, it is good stuff and effective.  The rinse till no more slippery is the KEY.  They lie when they say you can do the flush and neutralize it in a single rinse.  Soda is cheaper and you don't have to sweat the ground water.  To each his own and may the best man get the worm.


Title: Re: coolant flush instructions
Post by: HighTechRedneck on May 06, 2010, 10:54:40 PM
One thing for sure - don't run that engine while filling the coolant.  Only run it after filling back up.

I don't know how accessible your radiator hoses are, but if it were me I would disconnect at least the bottom one and back flush some water into the radiator and then let it drain back out.  I did that on mine while we were down there at Jack's when you guys were helping me with that water pump.  A pretty fair amount junk came out the first couple cycles of that.

Title: Re: coolant flush instructions
Post by: JohnEd on May 07, 2010, 08:40:14 AM

The Ds I worked on were hell to get warmed up enough to open the thermostat.  We vjamed all sorts of paper into te rad to stop water flow.  Given that the D has a wide open intake the incoming air, at idle, cools the engine. Remember the Cadillac that could run home at reduced speed, 30 mph, without coolant?  They had the computer skip injections and flow air thru the thing and it would live.  Armed with that logic I started the D up as soon as I started to fill it to expedite the "journey" to 180 degrees.  It still took 20 min. plus for each of four rinses and that didn't include the drain and hose removals.  It  took some time to do right,

I also opened the line that feeds the front heating system to get the last drop out.  Back flushing the rad is a superb idea.  I would add that removing the top hose as well will allow you to disgorge the chunks from topside rather than hope they will pass thru the core.  Some certainly will not and others will get caught in the core  but it is better than not doing it at all.  You need that fitting with the air connection.  They make a tool that connects to the rad hose fitting and it has two input ports.. one for the water hose that will feed the rad and another for a air line.  After filling the air is opened and it blows the water out rapidly and pushes out the junk.  I have done this many times and had the garage floor littered with chunks of stuff the size of a dime on down to course sand.  If I get that kind of crud out I pull the rad and have a shop boil and rod it.  And, I might add, I have sealed off rods that had perforated and had the rad holdup fine for years afterward and that was at 13 PSI, not the reduced PSI of most Ds.

Hope you aren't put off by my taking a little issue with your process.  Really only amplifying your process.

Be nice, ;D


Title: Re: coolant flush instructions
Post by: HighTechRedneck on May 07, 2010, 08:50:22 AM
I guess I "might" be able to see that on a dry liner engine (although I still can't find the justification in my priorities to risk it), but if it is a 92 series with its wet liners, I am pretty sure firing it up without water in the jackets would ruin the liners before you got another gallon of water in the system.

Cheaper alternative to the risk if time is that critical - take out the thermostats during the flushing phase.

P.S.  Not put off at all John.  Good debate, but just want to emphasize the risk of taking shortcuts when engine rebuilds or swaps are so expensive. 

Title: Re: coolant flush instructions
Post by: JohnEd on May 07, 2010, 08:59:13 AM

I really can't debate it.  Was really looking for info.  Thanks.  I only did this to Cummins and maybe we got lucky.  Sure cooled better afterward and passed the coolant test but his original problem was passing ex int the coolant at the turbo.  Wasn't hard to improve things after that.

Gotta call you on removing the thermostat to quicken heating....not true.


Title: Re: coolant flush instructions
Post by: HighTechRedneck on May 07, 2010, 09:09:29 AM
Not thinking of quickening heating, but rather to implement immediate flow since that is the reason to heat it up during flush - to open the thermostats and allow flow.

I draw that technique from automotive engine flushing.  We always took the thermostat out, chemically flushed it and physically back flushed the block and radiator.

Physically back flushing these big engines might be a little more of a challenge but at the least taking the thermostats out would instigate complete flow without fully heating it up.  Then after all clear, put the thermostats back in with a fresh gasket.

Added benefit:  It gives you chance to inspect/check your thermostats while at it.

Title: Re: coolant flush instructions
Post by: white-eagle on May 07, 2010, 10:25:23 AM
Backflush?  i know what that means, but how do you run water back into a radiator from a hose.  my fittings all seem huge.  Do you all go get fittings and adaptors so you can backflush?  this is starting to look like William's $280 ain't so bad after all.

and i've not even bought the flush stuff you're talkin about.  i nievely thought i could just rinse water thru 4 or 5 times, catching it the first 2 times so i cought the green stuff.

i appreciate the instructions so far.

Title: Re: coolant flush instructions
Post by: HighTechRedneck on May 07, 2010, 10:42:01 AM
That's what I mean about tougher to backflush the whole system on these.  For a simple flushing of the bottom of the radiator I wrapped a rag around the hose tightly enough times to create a bit of fit to the lower radiator outlet.  Might work for back flushing the engine too(with the thermostats out of course) by putting it into the disconnected upper radiator hose.  I'm not sure about that.

A simple water rinse is not a bad thing.  But while going to the expense of all new antifreeze, it is better to get it all cleaned out too.  I would suggest asking Williams if that price includes a chemical flush and physical back flush.

One thing a complete physical back flush helps with is to dislodge particulates from places they might accumulate.  You may recall when we were working on mine down at Jack's, one of the fittings had a coarse screen in it.  And a chemical flush will get out any mineral buildup or corrosion as well as any of the stuff that can occur if antifreeze with silicates were used at some point.  (just going on what I've heard on that last point)

Title: Re: coolant flush instructions
Post by: John316 on May 07, 2010, 12:30:21 PM
Also, one note of caution. I wouldn't recommend filling a hot engine with cool, or cooler water. When I did ours, I let it cool down pretty much all the way between rinses. Yes it took longer, but I wasn't going to let anything be stressed because of the temp changes.


God bless,


Title: Re: coolant flush instructions
Post by: white-eagle on May 07, 2010, 12:32:37 PM
New update - after finding out more about this and calling Williams back about the flush mix, we discussed some options and it turns out the actual cost for a radiator flush is $110 plus parts.

i don't know about the rest of you, but i'd rather watch someone i hope knows how to do this correctly, who has all the tools to do it correctly, and the disposal equipment to do that part right as well.  For that amount, i'll drive the 30 mi and watch them do it, make sure it flushes right (we're going from green to red) and they put it back right.

turns out they must have been charging me $180 for a-f as part of their radiator flush quote, when i only paid $90 from them for it thinking i'd do it myself.  go figure.

they said they only use the $120 flush kit when they see oil in the a-f, so it wasn't part of the quote or the plan.

again, i appreciate the hints and instructions from everyone, but this "sounds" to good to chance doing it myself this time.

Title: Re: coolant flush instructions
Post by: JohnEd on May 07, 2010, 04:36:02 PM
I would take that deal myself.  My principle heart burn is they don't "rinse" the system enough times and it costs them little to do that.  A friend with a Cummins in a S&S blew a turbo and got exhaust in the coolant.,  He WATCHED them drain the coolant and ad new coolant after they R&R that cracked turbo......no question.  3 months later he had his coolant analyzed and he had exhaust contamination.   Cummins said the engine had to come out if the head gasket looked good after removing the head.  He was sick at heart having dumped all that money in the MONACO from hell.  I helped him flush with soda cause the system wasn't old or dirty much.  After the 4th rinse it felt clean and we charged the system with coolant and water.  300 miles later and coolant analyzed PERFECT.  What does a Cummins cost to overhaul?  Yeah, he said thanks.


I forgot about the block flush.  Yeah, the thermo must come out.  That is the real deal!!!!  They make a adapter from a garden hose to the size of a radiator but the forcefull back flush is driven by a pulse  of air.  just the flow  caused by the water would be worth doing.


Title: Re: coolant flush instructions
Post by: white-eagle on May 11, 2010, 03:28:22 PM
somehow, either i misunderstood big time or they spent extra time and charged for it, but the cost ended up being $170 instead of $120.  Still, i'm not totally unhappy, but the $170, i might have done it.  WW Williams siad they flushed everything 3 times and used all 8 gallons of full strength.  i bought an extra jic.

Title: Re: coolant flush instructions
Post by: eagle rush on May 12, 2010, 08:14:31 AM
Hello everyone, quick question, would it be easier to pull the rad. and back flush upside down to get all the junk out?  Also to inspect the rad. or is there not that much junk flaked off inside the rad. for that much work, is it worth it?  I don't know but I also will have to flush the system soon, Thankyou for all the help!!  Richard

Title: Re: coolant flush instructions
Post by: JohnEd on May 12, 2010, 12:17:10 PM

Do you have any overheating conditions?  Such as?  How high does it go on a long pull with ambient 90 plus degrees?  What temp does it hold on the level doing 60 or ?  Have you shot the temps on the rad with a hand held no contact temp gun?

I think they need more background,


Title: Re: coolant flush instructions
Post by: eagle rush on May 13, 2010, 06:35:49 AM
Hello John, no the bus has not ran in quite a while but soon, If I remember it did not overheat but it did get hot, above 200? Before I run it again I need to flush the system, change the thermostats and do the best job I can (prevent maint.) to make sure it is done right, to run as smoth as possible!! Thankyou for the questions on what to look for, which I will double check and get back to you, The rad and system needs to be flushed, while its down and drained nows the time.   Thankyou John and everyone for the help, Richard