Coolant change fiasco

[booster]

Subtitle-"yes, the factory service manuals can have mistakes".

Not related to our Roadtrek, but certainly could apply to lots of other vehicles, including other class B models.

I went to change the coolant on my 96 Buick wagon yesterday, and figured no big deal, and easy, but messy, to get a complete change as the knock sensors are in the old block drain location. Pop them out, drain the radiator, fill up per the factory service manual procedure to prevent air lock and be good to go.

All went as expected until the last step, fill it back up and bleed air. Manual says fill through the surge tank as there is no radiator cap on this model (reverse flow cooling also) while the little air vent on the thermostat housing is open until it spits liquid. Check. Leave the surge tank pressure cap off and run the engine until it quits bubbling air back into the surge tank, and the bleed valve is all water, making sure the thermostat is full open and the heater on. OK, that is easy, except for the minor problem (figured out way too much later) is that without the pressure cap on, the engine will make steam in the the heads before the electric cooling fan comes on. At first I thought it was hot spots because of air trapped in the heads, and cleaned up the semi major boil over mess, added more anitfreeze, and tried again. Temp gauge was well within OK range through it all, but a bit higher than thermostat temp. Water coming out of the engine was at 190*. After wasting 1/2 gallon of antifreeze and mopping it up off the floor, I turned on the defroster so the AC compressor and the electric fan would run continuously regardless of temperature. Temp dropped a little. Worked perfectly, no boil over, last of air came out, and good to go. I repeated it all the next day, but with the pressure cap on, and all was good.

I know many vehicles let the temp go up 10-20* before they turn on an electric fan, so it is very possible that they might do the same thing. It probably all depends on how the heads are designed and cooled.

I will be doing DW's 2009 CRV next week, and the factory manual says to fill it per their procedure and then run it with the pressure cap on, but loose, until the electric fan cycles at least twice, and then refill and be done. That would imply that the fan setting is lower than the steam making point without pressure, I think. I certainly hope so, I am running out of paper towels to mop up the mess.

[mkguitar]

prestone makes a drain and fill kit which works well on many vehicles- add a T fitting on the heater hose and use pressure from garden hose to push water through.

a few bucks at auto parts store.

don;t mix the orange stuff with the yellow stuff!

Mike

[booster]

Originally Posted by mkguitar

prestone makes a drain and fill kit which works well on many vehicles- add a T fitting on the heater hose and use pressure from garden hose to push water through.

a few bucks at auto parts store.

don;t mix the orange stuff with the yellow stuff!

Mike

I quit using the flush kits a long time ago, although they do usually work OK. They are best if you have the thermostat removed though, as the cold water will nearly always close it.

With the pollution and recycle rules now in place, especially if you are not on city sewer which sometimes allow dumping into the toilet, the flush kits generate way too much waste to haul into the recycling. I have found that as long as I am using the same antifreeze type, not changing like away from Dexcool, I just do the changes more often and drain and refill whatever I can get out. It never comes out looking dirty that way, and I have maybe 2.5 gallons to recycle and catch. And I don't have to remove the thermostat.

We are Dexcool free now, with GO5 in the Buick and Chevy Roadtrek, and have stuck with the Honda antifreeze in the CRV. Honda seems to be one of the few brands of vehicle that really are sensitive to fluids other than factory, especially in the transmissions.

[mkguitar]

yes, I drain what I can to recycle.

and do a pretty good job of collecting the dilute from the flush.

I have stored jugs to allow the water to evaporate, and concentrate the coolant...it takes awhile but I have time and space.

the guys and gals at autozone know me pretty well- it all gets recycled


Mike

[BBQ]

This video pops up on my feed.
Don't know much about this dexcool.
Take it for what its worth.

https://www.youtube.com/watch?v=PbX4CuE8auY