Tackling my first coolant flush on my '98 LC tomorrow. Due to unknown maintenance history I am preventively replacing the heater T's and the 6 coolant hoses, as well as replacing the thermostat and gasket. I'm crystal clear on the flush, hoses, T's, and thermostat install, but am wondering if there would be any advantage to removing the old thermostat and flushing the system without any t-stat installed so I don't need to wait for it to open up each time I flush. Could this be dangerous to the vehicle, and if not, am I correct in my thinking that this would speed up the flushing process? I apologize if this has been discussed, after a quick search I could not find anything.
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If you intend to take out the thermostat, just play it safe and go ahead replace the thermostat gasket part number 16346-50010.
Great question! I’m doing something similar and I wondered the exact same thing.
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- #4
Yes, I have the new gasket
ramangain
Clarksonian disciple
The inlet housing may leak a bit, but that's it. No biggie. Just don't have your pets around lapping up the spills etc
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Perfect, thanks a bunch.
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While we're on the topic... After my final flush it'll be safe to assume there will be a small amount of straight distilled water still in the heater cores and likely elsewhere in the system. Is it best practice to divide my overall capacity in half and fill with straight concentrated coolant with that anount, then fill with water until I reach my desired capacity? Or is it better to pre mix before adding and just take the small amount of remaining water into consideration?
Malleus
Far west of Siegen
...or save it for the squirrels.
Malleus
Far west of Siegen
This is just because your sig line indicates you're in the Great White North - the only way to know for sure that you have the correct mix in your coolant/heating system is to measure the mixture with a hygrometer. These should be availble where you are; they're scare as hen's teeth down here. The only way water freezes here is if it's put in the fridge...
I would flush the coolant with the t-stat in. Pulling and putting the t-stat in is going to cause a loss of about a cup of coolant and introduction of the equivalent air. You'll be back bleeding the system again all over. The water pump vane cavity is only about the size of a golf ball, so can loose syphon easily. Same with the T-stat housing.
The LC's system is designed very well and in my experience bleeds very easily. You can encourage air through by burping the radiator hoses.
If I don't have my tools and am bleeding a 4.7 cooling system I just heat cycle the system twice. Make sure you have the heater core open (manual hot - high) and it goes quick.
This is a pretty large capacity cooling system, a cup or two of distilled water aren't going to throw anything off in terms of block protection even at extreme temperatures. If you pull the block drains during your flush and have the heater core open as mentioned, there will be VERY little coolant left. I have verified this by charging my cooling system with air after a full drain and less than half a cup came out of the drain plugs.
The LC's system is designed very well and in my experience bleeds very easily. You can encourage air through by burping the radiator hoses.
If I don't have my tools and am bleeding a 4.7 cooling system I just heat cycle the system twice. Make sure you have the heater core open (manual hot - high) and it goes quick.
This is a pretty large capacity cooling system, a cup or two of distilled water aren't going to throw anything off in terms of block protection even at extreme temperatures. If you pull the block drains during your flush and have the heater core open as mentioned, there will be VERY little coolant left. I have verified this by charging my cooling system with air after a full drain and less than half a cup came out of the drain plugs.
Are you saying no air is introduced to the cooling system when flushing with thermostat in place? I am trying to understand why you worry about a cup of coolant when the old coolant has to be drained.
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- #12
Ended up leaving the t-stat in during flush. Back to my question, am I ok to assume the vehicle will mix the concentrated coolant/water on its own over the next few days, or should I pre mix before filling? Thanks guys.
The system will mix it. No need to premix. When I flushed last year I believe I still had approx 1/2 gallon of water still hiding in the block and heater core etc. in spite of my best efforts to blow out the lines. so I increased the concentration just a bit to keep as close to a 50-50 mix as possible
No. I'm saying flushing without the t-stat in, then installing it after bleeding will. That's what the OP was asking about.
I understand your point now but I didn't see OP mentioned install t-stat after bleeding. I never thought about adding new coolant before t-stat is installed. I always install t-stat after the last drain, then add coolant.
