What coolant fluid is best?
Le Mans Master
Joined: Dec 1999
Posts: 8,540
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From: And on the fifth day, subpoenas were served to Obama senior staff
Re: What coolant fluid is best? (IcemanZ06)
Justin you have a 93 so you should stick with the regular green coolant. Prestone, Texaco and a bunch others make a suitable green coolant.
Good time to remove the radiator and clean out the leaves, replace hoses if necessary, replace thermostat, and replace the radiator cap no matter what!
If you have hard water, go the the food store and see if they have dionized water to mix.
I'm a little crazy to I flush out the system several times with water before the final fill. Takes a lot of time.
I don't use sealant pellets.
Good Luck,
Pete
Good time to remove the radiator and clean out the leaves, replace hoses if necessary, replace thermostat, and replace the radiator cap no matter what!
If you have hard water, go the the food store and see if they have dionized water to mix.
I'm a little crazy to I flush out the system several times with water before the final fill. Takes a lot of time.
I don't use sealant pellets.
Good Luck,
Pete
Racer
Joined: Feb 2002
Posts: 390
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From: St. Louis MO
Re: What coolant fluid is best? (PeteL)
PeteL, why is replacing the radiator cap so important? I'm about to start the radiator removal, clean and flush this weekend and haven't heard that replacing the cap was a needed step.....I will be working on a '94 6 speed coupe with approx. 65K miles. TIA
Le Mans Master
Joined: Dec 1999
Posts: 8,540
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From: And on the fifth day, subpoenas were served to Obama senior staff
Re: What coolant fluid is best? (Topload)
It's just personal experience. I find that cleaning the mating surfaces is important, but the seals on the cap tend to get "stuff" lodged in it and does not seal well - SOMETIMES. It can drive you crazy trying to find the low pressure or leak source. They are so cheap it becomes just a throwaway part for me. Two years - I chuck it.
Similar, if you have a seperate overflow tank, the hoses and connections need to be cleaned or replaced as well. The tank itself should be removed and cleaned. I check for small cracks and leaks at this time.
I usually buy Stant caps, and try to find one that has the correct fit but uses a positive spring pressure vacuum release valve. This valve is the small metalic disc in the center of the cap. If this disc will "dangle" when in position it is not spring loaded, and I find the cap that has a spring loaded "disc".
Pete
EDIT: also don't be suprized if "new" leaks show up in the cooling system when a very old cap is replaced and the mating surfaces are cleaned. What has happened is you now have a properly pressurized cooling system. This is important not only for boil-over protection but also to reduce cavitation in the heads and allow for better combustion and less knock retard.
[Modified by PeteL, 8:40 PM 4/4/2002]
Similar, if you have a seperate overflow tank, the hoses and connections need to be cleaned or replaced as well. The tank itself should be removed and cleaned. I check for small cracks and leaks at this time.
I usually buy Stant caps, and try to find one that has the correct fit but uses a positive spring pressure vacuum release valve. This valve is the small metalic disc in the center of the cap. If this disc will "dangle" when in position it is not spring loaded, and I find the cap that has a spring loaded "disc".
Pete
EDIT: also don't be suprized if "new" leaks show up in the cooling system when a very old cap is replaced and the mating surfaces are cleaned. What has happened is you now have a properly pressurized cooling system. This is important not only for boil-over protection but also to reduce cavitation in the heads and allow for better combustion and less knock retard.
[Modified by PeteL, 8:40 PM 4/4/2002]
Team Owner
Joined: Dec 1999
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Re: What coolant fluid is best? (IcemanZ06)
Staying with the green coolant is the best for pre-Dexcool cars. I have always used Prestone and it seems to give good results. I use distilled water for the final flush and refill.
The service manual recommends flushing 3 times and each time you should let the water get up to operating temp and then cool down before the next flush. Then for the final fill, pour in the 2 gallons of coolant and top with distilled water. Be careful of the bleed valves as they are over the opti and we all know what happens when it gets wet (Hello Jeff? I need a new opti for the vette!)
Also the manual says to let the new coolant go through at least 3 cycles of bringing the coolant up to operating temp followed by a complete cool-down before doing any extended high RPM operation. If you haven't replaced hoses, it may be a good time for that, too.
The service manual recommends flushing 3 times and each time you should let the water get up to operating temp and then cool down before the next flush. Then for the final fill, pour in the 2 gallons of coolant and top with distilled water. Be careful of the bleed valves as they are over the opti and we all know what happens when it gets wet (Hello Jeff? I need a new opti for the vette!)
Also the manual says to let the new coolant go through at least 3 cycles of bringing the coolant up to operating temp followed by a complete cool-down before doing any extended high RPM operation. If you haven't replaced hoses, it may be a good time for that, too.
Racer
Joined: Feb 2002
Posts: 390
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From: St. Louis MO
Re: What coolant fluid is best? (c4cruiser)
Thanks for all the great info. I've noticed how these "little maintenance" jobs seem to snow ball....as long as the rad is out maybe I should just replace the water pump - and since the water pump is out maybe I should just check / replace the opti. - with the opti. out maybe I should just drop in a new cam - whew, a low cost maint job could end up costing a couple of grand! What a great hobby!
