Changing/Flushing Coolant
10-17-2004, 10:19 PM
#1
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Changing/Flushing Coolant
Hey guys, looking at changing/possibly flushing the coolant soon, but I'm confused about a few things (locations of plugs, how to flush exactly, etc.) Is there a write-up or walkthrough on changing coolant on a third gen anywhere? If not can you guys tell me if I'm doing this right, and fill in the blanks where I have questions?..
'86 Z28, 305 Carbureted LG4 with coolant reservoir..
First, I make sure the engine's cool. Then, I'll open the radiator cap a little bit to let the pressure go away, and then I'll take the cap all the way off. I'll go under the car, and drain the coolant from the petcock on the drivers side at the bottom of the radiator, and from how many plugs on the engine block? Where are these plugs located exactly? Then, I take the hose that's connected to the overflow resevoir and disconnect it from the filler neck at the radiator and drain whatevers in there? Once I've done all the draining, I guess I'll do a "fast flush" which only used tap water. Now this is where I don't want to mess anything up. How do I go about flushing the radiator exactly? Won't it hurt the engine with just water in there? Also, how do I flush the block if I wanted to? After I'm done with the flush, connect everything, close the petcock at the bottom of the radiator and install the drain plug(s) in the block, etc...and then fill the radiator with coolant but how much coolant? I have two gallons of prestone 50/50 and then two gallons of distilled water, will that be good enough? Once I add the stuff and the correct amount is added, I'll replace the radiator cap and make sure the arrow is pointing toward the overflow resevoir.
Hopefully you guys can answer some of my questions. I really don't want to mess this up, but I don't want to bring it anywhere, I'd rather get the experience.
'86 Z28, 305 Carbureted LG4 with coolant reservoir..
First, I make sure the engine's cool. Then, I'll open the radiator cap a little bit to let the pressure go away, and then I'll take the cap all the way off. I'll go under the car, and drain the coolant from the petcock on the drivers side at the bottom of the radiator, and from how many plugs on the engine block? Where are these plugs located exactly? Then, I take the hose that's connected to the overflow resevoir and disconnect it from the filler neck at the radiator and drain whatevers in there? Once I've done all the draining, I guess I'll do a "fast flush" which only used tap water. Now this is where I don't want to mess anything up. How do I go about flushing the radiator exactly? Won't it hurt the engine with just water in there? Also, how do I flush the block if I wanted to? After I'm done with the flush, connect everything, close the petcock at the bottom of the radiator and install the drain plug(s) in the block, etc...and then fill the radiator with coolant but how much coolant? I have two gallons of prestone 50/50 and then two gallons of distilled water, will that be good enough? Once I add the stuff and the correct amount is added, I'll replace the radiator cap and make sure the arrow is pointing toward the overflow resevoir.
Hopefully you guys can answer some of my questions. I really don't want to mess this up, but I don't want to bring it anywhere, I'd rather get the experience.
10-18-2004, 02:33 PM
#2
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Join Date: May 2004
Location: Ewing, NJ
Posts: 714
Re: Changing/Flushing Coolant
That's a pretty good flush, however if you really want to make sure everything is clean, I would pick up a flush kit from the parts store. They pretty much just use a connector the slips inline with one of your heater core hoses, and connects to your garden hose. Open the drain plug on your radiator, then run water through everything until it comes out clear.
Good idea to remove your thermostat first, so you know nothing is stuck behind it.
- Justin
Good idea to remove your thermostat first, so you know nothing is stuck behind it.
- Justin
10-18-2004, 03:12 PM
#3
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Posts: n/a
Re: Changing/Flushing Coolant
Originally Posted by Tru2Chevy
That's a pretty good flush, however if you really want to make sure everything is clean, I would pick up a flush kit from the parts store. They pretty much just use a connector the slips inline with one of your heater core hoses, and connects to your garden hose. Open the drain plug on your radiator, then run water through everything until it comes out clear.
Good idea to remove your thermostat first, so you know nothing is stuck behind it.
- Justin
Good idea to remove your thermostat first, so you know nothing is stuck behind it.
- Justin
Anyone know how many plugs are on the engine block, and what's a knock sensor?
Last edited by NJSPEEDER24; 10-18-2004 at 03:28 PM.
10-18-2004, 03:36 PM
#4
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Join Date: Oct 2004
Posts: 29
Re: Changing/Flushing Coolant
Doing a coolant flush is one of the very first things I did as far as car maintenence goes, and it helped me to learn a lot about what and where various parts on the engine are. That said, I made a lot of mistakes that could have been avoided if I knew exactly what I was doing. Here are some pointers that you might find useful:
1. For a full cooling system flush, I'd recommend buying a new thermostat, t-stat housing, coolant temperature sensor (aka CTS), EFE Thermal Vacuum Switch (aka EFE TVS), upper & lower radiator hoses, inbound & outbound heater core hoses, and a new radiator cap. If you want to go even further, you could replace the heater core, but it's a pain in the *** and isn't affected as much as the rest of the parts are.
2. If you plan on using a chemical flush product such as Prestone's radiator flush, drain the radiator of coolant and pour two bottles into the radiator and fill the rest of it up with water. Run the engine at varying RPMs for about 10-15 minutes. Afterwards, drain the radiator again.
3. If you're going to replace the hoses, just go ahead and pull the lower radiator hose off the spout to let the coolant drain faster. The drain plug on the radiator takes anywhere from 15 to 20 minutes to drain.
4. The idea behind flushing the system is to clean the old crud out of the system so it won't "infect" the new coolant. When you remove the t-stat housing to get to the thermostat, run a garden hose through the hole in the engine and look at it as it comes out from underneath the car. It will probably be a green/brown color. Run the water through the block until it comes out clear. Do this with the radiator as well. Don't bother trying to clean the reservoir, as it generally does not clean well (I wouldn't recommend using any chemicals to clean it) and it only costs about $12 at any auto parts store. Might as well get a new hose for it as well, while your at it.
5. Make sure you have the right socket to remove the t-stat housing. It uses a 9/16 socket.
6. Appy teflon tape or some other sealing product to the threads of the EFE TVS and the CTS. If you don't, they will leak coolant once the engine is running. (Note: If your EFE TVS and CTS still work, AND you can remove them from the t-stat housing, re-use them. Mine were impossible to remove so I ended up just buying both of them for about $30 total.)
7. When you replace the heater core hoses, make sure you apply the clamp's pressure immediately after the small notches in the spouts of the heater core. If you don't, your heater core may appear to be leaking coolant into the passenger side floorboard. In actuality, the hose is not securely fastened to the spout and it leaking coolant from the end of the hose.
8. Although most people would recommend a 50/50 mix of antifreeze and coolant, you'll really only need as much antifreeze to protect from the lowest expected temperature your area might see year round. Water is a much better coolant than antifreeze and it is easier for the water pump to get it in and out of the engine. However, water is corrosive and you'll need some sort of corrosion inhibitor if you plan to run a low amount of antifreeze. It also has a relatively low boiling point compared to the amount of heat the engine produces at normal operating temperature, so you'll need to figure out a way to combat that as well. Make sure you use distilled water no matter what you do. At $.59/gallon at Wal-Mart, it's cheap insurance to keep your radiator rust free.
9. Make sure that all your vacuum hoses are reconnected to their proper places when you finish the job (you are undoubtedly going to be removing some vacuum hoses to do all of this). I made the mistake of forgetting to reconnect some hoses and it frustrated me to see the car stall every time I started it until I fixed the leak. I guess what I am trying to say is don't go replacing parts before you check your vacuum lines.
I hope this helped. Here's a link to an article I wrote up on thirdgen.org under the name of Nate86. It's very detailed and takes you through the procedure step by step. Have a look if you still have questions.
http://thirdgen.org/techbb2/showthre...hreadid=250232
1. For a full cooling system flush, I'd recommend buying a new thermostat, t-stat housing, coolant temperature sensor (aka CTS), EFE Thermal Vacuum Switch (aka EFE TVS), upper & lower radiator hoses, inbound & outbound heater core hoses, and a new radiator cap. If you want to go even further, you could replace the heater core, but it's a pain in the *** and isn't affected as much as the rest of the parts are.
2. If you plan on using a chemical flush product such as Prestone's radiator flush, drain the radiator of coolant and pour two bottles into the radiator and fill the rest of it up with water. Run the engine at varying RPMs for about 10-15 minutes. Afterwards, drain the radiator again.
3. If you're going to replace the hoses, just go ahead and pull the lower radiator hose off the spout to let the coolant drain faster. The drain plug on the radiator takes anywhere from 15 to 20 minutes to drain.
4. The idea behind flushing the system is to clean the old crud out of the system so it won't "infect" the new coolant. When you remove the t-stat housing to get to the thermostat, run a garden hose through the hole in the engine and look at it as it comes out from underneath the car. It will probably be a green/brown color. Run the water through the block until it comes out clear. Do this with the radiator as well. Don't bother trying to clean the reservoir, as it generally does not clean well (I wouldn't recommend using any chemicals to clean it) and it only costs about $12 at any auto parts store. Might as well get a new hose for it as well, while your at it.
5. Make sure you have the right socket to remove the t-stat housing. It uses a 9/16 socket.
6. Appy teflon tape or some other sealing product to the threads of the EFE TVS and the CTS. If you don't, they will leak coolant once the engine is running. (Note: If your EFE TVS and CTS still work, AND you can remove them from the t-stat housing, re-use them. Mine were impossible to remove so I ended up just buying both of them for about $30 total.)
7. When you replace the heater core hoses, make sure you apply the clamp's pressure immediately after the small notches in the spouts of the heater core. If you don't, your heater core may appear to be leaking coolant into the passenger side floorboard. In actuality, the hose is not securely fastened to the spout and it leaking coolant from the end of the hose.
8. Although most people would recommend a 50/50 mix of antifreeze and coolant, you'll really only need as much antifreeze to protect from the lowest expected temperature your area might see year round. Water is a much better coolant than antifreeze and it is easier for the water pump to get it in and out of the engine. However, water is corrosive and you'll need some sort of corrosion inhibitor if you plan to run a low amount of antifreeze. It also has a relatively low boiling point compared to the amount of heat the engine produces at normal operating temperature, so you'll need to figure out a way to combat that as well. Make sure you use distilled water no matter what you do. At $.59/gallon at Wal-Mart, it's cheap insurance to keep your radiator rust free.
9. Make sure that all your vacuum hoses are reconnected to their proper places when you finish the job (you are undoubtedly going to be removing some vacuum hoses to do all of this). I made the mistake of forgetting to reconnect some hoses and it frustrated me to see the car stall every time I started it until I fixed the leak. I guess what I am trying to say is don't go replacing parts before you check your vacuum lines.
I hope this helped. Here's a link to an article I wrote up on thirdgen.org under the name of Nate86. It's very detailed and takes you through the procedure step by step. Have a look if you still have questions.
http://thirdgen.org/techbb2/showthre...hreadid=250232
10-18-2004, 03:41 PM
#5
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Join Date: Oct 2004
Posts: 29
Re: Changing/Flushing Coolant
By the way, the knock sensor is used by the ECM to detect pre-ignition/detonation occuring in the combustion chamber. This can be caused by unusally high temperatures, low octane fuel used with a high compression ratio, or too high of timing.
The knock sensor works by "listening" for signs of pre-ignition/detonation and when it is detected, the ECM automatically retards the engine timing as far as it can to keep the problem from occuring.
The knock sensor works by "listening" for signs of pre-ignition/detonation and when it is detected, the ECM automatically retards the engine timing as far as it can to keep the problem from occuring.
10-18-2004, 04:22 PM
#6
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Posts: n/a
Re: Changing/Flushing Coolant
Thanks a lot Nate!
Actually I was on thirdgen.org and saw most of your post, they came up in the search. My main concern is making sure I get all the old coolant out, and flush well with just water. I don't plan on using additives. Thanks again man, it really helped.
Actually I was on thirdgen.org and saw most of your post, they came up in the search. My main concern is making sure I get all the old coolant out, and flush well with just water. I don't plan on using additives. Thanks again man, it really helped.
10-19-2004, 08:56 AM
#7
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Join Date: Oct 2004
Posts: 29
Re: Changing/Flushing Coolant
Sounds like you're pretty much set. That said, I'd recommend just replacing the reservoir because I've found that it tends to leave flaky crap on the side which builds up from old/bad coolant over the years.
Anywho, glad I could help. Good luck and have fun!
Anywho, glad I could help. Good luck and have fun!
10-19-2004, 02:32 PM
#8
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Join Date: May 2004
Location: Ewing, NJ
Posts: 714
Re: Changing/Flushing Coolant
Originally Posted by Nate86
Sounds like you're pretty much set. That said, I'd recommend just replacing the reservoir because I've found that it tends to leave flaky crap on the side which builds up from old/bad coolant over the years.
Anywho, glad I could help. Good luck and have fun!
Anywho, glad I could help. Good luck and have fun!
- Justin
02-10-2005, 06:37 PM
#9
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Join Date: May 2004
Posts: 1,210
Re: Changing/Flushing Coolant
i'm going to do a full coolant flush, so my car has none in it, and refill it.
how many gallons will i need? my car has 14.3L and a bottle of prestone pre mixed dex cool approved coolant is 3.78. obviously ill need 5 bottles, but do i need to TOP off my radiator? if i fill my whole radiator then i just put in till the cool line is reached in the recovery tank? or do i fill the radiator *14.3L?* and then fill the recovery for what it needs to the cold line? what do i do with the coolant? is there a special pan it can go in?
how many gallons will i need? my car has 14.3L and a bottle of prestone pre mixed dex cool approved coolant is 3.78. obviously ill need 5 bottles, but do i need to TOP off my radiator? if i fill my whole radiator then i just put in till the cool line is reached in the recovery tank? or do i fill the radiator *14.3L?* and then fill the recovery for what it needs to the cold line? what do i do with the coolant? is there a special pan it can go in?
Last edited by blind527; 02-10-2005 at 06:39 PM.
02-10-2005, 07:01 PM
#10
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Join Date: Nov 2004
Location: Burlington, KY
Posts: 354
Re: Changing/Flushing Coolant
they make pans to catch all the coolant, although I have to admit, i've never used one... sue me tree huggers!!
I never go that in depth during a flush because I do 2-3 a year to make sure im running good clean coolant. When I bought my car i just put a flush kit on the heater core hose and whenever I do the flush I unplug the stopper at the bottom pass. side of the radiator, take the cap off the radiator, connect a water hose to the flush kit, run it full pressure 10 min.. While its running its course, I take the resevoir off and clean it really good. disconnect water hose, put cap on flush kit and radiator (while full w/ pure water) go run the car for 15 minutes on the street, come back, flush again 5 min. add in my antifreeze and water, use a water/coolant ratio checker (local parts store will have 'em cheap). i go about my day and take a jug of premix w/ me in the car and after extended driving I check the level of coolant in the radiator/resy.
I never go that in depth during a flush because I do 2-3 a year to make sure im running good clean coolant. When I bought my car i just put a flush kit on the heater core hose and whenever I do the flush I unplug the stopper at the bottom pass. side of the radiator, take the cap off the radiator, connect a water hose to the flush kit, run it full pressure 10 min.. While its running its course, I take the resevoir off and clean it really good. disconnect water hose, put cap on flush kit and radiator (while full w/ pure water) go run the car for 15 minutes on the street, come back, flush again 5 min. add in my antifreeze and water, use a water/coolant ratio checker (local parts store will have 'em cheap). i go about my day and take a jug of premix w/ me in the car and after extended driving I check the level of coolant in the radiator/resy.
02-10-2005, 07:35 PM
#11
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Join Date: May 2004
Posts: 1,210
Re: Changing/Flushing Coolant
what are good brands for getting new power steering fluid and brake fluid? i plan on flushing those too and refilling them. how much of each will i need?
oh yeah, same thing with the transmission fluid
oh yeah, same thing with the transmission fluid
02-10-2005, 07:44 PM
#12
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Join Date: Nov 2004
Location: Burlington, KY
Posts: 354
Re: Changing/Flushing Coolant
blind527 do you own a '97 or a 3rd gen?
im pretty sure automatics like the 700R4 take 12-13 quarts of fluid. as for flushing power steering fluid im clueless. brake fluid, check the overhaul proceedures in your maintenance book (i have a Haynes manual, some people have others...) and you should be clear on all that stuff. if you dont have a book, invest in one, its only $15 and WILL get you out of a lot of jams in the future.
im pretty sure automatics like the 700R4 take 12-13 quarts of fluid. as for flushing power steering fluid im clueless. brake fluid, check the overhaul proceedures in your maintenance book (i have a Haynes manual, some people have others...) and you should be clear on all that stuff. if you dont have a book, invest in one, its only $15 and WILL get you out of a lot of jams in the future.
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