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PSA: Flushing and Changing Your Coolant

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17
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22
Location
Bay Area, CA
#1
This took me twice as long as expected, so I'm gonna lay out the steps/tips and tricks so other beginners won't have the same issues as me!

Parts Needed:
- 2 or more gallons of Ford Motorcraft YELLOW Prediluted Coolant (concentrated coolant is also an option)
- 1 bottle of Ford Motorcraft VC-1 Coolant Flush
- 1-2 gallons of distilled or filtered water (I used filtered, but distilled is recommended for the best clean)
- Pair of vise grips or any other mechanical gripping tool (for releasing hose clamp)
- Jack (spare tire jack works perfectly fine)
- Eye/hand protection (I used sunglasses and raw-dogged the coolant with my bare hands, but it's definitely not recommended)
- At least an hour of your time

Steps:
1. Let the engine cool off for at least an hour. I popped the hood and let it rest for 2 hours. Do not remove the cap from the coolant tank; we want the system less pressurized when we initially disconnect the hose.
2. (Coolant Flush) Pour the VC-1 Coolant Flush into your coolant tank. Cap it and start the engine.
3. Over 10 minutes, let the engine idle and rev it to 2500-3500 RPM in intervals. This will allow the coolant flush to circulate through the system. Stop your engine.
4. (Jack) I used the spare tire jack, so your method may be different. If using the spare tire jack or no jack stands, position the jack at the jacking point by the front driver's side tire. Jack fully.
5. (Vise Grips | Auto Fluid Pan) Looking from the front of the car, left of center of the bottom of the radiator, there is a hose about 2 inches in diameter, secured by a metal clamp. Using your Vise grips, loosen the clamp and carefully remove the hose. The coolant will be hot. Make sure your eye protection is good!
6. Remove the cap from the coolant tank and let it drain fully.
7. (Water) Once all fluid is drained from the radiator (note that some coolant will be left in the engine block/hoses), pour your distilled/filtered water directly into the coolant tank (note that all coolant should be drained from the tank at this point).
8. Start engine and, following the same procedure in step 3, circulate the water through the coolant system. Make sure the hose at the bottom of the radiator is still disconnected so the water can flow through! It may take several flushes to get all of the coolant/water/coolant flush out of the system. (Another note: at the top of the radiator, there is a small plastic cap, tire-style, that can be loosened to allow air pressure into the radiator. I'd recommend doing this, as it will be necessary to burp the cooling system afterwards.)
9. (Coolant) Once all fluid is removed from the cooling system, reconnect the hose to the radiator (the clamp should be aligned with the indentations left on the hose). Also close the small plastic cap at the top of the radiator. Remove jack. Pour coolant into the overflow tank. Note that the system will only accept a gallon max the first time around; idling and driving is needed for the cooling system to accept all 1.5 gallons in its capacity.
10. (Coolant) Start the engine and let the system suck the coolant in the overflow tank down. Add more coolant until the system will not accept any more at idle (make sure it doesn't exceed max).
11. Carefully loosen the plastic cap at the top of the radiator mentioned earlier. DO NOT REMOVE; the system is pressurized and much of the coolant in the radiator will spill out (I learned this the hard way). A small amount of coolant will leak out; this is fine. The point of this is to allow the system to burp packets of air left in the engine block and coolant hoses.
12. Drive around; this allows the system to burp and accept more coolant. I'd recommend taking your coolant and funnel with you so you can refill it on the go. Burping the cooling system takes about an hour of driving in my experience; remember to vary your RPMS, but don't drive it too hard as there are still air pockets in the system.
13. You're done! Dispose of your old coolant properly. Also, in the next few days, I'd recommend loosening the cap at the top of the radiator to release any pressurized air, as there still may be some left over.

Final Note: I got a check engine light while circulating the water out of the system. As long as the engine temperature doesn't exceed its normal range (it didn't in mine), your engine will be fine and the light will go away on its own after a few starts of the engine.

~ grigr
 


SrsBsns

Active member
Messages
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702
Location
San Diego
#5
If you're going to do a flush like this, I'd also recommend taking a look at your coolant reservoir and the hoses/connectors there. Not that you need a full flush to replace those, but if you've got the system drained, it would be a good time to replace those with new parts. The reservoir and hoses like to crack and leak over time and they're cheap and easy to replace, especially if you're draining the system.

Edit: Thanks for sharing the write up. Always good to have more walkthroughs for things like this.
 


Last edited:
OP
grigr
Messages
17
Likes
22
Location
Bay Area, CA
Thread Starter #7
If you're going to do a flush like this, I'd also recommend taking a look at your coolant reservoir and the hoses/connectors there. Not that you need a full flush to replace those, but if you've got the system drained, it would be a good time to replace those with new parts. The reservoir and hoses like to crack and leak over time and they're cheap and easy to replace, especially if you're draining the system.

Edit: Thanks for sharing the write up. Always good to have more walkthroughs for things like this.
Thanks for the tip, I'll remember to do that on the next flush. I'm probably gonna get some rubber conditioner for the hoses and weather seals soon.
 


Messages
569
Likes
727
Location
Riverside,CA
#8
I typically flush my cooling systems once a year on my cars. I usually leave the coolant flush in the system for as much as a week. This may be excessive but it seems to clear out way more gunk this way. It has been working well for my two current track cars and worked well in the past on previous daily drivers and track cars. I don't usually see any problems with cooling unless I am on track for 15+ minutes in over 100 degree weather. Otherwise, I can typically stay out as long as I want.
 


Messages
620
Likes
291
Location
Portland
#9
I typically flush my cooling systems once a year on my cars. I usually leave the coolant flush in the system for as much as a week. This may be excessive but it seems to clear out way more gunk this way. It has been working well for my two current track cars and worked well in the past on previous daily drivers and track cars. I don't usually see any problems with cooling unless I am on track for 15+ minutes in over 100 degree weather. Otherwise, I can typically stay out as long as I want.
Hugely helpful, thanks - I was considering adding the VC-1 to my car and then driving to the DIY Garage across town but was a bit worried to do so.
 




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