This method is a lot easier than using the engine coolant drain bolts, because those bolts are often seized and are hard to get to.

WARNING
Make decisions carefully. If you choose to use this method and ignore the fact that I say to use undiluted antifreeze and you use 50/50 mix, your end result will be a 75/25 mix (75% water, 25% antifreeze). If you decide to just fill completely with 50/50 mix after you flush the engine with water, you will not end up with a 50/50 mix in the engine. Because of the water still in the engine after flushing, you will probably end up with around 65/35 (65% water, 35% antifreeze).


Materials needed:
-1 gallon 100% undiluted antifreeze
-2 gallons distilled water (at least)
-Bucket
-Jack
-Jackstands
-Funnel
-Socket wrench with extension and 12mm socket (keeps your hands away from the scolding hot coolant while bleeding).



Procedure

Preliminary: Set the e-brake. Jack up the front of the car and put on stands. Get a bucket under the radiator, and slide/turn your heater temperature all the way to hot.

1. Drain the radiator by removing the cap at the top and unscrewing the drain plug at the bottom.


2. Put the drain plug back in and fill radiator with distilled water.

3. Put the radiator cap back on and run the engine for around a minute and then turn it off.

4. Repeat steps 1-3 until the only thing draining out of your radiator is clean water.

5. Drain the radiator for the last time.

6. Put the radiator drain plug back in and lower the car to the ground.

7. Carefully remove the cap (it may shoot everywhere, get a rag). Fill the radiator with half of your coolant systems capacity (see information below for your engine's numbers) in 100% undiluted antifreeze

8. Fill the radiator all the way up to the bottom of the filler neck with water (you now have a 50/50 mixed solution in your system)

9. Add 50/50 mix of water/antifreeze to the coolant reservoir.

10. Leaving the radiator cap off, start the engine and let it warm up to normal (radiator fan comes on twice).

11. Bleed the system of air from the bleed bolt on the front left corner of the head. Let it flow until a steady stream comes out. Tighten bleed bolt to specs. (If you don't have a torque wrench just get the bolt tightened snug. It just needs to stay screwed in by itself. Be very careful tightening). If you can't find the bleed bolt, your bleed bolt may be at the thermostat housing if it isn't at the front of the engine. 96-00 Civics and 96-97 del Sols don't have a bleed bolt and you simply idle the engine with the radiator cap off and let the air bubbles escape.


12. Turn off the engine.

13. Fill the radiator back up to the bottom of the filler neck with 50/50 mix of water/antifreeze, and fill the reservoir to the max mark with 50/50 mix of water/antifreeze. Install radiator cap.



Half of coolant capacity:
This is the amount of 100% undiluted antifreeze you will add in step 7. This is half the capacity, I have already done the math for you.
Please note that if your Civic is made in Canada, or any other country, the model numbers next to the amount are incorrect for you.
(For 1996-2000 Civics, Canadian Si=USDM EX, Canadian SiR=USDM Si. I'm not sure about the rest.)
The engines and capacities are still correct though, if your car has that engine.

(MT=Manual Transmission, AT=Automatic Transmission)

84-87 Honda Civic/CRX
All: 0.68 Gallons

88-91 Honda Civic/CRX
All SOHC: 0.59 Gallons
All DOHC: 0.60 Gallons

92-95 Honda Civic/93-95 Honda del Sol
D15B8 MT: 0.56 Gallons (Civic CX)
D15Z1 MT: 0.54 Gallons (Civic VX)
D15B7 MT: 0.56 Gallons (Civic DX/LX, del Sol S)
D15B7 AT: 0.54 Gallons (Civic DX/LX, del Sol S)
D16Z6 MT: 0.56 Gallons (Civic EX/Si, del Sol Si)
D16Z6 AT: 0.58 Gallons (Civic EX, del Sol Si)
B16A3 MT: 0.66 Gallons (del Sol VTEC)

96-00 Honda Civic/96-97 Honda del Sol
D16Y5 MT: 0.55 Gallons (Civic HX)
D16Y5 AT: 0.56 Gallons (Civic HX)
D16Y7 MT: 0.55 Gallons (Civic CX/DX/LX, del Sol S)
D16Y7 AT: 0.54 Gallons (Civic CX/DX/LX, del Sol S)
D16Y8 MT: 0.55 Gallons (Civic EX, del Sol Si)
D16Y8 AT: 0.56 Gallons (Civic EX, del Sol Si)
B16A2 MT: 0.66 Gallons (Civic Si)
B16A3 MT: 0.66 Gallons (del Sol VTEC)

01-05 Honda Civic
D17A1 MT: 0.66 Gallons (Civic DX/LX/VP)
D17A1 AT: 0.65 Gallons (Civic DX/LX/VP)
D17A2 MT: 0.66 Gallons (Civic EX)
D17A2 AT: 0.65 Gallons (Civic EX)
D17A6 MT: 0.65 Gallons (Civic HX)
D17A6 AT: 0.64 Gallons (Civic HX)
K20A3 MT: 0.90 Gallons (Civic Si)

94-01 Acura Integra
B18B1 MT: 0.73 Gallons (Integra RS/LS/GS/SE)
B18B1 AT: 0.89 Gallons (Integra RS/LS/GS/SE)
B18C1 MT: 0.89 Gallons (Integra GS-R)


(If your engine is not in this list, just search the web for the dry coolant capacity and then divide that amount by two. Or look in the Honda Service manual for "for overhaul" capacity. Pay attention to units of measurement.)



Recommended simultaneous maintenance:
-New thermostat if it hasn't been replaced recently
-Inspect radiator hoses






Pictures were borrowed from the 92-95 Civic Honda Service Manual. These pictures should be applicable to all 88-00 Civics and del Sols.

 

niiiiiiice!!!!!! good job broski!

 

nice write up trust. do you know how often i flush the coolant?

 

thanks

every 30,000 miles under normal conditions

 

nice write up ! stu

 

What's the B16A2 capacity? Can't find it anywhere.

 

now added to DIY

please note that the amount i wrote in the DIY is only half the capacity, because this is the amount you need to know for this DIY