Changing Radiator coolant... - Honda Prelude Forum

Jordan_4WS · 06-21-2002, 08:41 PM

So how exactly is this done? I know its more involved than just changing motor oil and involves some bleeding. I'd like to do this next week (my service manual wont be here for another 2 weeks), so can someone explain the process?

Also, is there a difference in what coolant I use, or is it insignificant? Also is there a difference between replacing coolant, and flushing the system (just two expressions I have heard)? Finally, the service schedule says this should be done every 45k miles, should it be done more often than this? If so, how often should it be done?

Thanks, Jordan

Mike95lude · 06-22-2002, 02:31 AM

good question. I want to completely flush all my coolant and replace it too (haven't done it before). Any clarification on the matter would be great

Tola · 06-22-2002, 09:35 AM

Look under the radiator, there's a white plug on the driver side. Unscrew that plug, fluid comes out. Take off the radiator cap for it to drain faster. Once that's done, there's a bolt behind the engine block, it's under the oil filter, you unbolt that and coolant comes out of there. I have NEVER drained the coolant from the engine block because I cannot find that bolt!! Also, empty out your reseviour. When everything's all drained out, there's a 10mm bolt on top of the T-stat housing, just loosen that. It's the bleed valve. Fill the radiator with a 50/50 mix. Then go on to fill your reseviour to the "max" line. Then start the engine and let it idle, add more coolant until it stops going down. Tighten the bleed valve and put on the radiator cap. I'm not too sure if this is exactly the way the Helms said to fill it up, but I find that it works best for me.

I used to use Honda antifreeze because I've heard that others will shorten the life of your radiator. But now Honda only sells a pre mixed 50/50 solution for the same price so I no longer uses it. I just use regular Prestone. I'm not having any problems with it.

I replace my coolant every year, which is about 20k. It's cheap, relatively easy, preventive maintence.

glitched · 06-22-2002, 11:38 PM

in order to flush it urself u should let water from a garden hose run thought the top and out the drain, (keep the in car heater on high!!!), and start the car while the water is running through, do this for a couple of min, then fill it up with a 50/50 mix... remember if u change the 50/50 recipe, more water means less chance of boiling at extremmely high temps but more of a chance of freezing... more antifreeze means more protection from freezing, etc...

elprez2000 · 06-23-2002, 05:11 PM

would it be a good idea to run all water in like the summer? sorry if it sounds stoopid but for some reason that idea just came to mind

F22alude · 06-23-2002, 07:26 PM

You don't want to just run water since water has an oxidizing and corroding effect on metal parts (especially from tap). Antifreeze/Coolant has anti-corrosion mixed in it. I recommend a 60/40 mix in the summer (water:coolant).

Jordan_4WS · 06-24-2002, 03:00 PM

Quote:

Originally posted by elprez2000
would it be a good idea to run all water in like the summer? sorry if it sounds stoopid but for some reason that idea just came to mind

Straight water also has a lower boiling point that radiator fluid.

-jordan

kevie88 · 06-24-2002, 07:25 PM

I've run straight water with 'Water Wetter' in my race bikes and it's always worked very well.. straight water is bad for corrosion but Water Wetter really does help!

Jape · 06-24-2002, 11:51 PM

what do u guys catch the fluid in? I was thinking of letting it drain into the street so all the cute puppies will drink from the sweet nectar of the prelude.

lol.. will it kill grass tho?

Jordan_4WS · 06-25-2002, 10:31 AM

Quote:

Originally posted by Jape
what do u guys catch the fluid in? I was thinking of letting it drain into the street so all the cute puppies will drink from the sweet nectar of the prelude.

lol.. will it kill grass tho?

I use a large (15 quart) oil container. I figure 1 gallon for the old radiator fluid and than 1-2 gallons for running the car with the hose going through. 15 quarts is more than 3 gallons, and it was able to hold more than enough fluid, hell, I probably could have also changed my oil into the same pan with no problem.

-Jordan

Mike95lude · 06-25-2002, 11:45 AM

I could never find the bleed valve on the thermostat when I changed mine two days ago.

brendon2k · 06-25-2002, 01:59 PM

Where exactly is the t-stat housing and the bleed valve? I need to do this today when I install the water pump.

Jordan_4WS · 06-25-2002, 03:36 PM

Quote:

Originally posted by brendon2k
Where exactly is the t-stat housing and the bleed valve? I need to do this today when I install the water pump.

In the owners manual, under the section on changing radiator fluid, they have a really straightforward image. There are two bolts next to each other, the bleeder valve is the one with a hole in the top of it.

-jordan

glitched · 06-26-2002, 12:05 PM

last sunday when i was at the drags the announcer was tellin peeps to drain the antifreeze and just run water for racin...(for ur car's protection, but mostly so theres less of a chance for antifreeze on the track)

also, it could just be me, but i gave up on the bleed bolt... i could not loosen that thing for the life of me.

Jordan_4WS · 06-26-2002, 02:14 PM

Quote:

Originally posted by glitched
also, it could just be me, but i gave up on the bleed bolt... i could not loosen that thing for the life of me.

I had no problems loosing it. Are you sure you have the right bolt and are turning it in the right direction?

-jordan