Coolant changing procedures

[Adam Zylstra]

I have a '96 Odyssey (30,000 miles) that I want to change the coolant
myself on. There are different instructions in the factory service
manual and the jug of Genuine Honda coolant. The service manual says
"Remove the drain bolt from the rear side of the cylinder block to drain
the block. Apply liquid gasket to the drain bolt threads, then
reinstall the bolt with a new washer and tighten it securely." The
coolant jug doesn't even mention this. Do I really need to do this or
is it a waste of time?

Also, should I use tap water, water from our Brita filter, or distilled
water?

Thank you,
Adam

[rm]

If you don't drain the engine block, you will leave about a quart of
old coolant in there. That drain bolt can be a real bear to remove,
however (real tight).

I generally use distilled water, but it really makes no difference
unless your tap water is really bad.

[Sean M. Vadas]

Can someone elaborate on how the heck you get that bolt off? I couldn't
even get it to budge on my Civic no matter how hard I and several other
people tried. This does not appear to be a hand tool job.

[¤ Basil ¤]

forget the block bolt... just fill up your rad with regular water, close
everything, run the engine at 3000rpm for a couple of minutes, turn it off, pull
the lower hose off the radiator tank, drain completely.

careful not to burn yourself!

then close everything, put the new coolant concentrate (remember to devide the
total capacity of your coolant system by 2) 50% coolant, and 50% distilled
water, or water filtered by a Brita filter or anything with little minerals in
it.

off you go!

BJ

[rm]

>Can someone elaborate on how the heck you get that bolt off? I couldn't
>even get it to budge on my Civic no matter how hard I and several other
>people tried. This does not appear to be a hand tool job.

I admit that I decided against removing the drain bolt after wailing
on it with my trusty 5lb sledge/2 foot breaker bar. The corners of
the bolt were getting a little damaged, so I opted to quit while I was
ahead and just flush the engine via the radiator hose passages.

[Gordon McGrew]

On Wed, 14 Jul 1999 14:52:55 -0400, "¤ Basil ¤" <balj...@decoy.visteon.com>
wrote:

>forget the block bolt... just fill up your rad with regular water, close
>everything, run the engine at 3000rpm for a couple of minutes, turn it off, pull
>the lower hose off the radiator tank, drain completely.
>
>careful not to burn yourself!
>
>then close everything, put the new coolant concentrate (remember to devide the
>total capacity of your coolant system by 2) 50% coolant, and 50% distilled
>water, or water filtered by a Brita filter or anything with little minerals in
>it.
>
>off you go!
>
>BJ
>

I will now add my name to those who cannot remove THE bolt. On my GS-R, I can
only reach it with an extension and when I try to torque it, the socket cams
off. I drained all I could and now periodically empty and refill the reservoir
on the theory that it exchanges with the rest of the system. Maybe a pro can
get the damn thing off with an impact wrench but I suspect that at least some of
them don't bother.

BJ, I am not sure I understand what you are describing. Is this a way to
totally drain the system? Or are you just flushing as much as possible out with
water then adjusting the concentration of coolant?

>
>Sean M. Vadas wrote:
>>
>> Can someone elaborate on how the heck you get that bolt off? I couldn't
>> even get it to budge on my Civic no matter how hard I and several other
>> people tried. This does not appear to be a hand tool job.
>>

[¤ Basil ¤]

for the part that you cannot get to easily (block cavity), you fill the system
with regular water, and rev the engine for a couple of minutes. this should
completely dilute the contents of the block cavity. quickly open the lower rad
hose (watch out for hot fluid) and let it drain again. so, this is how you flush
out 99.9% of your cooling system without dodging the block drain cock/bolt.

BJ