I have a '96 EX with F22B1 engine, and from what I can tell it has ATF cooler lines going into the radiator.

If that is the case (that certain Honda motors have radiator cooling lines), then why hasn't there been much more posting on flushing your ATF fluid this way?

This is a common method on Toyotas, Mercedes, etc ... basically any car that has ATF cooler lines that are easily accessible and can be tapped with a clear flexible hose.

Why not Hondas? It's a much more complete method, and will really help those poor souls who accidentally put the wrong fluid in the transmission to begin with ...

 

There is a video on youtube that shows this method of changing the fluid.

I only owned manual transmission accords, so I don't know if there are any concerns. My biggest would be running the transmission dry. The other would be having rusted/corroded transmission lines to the radiator. If I broke or stripped one, then I am in trouble.

Hopefully others with automatic transmissions can comment on this.

 

Both lines have rubber hoses coming from the radiator, fitting over 3/8" pipes above the tranny with spring clamps. So I would just pull one of the rubber hoses off, as you would do on a Toyota engine.

Did you find a Honda video? I've seen one which is generic ... would be great to see if someone has done this on their Honda.

 

Search "10 min automatic" on youtube for video. Note which line (supply) he uses. You want the discharge from trans line. He is working on an Accord so yours should be same (furtherest towards pax side).

I did this job solo on a Subaru w/o issues. Notice how quickly the fluid drains. I drained/filled reservoir, and ran engine about 10 secs to discharge 1-2 qts, refill reservoir, repeat until clean fluid is appears at catch pan. A white bucket and/or clear jumper hose helps to see fluid. You need about 3/8" ID hose to fit over end of trans line fitting. Measure hose to be sure.

good luck

 

You're right, my bad ... that is an Accord.

And the trans cooler lines are in the same place as in mine. The only thing I would propose to change in his video is to blow out the return line when you drain the pan and before the initial refilling.

So, why aren't we prescribing this as the standard way to flush your transmission fluid? Doing repeated drain-and-fills is not going to do nearly as good a job as one drain-and-fill with a fluid line flush ... or is there something in the routing of the fluid to the lines that makes it less than ideal?

 

Complexity and cost......do a drain and fill every 15~30k and no worries.....oh unless we are talking about the 6th gens, all bets are off on thoses.......5th gen with 380K and just simple drain and fills. Pilot, bought with 45K, did drain and fill shortly after ownership....since then, drain and fill every 15~20K and at 120K and fine.

IMHO, keep up with it and there is no reason to "go deep". Only reason to do that is if you let it go too long and even then I would still do three drain and fills. At ~$8 a quart, running ~$96 worth of fluid thru a trans in no time is a long shot, waste if money.

Again, IMHO, even if you buy a car with no history of the changes.....don't shock the system. A cycle of a few drains and fills and you will be fine.

 

Even this method (using the hoses) still relies on the new fluid mixing and diluting the old fluid. So it's not really true that this method will do a "better job".

IMHO it comes down to which method do you think is easier and/or less messy & less pain. Sometimes (northern states) you have problem disconnecting the hoses because they're corroded & the fittings break off.

 

There is little mixing since old fluid is first drained from reservoir and new fluid installed. Old fluid is displaced as new fluid is pumped from reservoir into trans. Video highlights the transition from dark to clear red over a few secs. This is a good procedure when you don't know condition of fluid or suspect is over-due for a change.

I agree w/ PM that this method is unnecessary as long as fluid is changed every 2-3 yrs. I've only used procedure one time to remove fluid that was overheated due to a failed ATF coolant line (subaru).

good luck

 

A sump drain followed by a cooling line flush should remove 90-95% or more of the old fluid in the transmission ... that includes torque converter and pump.

But the question of how much less thorough a series of drain-and-fills is really depends on the overall capacity of the tranny and how much you can replace each time.

On "other" car trannies that have 8-10 qt capacities, a drain-and-fill of the sump contents alone gets you maybe 50% new fluid each time. So three drain-and-fills would get you to 87.5%. Not great if you leave over 10% old dirty fluid in the system.

I'm having a hard time finding reference to the overall fluid capacity in the Honda Accord tranny, but found one reference to it being only 3.5 qts. If this is the case and you are able to get 2qts out in each drain-and-fill, that's 57% new fluid new time, and 92% for three. If you can get closer to 2.5 qts out each time, your numbers are closer to 72% and 98%.

So if the overall fluid capacity of the tranny is small, that would explain why there is no burning desired to do a cooling line flush.

 

The 94-97 Accord AT has 6.3 qts total fluid and 2.5 qts to drain reservoir.

good luck