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Honda auto transmission fluid change

I just changed the transmission fluid in my Accord V6. While researching the change, I found a lot of conflicting information. Honda recommends draining and refilling it three times and driving it around the block between #2 and #3. Haynes says to do it once, or maybe twice with the same around the block thing. I’ve also seen it said on this board that it’s OK to flush the fluid as long as you use the transmissions hydraulic pump to move the fluid. What are your opinions?

BTW, how much fluid remains in the torque converter? That will help me determine whether the Honda or Haynes method is acceptable.

You should either do what Honda recommends or if you are servicing on a regular basis, just once will be ok. What year?? How many miles?? Has it ever been serviced before?? Has it been serviced on a regular basis?? (Every 25-30k miles)

Make sure you use ONLY Honda fluid. Nothing else.

Dont pull the cooler lines and pump it out, you have the potential to ruin your transmission.


I’ve always been curious and I was wondering if you could help me to understand, but why does unhooking the cooler lines and using the transmissions own pump cause damage? Does it have something to do with a pressure differential or something of the sort?

Hopefully someone with more expertise than me give a definitive answer.

But my own impression of the process is that the pump simply runs too fast with too much pressure for our human activities to keep up with certainty. If whatever feed process you’re using gets behind the pump you can burn up the pump via pumping either just air or maybe foam.

…I’ve got no direct expertise or certainty about that. Its what I’ve had explained to me.

Well, under those specific circumstances then theoretically a method offered by the T-Tech machine should be fine as it uses the outflow of fluid to push new fluid back through the lines at the same rate. That is of course assuming the information you’ve been given really is the real issue.

I’d be very interested in hearing additional information/opinions on this issue.

If the T-Tech machine is one of the fluid exchangers, then yes - it is fine. Its designed to do that and replace the fluid at precisely the same rate as it takes it out. I think the DIY cooler line method is unable to do that precision of matching up rates.

Of course, I’ve also never tried it. Nor have I operated a fluid exchanger. So I too and interested in hearing from others.

The problem with using the transmission’s own pump to empty the fluid is that the pump uses the fluid to lubricate itself. By the time we would notice that all the fluid had been pumped out and turn off the car, the pump would already have been running several seconds without that lubrication. I suppose most of the time it might be ok, but I wouldn’t risk it.

I’ll share my experience about my '98 Accord 4 cyl (bought new and now with 245000 miles). I had the transmission fluid power flushed (or so I thought) at 40k mile intervals. At 239k miles the transmission was slipping in the 1-2 upshift. I took it to the dealer for a diagnosis in July. The fluid had a burnt smell and there were metal filings on the magnetic drain plug.

I was told that Honda does not recommend power flushing. Simply drain and fill. They acted like this had been the recommendation forever. I showed them my copy of the advertisement that was on their counter in 1999 that recommended power flushing. I had requested power flushing at every service. Later I checked my records and found that sometimes I had received a power flush and other times I had received a drain and fill.

It seems Honda changed their recommendation sometime between 1999 and 2010. I suspect the transmission problems in the 2000-2002 period had a lot to do with it.

I was upset about the transmission failure. They asked me how many miles I expected to get out of an automatic transmission. I stated that with the regular service that I had been paying for, it should last the life of the car.

I ended up buying a rebuilt trans from Jasper and having the dealer install it. The Jasper trans is guaranteed for 100k miles or 3 years. I’ll take it if for drain and refill every 30k miles and see how long this one lasts.

That “lifetime of the car” thing is tricky since there is no clear definition of what that means. For many, if not most people, a car “lives” as long as the engine and transmission both work. So, by that definition, every transmission lasts the lifetime of the car. Its tricky to tell what sets the “lifetime” for your car. The only complete death of any car really comes from rust or collision damage since anything else can be fixed or replaced.

That said, the thing about automatic transmissions is that they are actually wear and tear items - not all of their parts are, but the clutches certainly are. I’m not sure I’d be upset with an auto trans that made it to 239K.

“They asked me how many miles I expected to get out of an automatic transmission.”

Unless you’re driving mostly highway 239k is a good distance.

This is one reason that few cars make it past about 250k miles. Any transmission will fail at some point, 239k is pretty good. At this point it doesn’t make economic sense in most cases to repair it.

2005; 75,000 miles, second change. how much fluid does the torque converter hold, transman?