1998 4x4 blazer 98,000 miles

I have about a quart and half too much of transmission fluid that I dumped in. My question is should I syphon that out from the dipstick or should I drop the pan, change filter and put new fluid in?
I have heard that with high mileage it's best not to change the old fluid but a tranny guy told me that you can do that now that they have the Mercon V.
Please let me know what you guys think.
I have not changed this filter since I had it when there were 35,000 miles on the vehicle.
Thanks Guys

 

The correct trans fluid is DEXRON®-III Automatic Transmission Fluid .
If it's overfilled, you can disconnect the fluid line to the cooler in the radiator (over a bucket) and drain some out. You may have to start the engine momentarily. Then you can clean up the oil with a brake parts cleaner spray. This would be easier, in my opinion than dropping the pan.

 

What exactly are the negatives of overfilling the tranny? I know of all the fluids that's one you wanna avoid over filling..but isn't there some sort of overflow valving or something to eliminate the buildup in pressure?

 

A slight amount of extra fluid isn't going to matter. But get up to the 1/2qt to 1qt over and you will start to get fluid up into the moving parts which will aerate the fluid causing it to foam and puke out the breather. Not to mention that foamed ATV doesn't protect anything in the transmission lubrication wise.

 

Yep, its got a breather hose on top of the tranny right behind the bellhousing. If its overfull it'll puke out when it gets hot. Its worse to run it while low on fluid.

 

Easy way I've done it is to use a vaccuum pump with some hose (windshield washer hose works perfect), down the dipstick tube and pump out the extra.