Transmission flush or drop the pan and fill?
#1
Transmission flush or drop the pan and fill?
Hi guys. I just got a 2001 F150 5.4L lariat. I always like to replace all the fluids when I get an used vehicle. The truck has 159K miles on it. The tranny shifts fine from I can tell. I have read and heard the stories about flushing it with this kind of mileage.
The fluid on the dip stick is not bright red, is like a red brown color. I doesn't smell burnt. The place I had always taken my vehicles to do the "tranny flush" uses a machine that put the fliud thru the tranny fluid dip stick with a small double hose. They turn the vehicle on and the machine has some kind of sensor that will tell when the fluid is clean. The machine then sucks some of the old fluid out and fill some of the new. It continues to do this until the sensor senses the fluid is clean. Will this machine be a safer bet as doing the tranny service? I don't see this machine pressurizing the system. I asked the manager one time about and they said they used to have old flushing type machine but they were having alot of problems after the flush so their company switched to these machines. They say is safer with this machine.
I have done my 1998 firebird transmission service like this three times. I did the 1st one with 46K, and two more after that. The firebird has 139k and not a since issue with the transmission.
I'm very familiar with doing the dropping the pan, change the filter and put in the lost fluid back in.
What to do guys think? Thanks.
The fluid on the dip stick is not bright red, is like a red brown color. I doesn't smell burnt. The place I had always taken my vehicles to do the "tranny flush" uses a machine that put the fliud thru the tranny fluid dip stick with a small double hose. They turn the vehicle on and the machine has some kind of sensor that will tell when the fluid is clean. The machine then sucks some of the old fluid out and fill some of the new. It continues to do this until the sensor senses the fluid is clean. Will this machine be a safer bet as doing the tranny service? I don't see this machine pressurizing the system. I asked the manager one time about and they said they used to have old flushing type machine but they were having alot of problems after the flush so their company switched to these machines. They say is safer with this machine.
I have done my 1998 firebird transmission service like this three times. I did the 1st one with 46K, and two more after that. The firebird has 139k and not a since issue with the transmission.
I'm very familiar with doing the dropping the pan, change the filter and put in the lost fluid back in.
What to do guys think? Thanks.
#2
Senior Member
Now that is kind of a tricky situation. It's common understanding that when you change the fluid at a high mileage when it hasn't been changed in so long, it generally causes more problems...
I however have never had this problem, I have changed high mileage transmissions before without so much as a hiccup. My bronco had similar mileage, and I changed the fluid soley due to the fact that I was getting torque convertor shudder. Changing the fluid alieviated the problem. However, on these transmission I don't know how they would react. I would suggest changing just the fluid in the pan, and the filter. It'll only change about half the fluid, but you get a fresh filter in there...
Other than that I wouldn't change all the fluid completely unless it gets burnt.
I just changed the fluid on my 2001 with 100k miles. The fluid was nice, red and clean still when I drained it but I changed the fluid in the pan, and drained the torque convertor.
We should get some more opinions.
I however have never had this problem, I have changed high mileage transmissions before without so much as a hiccup. My bronco had similar mileage, and I changed the fluid soley due to the fact that I was getting torque convertor shudder. Changing the fluid alieviated the problem. However, on these transmission I don't know how they would react. I would suggest changing just the fluid in the pan, and the filter. It'll only change about half the fluid, but you get a fresh filter in there...
Other than that I wouldn't change all the fluid completely unless it gets burnt.
I just changed the fluid on my 2001 with 100k miles. The fluid was nice, red and clean still when I drained it but I changed the fluid in the pan, and drained the torque convertor.
We should get some more opinions.
#3
Senior Member
I would do a pan drop and filter change, but I would not do a flush at that mileage. The flush is what causes problems - all the debris/particles are dislodged and end up getting in areas of the transmission that you don't want. Nothing is disturbed when you do a pan drop - granted not all the fluid is removed, but since your transmission shifts fine now, it's a much less risky alternative.
#4
Looking for a Henway.
iTrader: (2)
I would (and did) drop the pan and change the filter.
I also added a drain plug to my pan so over the next few weeks I can drain and replace the fluid 2-3 times to basically end up with a complete fluid change.
I also added a drain plug to my pan so over the next few weeks I can drain and replace the fluid 2-3 times to basically end up with a complete fluid change.
#5
Senior Member
well You don't really need to "flush" the system either. You can remove nearly all of the fluid buy draining the torque convertor as well. The TC has a drain plug, and it holds like 5 quarts or something like that. The rest of the fluid would be in the cooling lines and the cooler. You can disconnect that from your transmission, and blow compressed air through to get the fluid out. You only need 20psi or so of air, just enough to move the fluid through, not force it. After that it will take nearly 14 quarts to fill the transmission up properly.
#6
Looking for a Henway.
iTrader: (2)
well You don't really need to "flush" the system either. You can remove nearly all of the fluid buy draining the torque convertor as well. The TC has a drain plug, and it holds like 5 quarts or something like that. The rest of the fluid would be in the cooling lines and the cooler. You can disconnect that from your transmission, and blow compressed air through to get the fluid out. You only need 20psi or so of air, just enough to move the fluid through, not force it. After that it will take nearly 14 quarts to fill the transmission up properly.
#7
Senior Member