Alright guys, for all of you who work at shops and lube places. What procedure do THEY follow for flushing tranny fluid if someone comes in and says they want it done, i know that most places don't chance the filter, but im curious as to the way that shops do this. I know how I would do it myself, but im curious as to how shops do it. so anyone with shop experience if you could please let me know.. Thanks!!!

 

Seems to me most shops just drain the pan and leave the fluid in the converter. GM, unlike F**d, decided it wasn't nessacary too put a drain plug in the converter.

 

Most lube places flush the tranny thru the cooling lines from the radiator.

They have a machine with a reservoir that holds, usually 14 qts. of fluid and they hook one cooling line to that( the one that takes the fluid back into the tranny) and the other line coming from the tranny goes into a tank to hold the used fluid.


14 qts of old fluid in, 14 qts of old fluid out.

I only know this because my little brother manages a lube shop.

 

At the transmission shop I worked at, we dropped the pan, changed the filter, and buttoned everything back up, filled the fluid and called it a day.

We flushed the cooler with compressed air and mineral spirits, and Fords have a drain plug for the converter, which is nice.

 

is the fluid in the TC sealed in there or something?
what color should the tranny fluid be? mines alittle brown looking, should i change it soon?

 

We have a machine at work that hooks into the cooler lines. You run the car and it pushes old oil out into the machine which pushes the new oil back into the trans. It runs 18 qts through the tranny(its going to mix some when its in the trans). When thats done the fluid is nice and clean..but the machine has another hose that goes down the dipstick. It then pumps all the new fluid out of the pan. You lift the car up, remove the pan and change the filter. Then reverse the machine and put the fluid back. Now the fluids been flushed and the filters been changed too..I dont think most lube shops bother with the filter change. BUt we do it every time.

 

personally...i just say live with it. if you change your trans fluid on a regular basis....it shouldnt make much difference. I have 2 gms right now that dont have drain plugs on the torque converters, and they both have at least 150,000 miles on them. They're the original trans, and to my knowledge they have only had the fluid changed twice in the trans. still work great.

Its not perfect to have a quart or so of old trans fluid left in the converter, but so what? I dont know how much a trans flushing goes for, but i'd just spend the $8 for the filter, drain and put new fluid in and be done with it. hasnt done me wrong yet.....

 

At my dealership we always drain the fluid and change the filter. We don't have a flushing machine. Even with a flushing machine you won't get the old fluid out of the converter. It may do a slightly better job than the tradional drain, filter, refill, but the difference IMO is minimal.

 

We use to do just the drop the pan routine before we got the new machine. The difference is huge. Just dropping the pan you only change 5 qts. The whole tranny holds 11 or so. so you havent even changed half the fluid. Before when i changed the fluid in a dirty tranny fluid would look dirty still when i got done. Now with the flush machine it makes it look brand new. I know its not a perfect exchange. Thats why it takes 18 qts instead of 11. Run enough extra fluid through the tranny for it to dilute any old fluid.

 

so where are the extra 7 quarts going ? I thought the 700r4 held 11 bone dry.

 

More is flowed through to dilute the old fluid like the guy had just said. I rather pull the pan and change the filter and then get the tranny flushed, because even though those 18 quarts are going through its not going to pick up any heavy debris thats lying on the bottom of the pan.

The other 7 is just in the machine/piping when the flowing is taking place, its not going to make the tranny hold anymore, it can only hold 11 and the other 7 is just passing through.

 

thanks for clearing that up for me.....shame on me for not catching that in the post.... Like I always say..the only dumb question is the one not asked...no need for the atttitude,thanks for the explanation.

 

your very welcome, hey i was just stating a fact, i was not having any attitude , i am just trying to help.

 

so, how much do the shops charge to flush the transmission and change the filter. And also, anyone ever been told after you overhaul the trans, you should change the filter and fluid after about 10,000 miles or so. Said something about breaking in and metal shavings building up. Is this true?? Thanks alot guys this is a great post.:hail: :hail:

 

Well i think in the haynes manual, they say to change the fluid and filter every 40,000 to 60,000 miles. And thats when the tranny is new. I dont know about the cost it would vary alot from place to place, i never had my tranny flushed, i would just change ur own filter and just add new tranny fluid.

 

If you're interested in a way to flush the tranny yourself without paying someone for the labor, to say nothing about the overhead on a fancy, unnecessary machine, these instructions are copied from the AMSOIL website FAQ:

To replace the fluid in the torque converter and oil cooler also, follow these steps.

Step 1. Obtain the total system capacity of the vehicle from the manufacturer or AMSOIL. Have this amount readily available.

Step 2. Disconnect the oil cooler line from the oil cooler. As you may not know which is the pressure side and which is the return side, have both directed so the stream of fluid will be directed toward a receptacle.

Step 3. With another person, be prepared to add ATF to the fill area as it is being pumped out of the oil cooler line.

Step 4. Start the engine, and as the old fluid is pumped out, add fresh fluid to the pan.

Step 5. When either the fluid color brightens or the total capacity has been replaced, shut the engine off and re-attach the oil cooler line. All fluids has now been changed.

This is in the middle of their full explaination of a fluid change, so it ends with warming it up, checking level, etc.

I was doing this for about 15 years before they posted the method on the website. Except I usually did it by myself.