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transmission flushing question

shady

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I'm going to flush my trans, but I dont know which line is the return line in a stock set up (top or bottom on radiator). I think its the top? but its better to ask first i guess
 
Depending on how bad your fluid looks,,, I just did a double fluid change and it worked out just fine. Yeah there still some older stuff in there, but the color on the dipstick went from a brownish color, mainly just a dirty look, to a nicer pinkish cleaner look...

I changed the fluid with filter two weeks ago, then again this past week before a trip to SoCali. also changing the fluid and filter again.

Heard too many horror stories about people flushing trans systems out and then having it quit working on them a short time later. I'm hoping the double fluid change isn't as harsh of a fluid cleanliness and consistancy change to harm anything internally. Not sure if anything I am saying has any merrit to it, but i'll let ya know how it goes if anything bad happens.. :D


Pretty sure the top line is the return to trans line, heard different answers on this before though. Been awhile since I have messed with mine, so I really don't remember...

Sorry didn't really answer your question, possibly just a word of caution about full on flushing the system.
 
Some of them stories may come from people that already had a noticeable issue when they did it:dunno: I've heard the same thing though. I cant for the life of me figure out why it would harm anything. but i've heard it from some mechanics too:confused: I still think it would be better????
 
Sometimes flushing an automatic does more harm than good....especially if it was not maintained properly,if the fluid got dirty or sludged up,loosening all that crud can plug up tiny orifices in the valve body valves and passages...also the laquer built up around other worn parts may be whats sealing them up well enough for the tranny to work & shift OK,but when its removed ,the prblems start...

I dont understand those "flushing machines" ,how do they separate the different fluids??--I mean,if a guy came in with a Honda that requres a specific fliud,and gets his tranny flushed,does the next customer with a GM tranny needing Dextron get a mixture of the used Honda fluid and whatever else in the machines tank??--they "recycle" the fluid-- I would think mixing different fluids would spell disaster ...
I could see if only NEW fluid gets pumped in one end while the used fluid is pumped out ,but I am under the impression those machines recycle the fluid...am I mistaken??..
 
That tci link is just what I was looking for:thumb:. I thought it was the upper line and when I seen that page I knew why. I've seen that before looking for line size for my kids truck. Thanks

The current fluid dont look burnt but I know its old. I'm not using a machine so it wont be knocking anything loose that just a normal fluid change wouldn't. I'll be un hooking the return line after the cooler and running a line from it to a bucket. Then I'll start it in park while continuosly pouring new fluid down its throat(thee man job). After the fluid starts coming out real clean looking I'll hook it all back up then drop the pan and do a normal fluid filter change. No unnormal pressures or anything, just the normal stock pump doing what it does:dunno:. I cant really see that hurting it. But if it does then my trans had issues that I just hadnt noticed yet and probably needed rebuilt anyway.
 
Then I'll start it in park while continuosly pouring new fluid down its throat(thee man job). .

I'll tell you right now from personal experience, you won't be able to keep up with the fluid flow doing it this way. It pumps out way faster than the dipstick tube will allow incoming flow.
 
If the fluid is not burnt or seriously discolored, just drop the pan, replace the filter and fluid, then a week later, do it again, you'll be suprised at the difference it makes in fluid color & smell.

Pumping all that new fluid through a dirty trans filter isn't going to do you much goos either. Replace the filter, run it, let it filter o ut more crap, then replace it again.
 
Just pay 100 bucks and have the shop do it. You'll be paying close to that much in fluid yourself. And they can do a complete flush, not just a partial change.
 
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