Homemade transmission flushing machine

[hate2work]

Originally Posted By: doitmyself
There seems to be some confusion here. Some are saying to use the OUTPUT line of the tranny. Others are referring to the RETURN line to the tranny.

I was always taught to use the return line as the drain and pour the new fluid in the dipstick tube.



Yes, it's better to use the return line, that way the old fluid in the cooler ( the bottom of the radiator ) also gets pushed out and changed. That might not happen if you use the output line from the tranny.

 

[SteveSRT8]

Sorry I didn't specify that.

My test mule is a reverse flow, comes in from the bottom, so as soon as you disconnect it everything flows out of the SIDE of the radiator.

 

[ecco123]

Originally Posted By: hate2work
Originally Posted By: doitmyself
There seems to be some confusion here. Some are saying to use the OUTPUT line of the tranny. Others are referring to the RETURN line to the tranny.

I was always taught to use the return line as the drain and pour the new fluid in the dipstick tube.




Yes, it's better to use the return line, that way the old fluid in the cooler ( the bottom of the radiator ) also gets pushed out and changed. That might not happen if you use the output line from the tranny.


It seems that is the way to go. I will try to find a point in the return line the closest possible to the transmission to change the biggest possible amount of oil and then refill by the dipstick.

Just one last thing: as I have a drain plug with a magnet, I thought I could remove the drain plug to clean the magnet first, clean the magnet, drain the 5 liters that come out of the pan with that method, then refill 5 liters and lastly do the complete flush with the return line / dipstick method.

The question is: if I do that, would I be wasting the first 5 liters?

 

[digitaldrifter91]

the way that I understand it, your transmission has a big capacity, putting fresh 5 liters then the t-tec only aids in getting new fluid in there.

This is what im going to do to mine.

 

[benzguy]

i built a flushing machine out of a 2 gallon jug and a plastic garbage bag.put a fitting at the bottom of the jug that will hook up to your cooling line then,insert the bag into the 2 gallon jug blowing in it to fill the jug. then fill the bag thats in the jug with the new fluid. put on a airtight cap that also has a fitting for a cooling line.connect the pressure side of the cooling hose to the fitting on the bottom of the bottle and the return cooling line to the lid of the bottle,now start it up ! as the old fluid pumps into the bottom of the bottle it will push the fluid in the plastic bag or (bladder) at the same rate into the return cooling line. since my tranny holds 2 gallons when the bladder is empty my change is done.you can change filters before or after this procedure. i did not change the filter i just wanted to refill a tranny that had 235000 miles worth of worn out fluid. tranny was like new afterward with all its little annoyances gone

 

[artbuc]

Originally Posted By: benzguy
i built a flushing machine out of a 2 gallon jug and a plastic garbage bag.put a fitting at the bottom of the jug that will hook up to your cooling line then,insert the bag into the 2 gallon jug blowing in it to fill the jug. then fill the bag thats in the jug with the new fluid. put on a airtight cap that also has a fitting for a cooling line.connect the pressure side of the cooling hose to the fitting on the bottom of the bottle and the return cooling line to the lid of the bottle,now start it up ! as the old fluid pumps into the bottom of the bottle it will push the fluid in the plastic bag or (bladder) at the same rate into the return cooling line. since my tranny holds 2 gallons when the bladder is empty my change is done.you can change filters before or after this procedure. i did not change the filter i just wanted to refill a tranny that had 235000 miles worth of worn out fluid. tranny was like new afterward with all its little annoyances gone


Very clever! I like it.

 

[GaleHawkins]

Originally Posted By: hate2work
Originally Posted By: doitmyself
There seems to be some confusion here. Some are saying to use the OUTPUT line of the tranny. Others are referring to the RETURN line to the tranny.

I was always taught to use the return line as the drain and pour the new fluid in the dipstick tube.



Yes, it's better to use the return line, that way the old fluid in the cooler ( the bottom of the radiator ) also gets pushed out and changed. That might not happen if you use the output line from the tranny.


We do it both ways. If we pump out using the exit line because it is more accessible I just by mouth blow the old ATF oil out of the cooler and return line before starting the first pump down or before I start the second pump down so that old ATF winds up in the 5 gallon bucket too. We refill through the dip stick tube just to kept it simple. We no longer drain by removing the drain plug/pan drop because I learned even with transmissions with replaceable filters they were always clean it the transmission has life left in it.

I prefer to do it with two people so I so not have to stop holding plastic lines and go shut off the engine when the bubbles start with perhaps oil on my hand. I have had them 'jump' out of the bucket when it start blowing air.

There are many ways to get the dirty ATF out and not remix with new ATF. On some cars it is just removing a clamp in 2 minutes or with others there may be air box/etc to remove to get to that ATF cooler lines. Some only require a screw driver or pliers. Others requires a special tool. Most of the time seems to be spent on pouring in quarts of new ATF. The bubbles start in 30 seconds to a couple minutes at each pump down.

We typically use about 4 quarts more than total system capacity to do a flush. Readings indicate Ford found this gives about 97% new ATF.

 

[DoubleWasp]

For the thermostat transmissions, I get a big piece of clear hose the same external diameter as the external diameter of the transmission filter tube, stick the hose into the trans filter tube's hole in the transmission, the other end into a re-purposed 2.5 gallon oil container filled with the correct trans fluid, sit a big pan under the open transmission, and run the engine until the fluid coming down is perfectly clean.

Then, install a new filter, close up the trans, and pour one quart of fluid into the transmission. Start the engine, let the trans heat up, and carefully fill the trans to the correct level.