Tranny flush...to do or not to do?

**** PLEASE USE SUBTOPICS BELOW FOR NEW TOPICS ****

Moderator: volvite

User avatar
gilldawg79
Posts: 25
Joined: Sun Apr 11, 2010 9:50 am
Location: Alabama

Tranny flush...to do or not to do?

Postby gilldawg79 » Mon Dec 27, 2010 10:00 pm

I have an '05 Pathy bypassed at around 75K miles. I did a flush and fill at the dealer at around 55K miles. I just turned 100K this evening and wanted to see what you guys think. I have read some negative things about flushes, and since I have 100K miles on it, I am a little leery of a flush to be honest. What about a filter and change. How much is usually changed when you do it this way? I know some of it stays in the torque converter. Are the fluids backwards compatable?

TIA,

Jimmy


User avatar
CiK
Posts: 22
Joined: Mon Mar 01, 2010 3:28 pm

Postby CiK » Wed Dec 29, 2010 10:56 am

What negative things have you heard on transmission flushes? Did anything negative happen after your flush at 55K?

User avatar
disallow
Site Admin
Posts: 2820
Joined: Wed Aug 13, 2008 9:02 am
Location: Winnipeg, Canada

Postby disallow » Wed Dec 29, 2010 11:01 am

Those that have provided input here have said to only use the transmission flush machines that use the transmissions internal pump to provide the pressure. Some flush machines create too much pressure, or push fluid the wrong way inside the trans, which causes problems.

You could do a poor mans flush too. Still big bucks, as the fluid is soooo expensive. But what you need is two 5 gallon buckets and a whole whack of tranny fluid. Disconnect the cooler supply and return lines. Fill one bucket with fluid, and put the supply line into the fluid. Run the return to the empty bucket. Turn on truck and flush away.

You'd probably need some hose extensions to make this really viable. I've never done it, I just do drain and fill. You drain the pan (4 quarts come out) and fill through the dipstick (4 quarts go in). Rinse. Repeat. :)

t

User avatar
gilldawg79
Posts: 25
Joined: Sun Apr 11, 2010 9:50 am
Location: Alabama

Postby gilldawg79 » Wed Dec 29, 2010 11:58 am

I did not have any problems. However, I have read many problems, not necessarily on this site, but other forums. Seems the most prominent problem was diagnosed as debris in a tranny after a flush in vehicles with high mileage and never being flushed earlier in life. Therefore, when it's flushed and filled with new fluid the new fluid breaks down the varnished up insides and the debris is what is causing problems.

User avatar
08Datsun
Posts: 244
Joined: Tue Jan 15, 2008 9:51 pm
Location: Santa Barbara, CA

Postby 08Datsun » Wed Dec 29, 2010 12:31 pm

They usually use a cleaner when they do a flush. This may dislodge some of the debris. I have an old '79 F-150 with a C6 that had fluid in terrible shape that was brown with little black flecks in it. It was shifting a bit erratic every now and then. My mechanic flushed this tranny but recommended not using the cleaner. It essentially pulls out the old fluid and pushes in new fluid. That tranny came back from the brick and still hasn't been re-built.

My last tow vehicle, a '90 Jeep Grand Wagoneer with a 727 tranny had flushes done at 75k and 150k, with normal fluid changes done at 15k intervals. I assume the cleaner was used. No problems there.

These flushes were all done with the machine made by BG.

I've been thinking of getting the Pathfinder's flushed at 60k. I've been doing normal drain and refills up to this point. Drain and refills get about 1/3 of the fluid.

intropiles
Posts: 3
Joined: Thu Dec 30, 2010 6:29 am
Location: Huntington, California

Postby intropiles » Thu Dec 30, 2010 7:44 am

CiK wrote:What negative things have you heard on transmission flushes? Did anything negative happen after your flush at 55K?
Actually, I don't ever heard about the negative things on transmission flushes, so let me know what are they?

scrooks
Posts: 20
Joined: Sat Feb 12, 2011 8:45 pm
Location: San Clemente

Postby scrooks » Mon Feb 14, 2011 4:18 pm

Just ran 12 quarts of "Valvoline MaxLife Dex/Merc (Matic-s) approved", through my 2007 pathfinder @ 73500 miles. I just disconnected the hose from the drivers side of the radiator and into a 1 gallon milk jug. Start the car for approx 5-10 seconds which will drain 1-2 quarts out. Stop the car and then refill with 2 fresh quarts. Repeat that process until you see clean fluid coming out or you can just run 12-13 quarts through making sure to get out "exactly" the same amount you put in. Always a good idea to drive a bit and then recheck the level on the dipstick. This method also worked great on my "06" Titan. Much easier than an oil change...

I've driven for about a month now and the tranny is smooth as silk. Hope this helps.

User avatar
08PathPounder
Posts: 117
Joined: Wed Dec 17, 2014 3:27 pm
Location: NJ

Postby 08PathPounder » Sun Jul 05, 2015 8:47 am

scrooks wrote:Just ran 12 quarts of "Valvoline MaxLife Dex/Merc (Matic-s) approved", through my 2007 pathfinder @ 73500 miles. I just disconnected the hose from the drivers side of the radiator and into a 1 gallon milk jug. Start the car for approx 5-10 seconds which will drain 1-2 quarts out. Stop the car and then refill with 2 fresh quarts. Repeat that process until you see clean fluid coming out or you can just run 12-13 quarts through making sure to get out "exactly" the same amount you put in. Always a good idea to drive a bit and then recheck the level on the dipstick. This method also worked great on my "06" Titan. Much easier than an oil change...

I've driven for about a month now and the tranny is smooth as silk. Hope this helps.


So to do this takes 3 gallons of trans fluid?! Chaaaa Ching. I wanted to do the flush this way but replace it with royal purple in My trans, also plan on putting RP fluids in my transfer case and differentials as well but damn. I saw a YouTube video of a guy who took an air hose and lightly blew the fluid back into the trans in the return hose and then and then turned the car on and replaced the fluid quart by quart as it was flowing out until it came clean... Supposedly only took ten minutes start to finish after he drained the trans pan, replaced the 4 qts and the. Did the return line technique. I'm actually intimidat

User avatar
smj999smj
Site Admin
Posts: 6054
Joined: Sun Jan 22, 2012 11:13 pm
Location: Prospect, VA

Postby smj999smj » Thu Jul 09, 2015 11:24 pm

A typical flush requires the approximate amount of oil as the transmissions capacity, which on most rear wheel drive vehicles is about 10-12 quarts, or about a case of transmission fluid. The transmission "flush" is really just draining the fluid out of the cooler return hose and adding new fluid. This is the best way to get "most" of the transmission oil replaced, but it's almost impossible to get all of the transmission oil replaced. Some Ford transmissions have an access hole in the bellhousing so you can drain the torque converter via a small plug on it. It's too bad more manufacturers don't design this feature into their transmissions.


Return to “2005-2012 Pathfinder (R51)”