Silverado Transcooler Flush w/Pics

[donnyj08]

As many of you know I've been planning to do a trans cooler line flush for a little while now. I finally got around to it today. I took some pics of the process.

Thanks to fellow BITOG'er Splinter I was able to find the trans cooler line fitting I needed. I used all 4 gallons of Maxlife FS ATF for the change. I decided to use ML ATF instead of a licensed Dex-VI because it meets the viscosity and it is much cheaper. I trust Valvoline's "recommended for".

As stated before I already dropped the pan and changed the Filter at 25k miles so i didn't bother to do that again. I will leave the filter in tact for another 50-75k miles.

I changed the Transfer case fluid as well with a couple leftover quarts of Dex-VI i had laying around. I didn't take pictures of this process as it is just a simple drain and fill. I change the Transfer case before winter each year on the 4x4 trucks i've owned.









I used a measureing cup and water to measure out 2 and 4 qts on the bucket so i could get a reference on how much fluid came out on the first pump. I got out a little more than 4qts before i started to see bubbles.



fluid after first pump



Fluid after the third and final pump. Nice and Red

I also decided to freshen up my P/S fluid before winter as well. I used a "Mixizer" two stroke oil pump to pump out 2oz at a time. I could get about 10oz before i would start to pump the reservoir low. I did 5 drain and fills. total of 2qts replaced. The fluid color improved greatly.

 

[buck91]

Nice job. Did you just run the engine until the ATF started to bubble in the tube?

 

[901Memphis]

Maxlife is good stuff you won't be disappointed.

 

[donnyj08]

Originally Posted By: buck91
Nice job. Did you just run the engine until the ATF started to bubble in the tube?



Yes, I had my father watch it right at the nipple on the radiator. I shut it off at the very first sign of bubbles. This is how I had read online to do it. It worked, Trans shifts like butter!

 

[Brybo86]

I'm kinda surprised you didn't use RP atf...

But nice pics

 

[donnyj08]

Quote:
I'm kinda surprised you didn't use RP atf...

But nice pics




Brybo86, Why is that? @ $14.99 a QT RP ATF is way too expensive.

It also is not a LV fluid.

 

[BigD1]

So you used the line out of the trans cooler that goes into the transmission right? Can't see the nipple in the plastic pack that good. Could you post a link if you have one? I see the tubing size is 3/8.

 

[donnyj08]

Originally Posted By: BigD1
So you used the line out of the trans cooler that goes into the transmission right? Can't see the nipple in the plastic pack that good. Could you post a link if you have one? What size tubing did you use, and where did you buy it?




Yes the line coming out of the top of the transmission is the return line, at least it is on a Silverado. On a different make/model you would need to trace the lines to figure out which one is the feed and which one is the return. It returns from the radiator to my factory external transmission cooler. If you do not have and external cooler it should route directly back to the transmission.

below is a link to the fitting that fit my truck. you can also get it from Amazon. Orielly's had it in stock locally, however.
http://www.oreillyauto.com/site/c/detail...7&ppt=C0073

I bought 3/8 tubing at Orscheln Farm store. It is just a standard 3/8 ID clear vinyl tubing. $0.69 a foot I believe, I purchased 10ft. Lowes or Home depot may have it as well.

 

[BigD1]

Thanks for the information.

I dropped the pan, and changed the filter and fluid about 5,000 miles ago on a 3T40(125C). It still does not have that cherry red color to it like I want, so I guess I will be doing the same type of flush soon.

When I changed it, fluid was actually brownish in color but not burnt, and the GM factory manual said the brown fluid color was normal. Hoping I can get by with just two gallons of the Valvoline MaxLife because it does get expensive. Still going to top off with Lubegard transmission protectant, so that's about $12 more in cost.

 

[splinter]

Nice DIY...good work!

Did you get that Magnefine plumbed in?

 

[daves87rs]

Nice!

 

[donnyj08]

Originally Posted By: splinter
Nice DIY...good work!

Did you get that Magnefine plumbed in?



I did not, I still may purchase one to install in the future. Did you do your flush the same way on your truck? Pump it until it bubbles, fill and repeat?

It seemed to work pretty slick. Overall it seems like a quick mess free way to change fluid.

 

[dlundblad]

Great pics. Good job with the tape too. I am notorious for shooting first and asking questions later.. and making messes half way through the process.

I have yet to do a trans cooler flush, but it'd be interested to help/ attempt.

 

[splinter]

Originally Posted By: donnyj08
..Did you do your flush the same way on your truck? Pump it until it bubbles, fill and repeat?..

Yes, except no bubbles. Shut it down after a quart or two to reduce likelihood of "running pump dry."
Don't know if that makes any difference, though.

Used the 'two man' method (with a lady!) using previously agreed upon hand signals to help minimize miscommunication and undue 'excitement.'

Similar technique on my 722.6 AMG:

Obligatory NNBS 5.3L VVT/AFM LMG w/ 6L80-E underhood:

 

[donnyj08]

Nice pics, splinter.

Looking back, I think next time I will have it filled while pumping. The dipstick tube is large on our trucks and I think I can fill it as fast as it will pump.

A mechanic friend seems to think there is no damage running it until it bubbles. He said those 1-2 seconds of air won't hurt the pump as it should still have plenty of fluid film on the pump.

Next time I'll try it without bubbles.

Thanks for helping me find the Hayden 397 fitting. I certainly appreciate it.

 

[meep]

I've run them "past bubbling" and more like "into foaming" many times with no ill effects. I don't do if often, but it's not under load, the rpms are low, and it's not any longer than needed to get the fluid out.

 

[WillB]

Thanks for the pics. How old was you psf?

 

[donnyj08]

Originally Posted By: WillB
Thanks for the pics. How old was you psf?



I assume it was the FF. The truck has almost 57k miles on it. It wasn't terrible, but I wanted some fresh fluid in it before the winter starts.

I plan to keep flushing it slowly with a couple quarts every 6 months. I've done this on every vehicle I've owned and the P/S systems have always ran quiet and not failed.

I like this truck a lot and I plan to keep it a while, so I'm slowly servicing everything. Many things have already been serviced. I serviced the diffs, trans, and transfer case at 25k miles. So I'm starting round two of my maintenance on many items. The only reason I'd sell it would be to buy a brand new Z71.

I'm impressed with my first GM truck so far.

 

[WillB]

Thanks. My Powersteering pump took a dump and was replaced in June, so the fluid is new. Will do it annually.
Originally Posted By: donnyj08
Originally Posted By: WillB
Thanks for the pics. How old was you psf?



I assume it was the FF. The truck has almost 57k miles on it. It wasn't terrible, but I wanted some fresh fluid in it before the winter starts.

I plan to keep flushing it slowly with a couple quarts every 6 months. I've done this on every vehicle I've owned and the P/S systems have always ran quiet and not failed.

I like this truck a lot and I plan to keep it a while, so I'm slowly servicing everything. Many things have already been serviced. I serviced the diffs, trans, and transfer case at 25k miles. So I'm starting round two of my maintenance on many items. The only reason I'd sell it would be to buy a brand new Z71.

I'm impressed with my first GM truck so far.

 

[smokingun45]

Is a cooler line trans flush any better cost or result wise than draining the pan and refilling several times after driving several miles? I have a 07 Dodge 3500 4x4 with a 48RE transmission. My previous Dodge/Cummins trucks have 5/6 speed manuals, so I'm not well versed in which method is best. Thanks!