Trans fluid change

gmcman

Original poster
Member
Dec 12, 2011
4,656
With 164K I went ahead and replaced the fluid and the pan, went with the recommended Dorman with the drain plug. I added some Lucas trans fix a few days back knowing I would be doing this today, which likely knocked off some varnish adding to the not-so-welcome dark fluid. Intervals have bed 30,70,120, and now 164K.

Either case, it has a slight 2-3 flare so I figure the end is near but hopefully it will chug along for awhile. I pulled the passenger side cooler line and attached a 5/16 OD hose which fit snug against the rib for the quick release. I did add a bottle of Lubegard red this time just to give it that little "extra". For those who haven't done this it's easy and here are some pics.

First thing is to get all 4 off the ground, keeping it somewhat level.

100MEDIA_IMAG2240.jpg


Using a small screwdriver or pick, slide the black collar back to reveal the snap ring.

100MEDIA_IMAG2238a.jpg



The snap ring can be pushed out easily with a pick, just be sure to hold on to the other side to prevent flight. Lift one of the ends of the snap ring, not the loop part.

Slide the hose over the flare of the tube and it will stay, no need for a clamp.

100MEDIA_IMAG2245.jpg


I pumped out the fluid until it bubbled and it dumped about 6 quarts or so, let it sit a few minutes and started it again dumping about another quart or so. This way the pan will be near empty making the removal easier.

Was going to use the brass fittings to keep it weighted down but clamping it high was the better alternative given the fact I wasn't using a clear tube.

First dump

100MEDIA_IMAG2249.jpg



At this point I went ahead and removed the pan and filter. I reused the filter seal since the fit was still pretty snug.


Remainder of fluid in pan, so far....no mess.

100MEDIA_IMAG2246.jpg



I used the box it came in to catch the drips, sides work great to keep the breeze from taking fluid all over the driveway.

100MEDIA_IMAG2247.jpg


I laid the gasket out and pushed in 4 bolts to hold it in place. The right rear corner bolt leave out since the bracket holds the pan close to the valvebody.

100MEDIA_IMAG2248.jpg


I refilled the dipstick tube with 1 gallon of ATF (Maxlife) then restarted until the flow stopped. Did this again and on the 3rd drain I started seeing cleaner fluid. Grand total in bucket was about 14 quarts....four 1-gal jugs is what you will need having about 2 qts left over.


100MEDIA_IMAG2250.jpg


I could have easily pushed another 3-4 slightly dirty quarts out but this will work. Next time I will get the quick-disconnect tube and use the other side so I can drain the cooler but either way will work fine.

Not really the shade of pink I was looking for today... but I can say on the dipstick it appears much lighter, even on a white rag. Nonetheless that's some dark fluid and I will be searching for some rebuild kits sooner than later.
 

Mark20

Member
Dec 6, 2011
1,630
A full flush is on my list though I'm not sure if I want to do your full drain or fill while draining.

Recommendations?

Anyone in suburban Philly want to give me a hand when the weather warms up? For some reason I'm a little nervous about doing this job.
 

gmcman

Original poster
Member
Dec 12, 2011
4,656
At the very least, changing out all the fluid via the cooler line is easier than an oil change. Changing the filter is more involved but definately recommended.

You could always get 4 gallons of ATF and take it somewhere and have it flushed, along with a filter change, saving some of the shop costs.
 

Mark20

Member
Dec 6, 2011
1,630
Though I've never done it, dropping the pan and replacing the filter doesn't bother me as much. Its pulling that cooler line and wither run until it sputters or fill as its coming out.
 

WillyGood

Member
Jan 31, 2012
42
I'm kinda nervous about doing this also. Some one told me once that if the tranny hasn't been flushed in a very long time that you could do more harm then good? that doesn't sound right to me, maybe you guys know? I got the truck at 60k and almost have 100k on it now. Not sure if it's ever been done.

Mark you live in north east Philly?
 

03envoy

Member
Dec 25, 2011
537
What the advantages of the Dorman? The drain plug for easy changes?
 

Mark20

Member
Dec 6, 2011
1,630
WillyGood said:
I'm kinda nervous about doing this also. Some one told me once that if the tranny hasn't been flushed in a very long time that you could do more harm then good? that doesn't sound right to me, maybe you guys know? I got the truck at 60k and almost have 100k on it now. Not sure if it's ever been done.

Mark you live in north east Philly?

Basically but over the city line and into Bucks county.

I've seen the same thing about don't change the tranny fluid if its never been flushed and has a lot of miles. Somewhere I remember reading that 40 or more years ago that might have been good advice but tranny's and fluids have come a long way. Mine was service at 55K but the trailer I towed was hard on it and I want to do a full flush by 75K.
 

gmcman

Original poster
Member
Dec 12, 2011
4,656
Mark20 said:
Its pulling that cooler line and wither run until it sputters or fill as its coming out.

The line I removed literally pulls out and has a seal inside the cooler fitting so nothing to fall out when you pull the line.

Remove the spring clip, pull the line out and attach a hose. Start the engine and when it starts to give a sputter shut it down, no real danger of damage since you are not driving it. It will not lose it's prime if that's what you are worried about..takes only a couple seconds to restore flow.

Secure the drain hose similiar to what I did as it does have some pressure behind it, just enough to flip the hose out and make a real mess of everything.

I haven't seen any hard evidence on using the other line to draw fresh fluid, I would have to assue that's not a good way to flush fom a price standpoint. The pump pulls from the filter and I want to believe that if you draw fresh from the other line, that it would get too mixed up with the old fluid before it was pumped out. This way the pump pulls the old fluid out of the pan, then you fill fresh fluid. Second start it draws only fresh fluid and pushes more old fluid out.
Both ways would surely get most of the old fluid out, but drawing from the other line would likely take alot more fluid to acomplish the same task. Correct me if i'm wrong.
 

Busterbrown

Member
Dec 4, 2011
253
WillyGood said:
I'm kinda nervous about doing this also. Some one told me once that if the tranny hasn't been flushed in a very long time that you could do more harm then good? that doesn't sound right to me, maybe you guys know? I got the truck at 60k and almost have 100k on it now. Not sure if it's ever been done.

GM's recommended service interval for a trans fluid change under normal driving conditions is 100K miles. So, you should be fine. The thought behind high mileage changes is that the additives in the newer fluids will loosen up undesirable crud, causing a mechnical failure. At your mileage, I don't think you'll have an issue.
 

gmcman

Original poster
Member
Dec 12, 2011
4,656
03envoy said:
What the advantages of the Dorman? The drain plug for easy changes?

Pretty much.

Alot easier to drain the pan first then remove. If you want to keep the fluid fresh you can always drain the pan and top off the 4 quarts or so at more frequent intervals then change the filter at the 30-40K mark.

Since I have the pan installed it's definately mine. If I had to do it all over again, I wouldn't get the pan since the cooler line drain is so easy and gets a whole lot more fluid out.
 

Mark20

Member
Dec 6, 2011
1,630
Your description gives me a lot more confidence.
 

WillyGood

Member
Jan 31, 2012
42
Mark20 said:
Basically but over the city line and into Bucks county.

I've seen the same thing about don't change the tranny fluid if its never been flushed and has a lot of miles. Somewhere I remember reading that 40 or more years ago that might have been good advice but tranny's and fluids have come a long way. Mine was service at 55K but the trailer I towed was hard on it and I want to do a full flush by 75K.

I moved further north about two years ago, But before that I lived on the boulevard and Rhawn for about four years. You ever hit up Chicky's and Pete's? whats your favorite cheasesteak joint?

Yeah I'm gonna do the flush as soon as the weather warms. Then rear diff fluid and fuel filter. Then I should pretty much be done with the fluids and filters for awhile and can focus on funner things i.e sound system, exhaust.
 

Tofer76

Member
Dec 8, 2011
148
where u get the new pan? and how much did it cost you? where exactly did you put in a disconnect at and why ?
 

gmcman

Original poster
Member
Dec 12, 2011
4,656
tbuckalew14 said:
Not sure where the OP got his pan from...but I bought the same one from amazon.com for like 36 bucks shipped.

That's where I bought it.

Tofer76 said:
where exactly did you put in a disconnect at and why ?

The quick-disconnect fittings are factory, I didn't install anything. I just pulled the line and attached the hose.
 

Mark20

Member
Dec 6, 2011
1,630
There are a lot of things the manufacturers are doing to speed up assembly. Unfortunately not all are good for the repair side of things. These tranny cooler attachments are one of the better ideas.

From gmsman's pix I now really understand how the adapter for putting in a tranny cooler works. Something I may tackle but probably won't since the Envoy won't be pulling the camper much if at all.
 

MAY03LT

Member
Nov 18, 2011
3,412
Delmarva
gmcman said:
I haven't seen any hard evidence on using the other line to draw fresh fluid, I would have to assue that's not a good way to flush fom a price standpoint. The pump pulls from the filter and I want to believe that if you draw fresh from the other line, that it would get too mixed up with the old fluid before it was pumped out. This way the pump pulls the old fluid out of the pan, then you fill fresh fluid. Second start it draws only fresh fluid and pushes more old fluid out.
Both ways would surely get most of the old fluid out, but drawing from the other line would likely take alot more fluid to acomplish the same task. Correct me if i'm wrong.

gmcman said:

I'd say you're right about the price. It takes almost 4 gallons to flush the system completely. My work has one of those fancy trans flush machines. One hose connects to the line as shown here, the other goes into the cooler via an adapter (I told you it was fancy!). All it does is uses the pump to push the old crap out while sucking the new stuff in. It uses 14qts of fluid, and I can say that the fluid afterwards is immaculately clean.

Currently I'm looking for an inexpensive fitting that would fit into the cooler (where the line was removed in the pic) and allow a length of hose to be attached. Then, using (2) 5 gallon buckets, you could flush the entire system in one shot, including the cooler.
 

gmcman

Original poster
Member
Dec 12, 2011
4,656
MAY03LT said:
Currently I'm looking for an inexpensive fitting that would fit into the cooler (where the line was removed in the pic) and allow a length of hose to be attached. Then, using (2) 5 gallon buckets, you could flush the entire system in one shot, including the cooler.



Lint posted this in another thread: Fitting, 2000-up, some GM applications Fitting kits Makco Transmission Parts It's a Hayden 397 fitting.

Pricey little booger but it's what you need.

Also here: Hayden 397 - Transmission Line Fitting Kit | O'Reilly Auto Parts

Hayden Automotive 397 - Hayden Transmission Line Adapter Fittings - Overview - SummitRacing.com
 

MAY03LT

Member
Nov 18, 2011
3,412
Delmarva
gmcman said:
Lint posted this in another thread....Pricey little booger but it's what you need.

Sweet! Thank you sir.:thumbsup:
 

gmcman

Original poster
Member
Dec 12, 2011
4,656
MAY03LT said:
Sweet! Thank you sir.:thumbsup:

Anytime.

Just remember to use that fitting on the drivers side. Trans fluid flows from pass side to driver side.
 

tbuckalew14

Member
Nov 20, 2011
380
Did this on sunday. I thought it went pretty smoothly until I started driving it to work the next day. Now it's slipping and the rpms get a little erratic in the 45-50 range when i'm coasting. Almost like it's shifting back and forth between gears. Had it flushed at 50k with no ill results...i'm at 101k now.
 

gmcman

Original poster
Member
Dec 12, 2011
4,656
Did you replace the filter, and if so did they match up?

How did you verify the fluid level? Needs to be with trans hot, level ground, engine running and in park.
 

tbuckalew14

Member
Nov 20, 2011
380
gmcman said:
Did you replace the filter, and if so did they match up?

How did you verify the fluid level? Needs to be with trans hot, level ground, engine running and in park.

Bought a filter kit off amazon.com. ACDelco 24208576. Lowered truck back down, let engine run a little. Checked the trans dipstick, wasn't even on the cold mark. Poured in about another quart to a quart and a half. All in all about somewhere around 13 quarts.
 

gmcman

Original poster
Member
Dec 12, 2011
4,656
Sounds like the fluid is low or the pump isn't drawing fluid. Almost certain you need a filter for a deep pan.
 

tbuckalew14

Member
Nov 20, 2011
380
gmcman said:
Sounds like the fluid is low or the pump isn't drawing fluid. Almost certain you need a filter for a deep pan.

AC DELCO AUTOMATIC TRANSMISSION FLUID FILTER KIT -- A high quality, OE replacement automatic transmission fluid filter kit; For use with 76.6 mm deep pan; Replaces OE number 24208576.

Bought a deep pan filter. No leaks anywhere either.

I'll double check fluid level again when I go out later.
 

gmcman

Original poster
Member
Dec 12, 2011
4,656
That's the one, I am unable to check where I'm at so just wanna be sure. make sure the fluid level is correct so you don't smoke the transmission.
 

am-radio

Member
Apr 24, 2012
178
I like the idea of disconnecting the transmission cooler lines at the radiator and running the vehicle until it pumps out all the old tranny fluid. Do this a few times until clear, then drop the tranny pan and change the filter. A much better ratio of fresh ATF vs old ATF. Is there any chance of wrecking the torque converter or transmission running it dry for a few seconds doing this method?
 

Busterbrown

Member
Dec 4, 2011
253
am-radio said:
I like the idea of disconnecting the transmission cooler lines at the radiator and running the vehicle until it pumps out all the old tranny fluid. Do this a few times until clear, then drop the tranny pan and change the filter. A much better ratio of fresh ATF vs old ATF. Is there any chance of wrecking the torque converter or transmission running it dry for a few seconds doing this method?

When the fluid stream from the cooler line begins to sputter, immediately turn the ignition off. The mechanics should be fine as the tranny wasn't engaged in any gear during the process. Between the pan and the flush, I think I consolidated 10.5 quarts. IIRC, 11 quarts is the initial fill capacity. Not bad for a "complete" fluid swap.
 

WarGawd

Member
Sep 2, 2012
468
gmcman said:

Here's another possibilty, given that May03LT seems to work on other peoples vehicles, not just his own, same price:

Life Automotive Products - Smart Blend Synthetics, Trans Flush, ATF Products
 

xj2202009

Member
Mar 27, 2012
105
does anyone knows what's the difference between these two? going to attempt this today.



A/Trans Filter Kit
Part Number: ATP 18567 napa says this is has a better seal.
Product Line: NAPA Automatic Transmission Parts
IMPORTANT INFO: w/ Deep Pan,w/ Stepped Bottom Pan) & w/ 1 1/4" Flat Filter,4-1/8" Tube
Add to Compare
$24.99 /ea
http://napaonline.com/Catalog/CatalogItemDetail.aspx?R=ATP18567_0259786295

http://napaonline.com/Catalog/CatalogItemDetail.aspx?R=ATP19750_0259786303
Part Number: ATP 19750
Product Line: NAPA Automatic Transmission Parts
IMPORTANT INFO: w/ Deep Pan,w/ Stepped Bottom Pan) & w/ 1 1/4" Flat Filter,4-1/8" Tube
 

rmsg0040

Member
Dec 10, 2011
285
also torque the pan bolts to 120 in lbs or it might drip

Right now I am dripping, hopefully I can pick up a 1/4 torque wrench soon.

Wix filter and dorman pan I got from rockauto
 

Wooluf1952

Member
Nov 20, 2011
2,663
Milwaukee, Wisconsin
xj2202009 said:
does anyone knows the hose diameter to attach to draining hose?


The first post says 5/16" OD. That would be about 3/16" ID. That seems small. Maybe 5/16" ID?
 

WarGawd

Member
Sep 2, 2012
468
After eyeballing the cooler line in preparation for this, I bought 10 ft of 1/2" ID clear tubing along with a little gear clamp for about $8 at Canadian Tire - that way if 1/2" was too small I could stretch the end open for a tight fit and if it was a bit too big the clamp would cover me. (FYI while looking for something else, I spotted a thread on the OS that states the cooler lines are 3/8", I assume that's ID so 1/2" ID / 5/16 OD drain tubing will probably be workable)

BUT I noticed tonite when I looked at the cooler inlet line on the passenger side of mine, it does NOT look like the pics 2 & 3 in gmcman's other thread here. Where his seems to go up towards the top of the rad and is all steel in the pics, mine heads down about 2" and goes into a rubber hose with a gear clamp securing it. It was dark and wet so I didn't have time or inclination to follow it, but I suspect I may have an additional external cooler tucked away somewhere that I hadn't known about. Need to look at this better tomorrow. Flush will get done Monday because running Seafoam TransTune in it for tonite has made a HUGE difference in the color of the fluid - what was a light brown tinge at the beginning of the night is really dark brown & sludgy looking after 100km.
 

gmcman

Original poster
Member
Dec 12, 2011
4,656
Wooluf1952 said:
The first post says 5/16" OD. That would be about 3/16" ID. That seems small. Maybe 5/16" ID?

Yeah, I believe I was referring to the cooler line's OD.

You are correct, I used 5/16" ID tubing to slip over the cooler line.
 

WarGawd

Member
Sep 2, 2012
468
WarGawd said:
...I suspect I may have an additional external cooler tucked away somewhere that I hadn't known about. Need to look at this better tomorrow.

Sure enough, there's an external cooler installed. Looks like they cut some of the plastic on the bottom of the shroud on the pass. side to shove it up in there. Couldn't tell how or even IF it's secured - it leans forward away from the rad at the top, and of course that space has collected a fair bit of leaf and seed pod debris limiting the airflow I'm sure. I think the fact that the two lines are a bit more accessible and have a little nut driven gear clamp offers me a couple more options for getting a better flush. I'll update this tomorrow if I learn anything helpful.
 

WarGawd

Member
Sep 2, 2012
468
WarGawd said:
Sure enough, there's an external cooler installed. Looks like they cut some of the plastic on the bottom of the shroud on the pass. side to shove it up in there. Couldn't tell how or even IF it's secured - it leans forward away from the rad at the top, and of course that space has collected a fair bit of leaf and seed pod debris limiting the airflow I'm sure. I think the fact that the two lines are a bit more accessible and have a little nut driven gear clamp offers me a couple more options for getting a better flush. I'll update this tomorrow if I learn anything helpful.

Well, it was a PITA but it`s done!

I decided to skip playing with the collar and clamp at the radiator joint, and use the lines in & out of the external cooler instead. A couple different hose configurations allowed me to use my fluid pump to seperately flush the old fluid out of each of the coolers. Used ~ 2-3 liters for that. I confirmed there is no suction on the return line side, so future attempts to draw in flesh fluid while pumping out the old won't work.

Had to skip the new metal/rubber collar that the filter neck inserts into - could NOT get the old one out and it seemed in good shape, fit the new filter neck tightly, so rather than risk damaging it I didn't try too hard. There must be a trick to it, wish I had paid better attention to that part in other threads and articles.

After a couple of cycles of putting in new fluid & running engine to pump out old, I still couldn't see much difference in fluid color through the clear waste hose - the old fluid kinda stained the hose brownish and made it hard to tell the difference. As a result I prob used more fluid than I needed to but oh well. Will cut the 10' hose in half next time, and change out the hose after a couple cycles.

After verifying new fluid was being pushed out, dropped the pan, gasket came off easy, cleaned thorougly, wear material fine sludge was present but not awful. Cleaned it all, reassembled using thin bead of Permatex Ultra Black RTV to secure gasket in place.

All that was done in reasonable time, but when I tried to get the last line reconnected from tranny to ext. cooler, it took me over an hour of fighting to get the damn rubber hose to slip over the line flare. Awkward angle, little clearance, sun now shining right in my face and under pressure to clean up and get to work. Had to split the end of the hose and bend the steel line a bit to get it done. Double clamped this one on each side of the flare just to be sure there's no leaks down the road.

Not trying to hijack this thread, if anybody wants, I did a quick sketch of the setup and can do a quickie step-by step for flushing the coolers - lemme know and I'll put it in a new thread.
 

Sparky

Member
Dec 4, 2011
12,927
Pretty common for that filter seal to not want to budge and also be just fine reusing it.
 

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