Trans flush on a GM 3.8

purplepickup · September 28, 2005, 03:48:14 PM

I want to do a poor man's tranny flush on my Buick and if I'm thinking right I can drop the pan, change the filter, put it back together, fill the pan with fluid, then pull the return line (after it goes thru the radiator), start the car and add new fluid while it's pumping out old fluid til it starts pumping new fluid. Is that the way to do it? Should I do anything different? Which is the return line? :?

1FATGMC · September 28, 2005, 04:36:47 PM

Quote from: "purplepickup"I want to do a poor man's tranny flush on my Buick and if I'm thinking right I can drop the pan, change the filter, put it back together, fill the pan with fluid, then pull the return line (after it goes thru the radiator), start the car and add new fluid while it's pumping out old fluid til it starts pumping new fluid. Is that the way to do it? Should I do anything different? Which is the return line? :?

George I did it that way on 1FATGMC a couple years ago with the 700R4. I don't remember having time to put fluid in while it was running. It went pretty fast. As I remember when the old dirty fluid pumped out of the converter it kind of burped right before the clean fluid started flowing. I shut it off and filled the transmission and then again at the very end to check things.

The return line is the one where the fluid is going back to the transmission

. I know, not funny

. Tony will have to handle that.

c ya, Sum

purplepickup · September 28, 2005, 05:09:32 PM

Quote from: "1FATGMC"The return line is the one where the fluid is going back to the transmission .
c ya, Sum

Gosh, I should have known that :|

34ford · September 28, 2005, 06:22:54 PM

I'd like to throw in a question in here for Tony to about changing fluids on a high mileage vehicle. Was thinking of doing the same on my 1997 Explorer which has 140,000 miles. It's never had the fluid changed or the filter, I know I should have did it long ago. So, does putting in new fluid like George wants to do cause any problems like blowing out seals or anything? Thought others might want to know the same thing

thanks bob

Dave · September 28, 2005, 07:05:20 PM

Quote from: "34ford"I'd like to throw in a question in here for Tony to about changing fluids on a high mileage vehicle. Was thinking of doing the same on my 1997 Explorer which has 140,000 miles. It's never had the fluid changed or the filter, I know I should have did it long ago. So, does putting in new fluid like George wants to do cause any problems like blowing out seals or anything? Thought others might want to know the same thing

thanks bob

I did it once on a 100,000 mile tranny. Heres the deal or what I was told after it wouldnt go any mo.... Trans fluid is a very hi detergent oil (cleans well) It can after a fluid change clean all the old worn seals to the extent that now they have leakage and it dont go no mo? Take it for what its worth but ive had a lot of used cars sincw then and if the tranny fluid wasnt changed before i didnt do it...
Dave

1FATGMC · September 28, 2005, 07:43:32 PM

Quote from: "N8DC"
Quote from: "34ford"I'd like to throw in a question in here for Tony to about changing fluids on a high mileage vehicle. Was thinking of doing the same on my 1997 Explorer which has 140,000 miles. It's never had the fluid changed or the filter, I know I should have did it long ago. So, does putting in new fluid like George wants to do cause any problems like blowing out seals or anything? Thought others might want to know the same thing

thanks bob

I did it once on a 100,000 mile tranny. Heres the deal or what I was told after it wouldnt go any mo.... Trans fluid is a very hi detergent oil (cleans well) It can after a fluid change clean all the old worn seals to the extent that now they have leakage and it dont go no mo? Take it for what its worth but ive had a lot of used cars sincw then and if the tranny fluid wasnt changed before i didnt do it...
Dave

I'd second the no change on a high mileage car. I did that to the '78 Buick we bought a couple years ago with 135,000 miles on it. Tranny blew up a couple days later in Ok

.

Thanks to WZJUNK and Hooley I was on my way again a couple days later with a different transmission that is still working. I don't think the fluid was ever changed before that.

c ya, Sum

Crosley.In.AZ · September 28, 2005, 08:13:22 PM

changing fluid on a high mileage tranny that had NO service is usually a bad thing.

I have no idea which tranny line is the return on the FWD car.

It is a FWD car?

pull the top line from the radiator... pull a hose on the end to a container...

start the motor for a second. Clean the mess up.

tomslik · September 28, 2005, 08:32:25 PM

Quote from: "Crosley"changing fluid on a high mileage tranny that had NO service is usually a bad thing.

I have no idea which tranny line is the return on the FWD car.

It is a FWD car?

pull the top line from the radiator... pull a hose on the end to a container...

start the motor for a second. Clean the mess up.

jeezzzz, you think a proffesional would tell ya the correct way..

hook 2 hoses up to the car and put 'em BOTH in the bucket.

kick the bucket over, THEN clean up the mess...

Crosley.In.AZ · September 28, 2005, 10:49:42 PM

Quote from: "tomslik"
Quote from: "Crosley"changing fluid on a high mileage tranny that had NO service is usually a bad thing.

I have no idea which tranny line is the return on the FWD car.

It is a FWD car?

pull the top line from the radiator... pull a hose on the end to a container...

start the motor for a second. Clean the mess up.

jeezzzz, you think a proffesional would tell ya the correct way..

hook 2 hoses up to the car and put 'em BOTH in the bucket.

kick the bucket over, THEN clean up the mess...

I forgot tomslik was a fumble-fart

purplepickup · September 29, 2005, 03:40:30 PM

Ok, you guys got me a little gun shy about flushing this. It's got 95K on it and I've changed the filter and fluid in the pan at 35K and 75K. I'm thinking the type of flush that does damage is when they force fluid thru the tranny instead of letting the pump push it thru like I want to do. I could see where the forced method would stir up things that you don't want stirred.

When I pulled the pan and checked inside the filter there wasn't any foreign junk at all except for a little gray dust stuck to the magnet in the pan. The fluid isn't real fresh looking but it doesn't look or smell burnt either. I just can't see that leaving old fluid in there is better than changing all of it. I guess I'll pull a line and do the flush and hope it does good instead of bad.

tomslik · September 29, 2005, 03:53:09 PM

[

Quotefumble-fart

1st ya call me a "doll" and now a fumble-fart?

ya worry me

1FATGMC · September 29, 2005, 04:37:26 PM

Quote from: "purplepickup"Ok, you guys got me a little gun shy about flushing this. It's got 95K on it and I've changed the filter and fluid in the pan at 35K and 75K. I'm thinking the type of flush that does damage is when they force fluid thru the tranny instead of letting the pump push it thru like I want to do. I could see where the forced method would stir up things that you don't want stirred.

When I pulled the pan and checked inside the filter there wasn't any foreign junk at all except for a little gray dust stuck to the magnet in the pan. The fluid isn't real fresh looking but it doesn't look or smell burnt either. I just can't see that leaving old fluid in there is better than changing all of it. I guess I'll pull a line and do the flush and hope it does good instead of bad.

If you have changed the fluid before (even though it wasn't a complete change) I would go ahead with what you have planned. In my case I don't think the fluid had ever been changed in 135,000 miles and it looked nasty.

c ya, Sum

purplepickup · September 29, 2005, 08:17:22 PM

Tony was right...the return line is the one on top of the radiator. I threaded another line into the fitting and started the car. I actually was pouring oil in faster than it was being pumped out. When the fluid started to run clear I was about 2 quarts overfull so I just ran it til the extra ran out. Piece of cake...no mess at all

I took it out for a drive and it feels great. Hope it stays that way.

Crosley.In.AZ · September 29, 2005, 11:24:01 PM

Quote from: "purplepickup"Tony was right...the return line is the one on top of the radiator.

hmmmmmmm, seems like a professional tranny guy may have known that. Somebody tell that to ol fumble fart tomslik.

He is a living doll

George , did you break open the filter? Often the debris is sucked up into the filter and the pan is clean

purplepickup · September 30, 2005, 09:05:44 AM

Quote from: "Crosley"George , did you break open the filter? Often the debris is sucked up into the filter and the pan is clean

I did open it and there was black junk in there but not chunks of anything. The goook on the left hasn't got any chunks in it except for a couple pieces of the filter shell that fell in when I broke it. I touched a spot that looked like a piece of something but it was just sludge. Is that amount of sludge in the filter normal? There wasn't that much in the pan. It seems like the last filter change was about 25K ago.