4T80-E ATF color 9 months after exchange

mtflight · #1 (**permalink**) 11-20-05, 02:08 AM

So when I purchased the Eldo 9 months ago, first thing I did was a coolant drain and fill, fixed broken tie-rod ends, and had the transmission fluid changed.

After replacing my radiator a few weeks ago, I go to look at the transmission fluid and I thought I'd extract a quart and put it in a container to examine it for traces of coolant. I extracted a quart with a turkey baster, and replaced it with a fresh quart.

The fresh quart is red and clear. The quart I took out was reddish-brown and clear (not contaminated with coolant).

They charged me $500 to change the ATF fluid and also to replace the two tie-rod-ends ($130 of that for an alignment). Needless to say I felt "raped" and never went back.

Is it normal for the fluid to turn reddish brown in 9 months? or did they NOT do the fluid exchange? Is there a way to know? Is it easy to do the fluid exchange myself? Where should I take it?

Tranny is shifting fine, and working flawlessly as usual.

Krashed989 · #2 (**permalink**) 11-20-05, 02:14 AM

It is truely impossible to change all of the fluid the way most shops do.

Here, this page tells how it should be done:
http://www.cadillacforums.com/cadill...tml#transflush

mtflight · #3 (**permalink**) 11-20-05, 02:21 AM

Quote:

Originally Posted by Krashed989

It is truely impossible to change all of the fluid the way most shops do.

Here, this page tells how it should be done:
http://www.cadillacforums.com/cadill...tml#transflush

I know what you mean, here are the fluid capacities for the 4T80-E:

Bottom Pan Removal (requires drain plug removal) 11qt
- (This is what the shop was paid to do)
Complete Overhaul 12.6 qt
Dry 15 qt

But back to my concern... do u think it turned brown so soon? Other than the ocasional WOT, I don't tow or do anything outrageous.

On the dipstick, the fluid has a reddish hue, but when poured into a clear container--it's brown with a red overtone. By contrast the new stuff is clear red.

Krashed989 · #4 (**permalink**) 11-20-05, 02:33 AM

They probably didn't see the drain plug, or thought it was an important bolt to hold something else in place. Although I'm sure the place you went to will say otherwise, just to get more money out of you. It's this very thing that makes me weary about handing my keys over for someone else to fix my car. You never know how lazy the person is that day, or what mistakes they may be trying to cover up.

If it's changing color, I would change the fluid, properly this time. The old cliche that goes well here is, if you want something done right, do it yourself.

zonie77 · #5 (**permalink**) 11-20-05, 11:16 AM

If you would have changed it yourself you would have noticed a blackish film on the internal trans. Sometimes you barely notice it until you wipe something off. I guess it's similar to sludge buildup in an engine. Fresh fluid cleans most of this off by disolving it in the fluid. That gets the fluid slightly dirty very quickly.

I guess if you changed trans fluid every 20-30k the fluid would stay real clean. That's more than necessary though. I think the change in color is normal and not something to worry about. As long as it smells OK.

mtflight · #6 (**permalink**) 11-20-05, 12:10 PM

Quote:

Originally Posted by zonie77

If you would have changed it yourself you would have noticed a blackish film on the internal trans. Sometimes you barely notice it until you wipe something off. I guess it's similar to sludge buildup in an engine. Fresh fluid cleans most of this off by disolving it in the fluid. That gets the fluid slightly dirty very quickly.

I guess if you changed trans fluid every 20-30k the fluid would stay real clean. That's more than necessary though. I think the change in color is normal and not something to worry about. As long as it smells OK.

That could explain it. The smell is not too different from the fresh ATF to the one I took out. I hope I did some good, by putting in a new quart (kind of like replenishing the anti-wear additives when we add a quart to the Northstar crankcase?).

How much does it run to do the fluid exchange myself? I know there's a filter involved and a new gasket, am I correct? I always hear about the hidden drain plug... yet have obviously not seen a picture of that and the service manual doesn't show it. Being that it would be the first time I look at it--what are the odds of finding it?

I like the idea of pouring in fluid until it comes out clean on the bucket (the technical section posting). How many quarts would that likely be? 20?

**Jesda** · #7 (**permalink**) 11-20-05, 12:35 PM

Bob's post on tranny flushes is full of speculative BS.

Go to a shop that uses BG flush equipment.
http://www.bgprod.com/products/transmission.html
Have your Caddy hooked up to the machine. This will also remove the fluid in the torque converter.

zonie77 · #8 (**permalink**) 11-20-05, 01:27 PM

There is a lot of debate on flushing as opposed to draining. Our old friend did not recommend it and there is considerable evidence that supports him. Since you've had yours changed you don't have a lot of dirt/sludge in it. One of the concerns is the backwards flow loosening the sludge.

The trans usually has a rubber, reusable gasket. If yours has been changed it might be a cork one. The filters are screens that don't get replaced. So the cost of changing it could be just the cost of fluid.

There is a technique of disconnecting a cooling line and extending it into a large bucket or pan. Then starting the car and let the engine pump the fluid out. You refill the pan as this is happening, usually by shutting off the engine as the flow stops. I have done this and it seems to work well. At idle the fluid comes out fairly fast but not at high pressure.

**Ranger** · #9 (**permalink**) 11-20-05, 01:29 PM

Quote:

Originally Posted by mtflight

How much does it run to do the fluid exchange myself? I know there's a filter involved and a new gasket, am I correct? I always hear about the hidden drain plug... yet have obviously not seen a picture of that and the service manual doesn't show it. Being that it would be the first time I look at it--what are the odds of finding it?

It is messy but the cost is nothing more than a case of trans fluid. There are no filters in the pan. Just two screens that are cleanable (if needed), and reusable as well as the gasket.

The hidden drain plug is directly under the side cover. I can't recall exactly but I think it is between the two screens, or at least very close to them.

Flush at your own risk. I wouldn't do it.