Trans overfilled
Thread Starter
Intermediate
Joined: Nov 2015
Posts: 48
Likes: 6
Trans overfilled
I bought a '94 coupe last fall and stored it all winter and now I'm getting ready to put it on the road. I bought it from a GM dealer with "factory trained" techs. So, I had it shipped from out of state and when I get it home I find it's 4 quarts overfilled with oil. OK took care of that. Now the trans fluid is 2 1/2 " above the filled line when cold. I think it's probably 2 quarts or more overfilled. So, without dropping the pan how do I get it out? Would one of those cheap gas suction things work?
Racer
Joined: Aug 2014
Posts: 338
Likes: 79
From: STATE OF CONFUSION IN THE COUNTY OF L.A
you disconnect the lower transmission cooler line from the radiator
start the engine and fill a 2 litre soda bottle with fluid try taking out a qt first and keep and eye on the level as you pump it out 15 -20 seoconds
should get a qt out
You may need some sections of hose to slip over the cooler line
this trans flush procedure has been discussed here at length use the search function if it what I'm describing dosen't make sense to you
start the engine and fill a 2 litre soda bottle with fluid try taking out a qt first and keep and eye on the level as you pump it out 15 -20 seoconds
should get a qt out
You may need some sections of hose to slip over the cooler line
this trans flush procedure has been discussed here at length use the search function if it what I'm describing dosen't make sense to you
Le Mans Master
Joined: Jun 2009
Posts: 6,528
Likes: 752
From: South Dakota
I have used a suction on a couple cars and it wouldn't work on a few. I don't know on a '94 Corvette.
However, I wouldn't bother trying. If these "factory trained" techs couldn't fill it right, then do you think they even used the right fluid? I would think this is a great time to drop the trans oil pan and replace the filter and put in new fluid so you know what you are starting with.
Good luck.
However, I wouldn't bother trying. If these "factory trained" techs couldn't fill it right, then do you think they even used the right fluid? I would think this is a great time to drop the trans oil pan and replace the filter and put in new fluid so you know what you are starting with.
Good luck.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
That's about right. When the engine is running the trans pump fills up the torque converter and the trans cooler, so the level will drop.
You need to check the fluid level when the trans is HOT and the engine is running. After driving to get the trans hot I usually wait a minute or so for everything to settle down before checking the level.
You need to check the fluid level when the trans is HOT and the engine is running. After driving to get the trans hot I usually wait a minute or so for everything to settle down before checking the level.
Last edited by Cliff Harris; Mar 16, 2016 at 12:30 AM.
Race Director
Joined: Oct 2008
Posts: 17,982
Likes: 1,074
From: Lansing MI
Drop the pan or use some sort of suction device.
I am reasonably confident the cooler lines at the radiator are part of the lubrication circuit in your transmission. Personally I wouldn't interrupt the flow of that oil, even though it may seem easier.
I am reasonably confident the cooler lines at the radiator are part of the lubrication circuit in your transmission. Personally I wouldn't interrupt the flow of that oil, even though it may seem easier.
Team Owner
Joined: Jul 2004
Posts: 28,471
Likes: 3,290
From: Hartford WI
I know on my Powerstroke, the trans builder who effectively warranties his transmissions for life does it that way and did it in front of me one time and we didn't see any bubbles in the clear tube. We dumped the appropriate amount of fluid in, overfilled by a few (maybe 4 qt), start it and when about a gallon fills up, we shut down. Overfill again, run engine and shut down. After that, we top off. We did this because there was no drain plug in the TC and we wanted to clean out that old fluid after 30K
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
I have used a suction on a couple cars and it wouldn't work on a few. I don't know on a '94 Corvette.
However, I wouldn't bother trying. If these "factory trained" techs couldn't fill it right, then do you think they even used the right fluid? I would think this is a great time to drop the trans oil pan and replace the filter and put in new fluid so you know what you are starting with.
Good luck.
However, I wouldn't bother trying. If these "factory trained" techs couldn't fill it right, then do you think they even used the right fluid? I would think this is a great time to drop the trans oil pan and replace the filter and put in new fluid so you know what you are starting with.
Good luck.
with this 100%...Once I find something someone has screwed up on a car, then any work they have done becomes suspect....
?...WW.
.
.
Last edited by WW7; Mar 16, 2016 at 10:59 AM.
Team Owner
Joined: Jul 2004
Posts: 28,471
Likes: 3,290
From: Hartford WI
I usually have bad luck leaving the car there for you to fix. Even if they say "no standing by the car", I sit far away enough in the shop with binoculars to see what is going on. I have trust issues.
Race Director
Joined: Oct 2008
Posts: 17,982
Likes: 1,074
From: Lansing MI
I thought the oil goes from the trans to the trans cooler and back? The return line seems higher than the oil pan which is where it sucks the fluid out of via the filter which is almost at the bottom. So while it is part of the circuit, what would it affect, really? I know on my Powerstroke, the trans builder who effectively warranties his transmissions for life does it that way and did it in front of me one time and we didn't see any bubbles in the clear tube. We dumped the appropriate amount of fluid in, overfilled by a few (maybe 4 qt), start it and when about a gallon fills up, we shut down. Overfill again, run engine and shut down. After that, we top off. We did this because there was no drain plug in the TC and we wanted to clean out that old fluid after 30K
I know on my Powerstroke, the trans builder who effectively warranties his transmissions for life does it that way and did it in front of me one time and we didn't see any bubbles in the clear tube. We dumped the appropriate amount of fluid in, overfilled by a few (maybe 4 qt), start it and when about a gallon fills up, we shut down. Overfill again, run engine and shut down. After that, we top off. We did this because there was no drain plug in the TC and we wanted to clean out that old fluid after 30KI just don't do things that way. To each their own.
Team Owner
Joined: Jul 2004
Posts: 28,471
Likes: 3,290
From: Hartford WI
However, would it hurt if you had an assistant who would help you shut down after a quart or two? I suppose the safest way is to do what I have done which is use my Topsider to suck it out. Unfortunately many don't have shop air and the Topsider