leaking problem...need opinions
Thread Starter
Instructor
Joined: Jun 2003
Posts: 158
Likes: 0
From: Salt Lake city Utah
leaking problem...need opinions
I have a 99 c5 with about 70k miles, it has been sitting in a garage about 3 months, one day i went out there and noticed about a quart of transmission fluid on the ground, i asked a person at the dealership their opinion and they said not to be too concerned and that sometimes the torque converter drains into the transmission and it overflows, i dont know how true that is, but he said to take it for a spin and see how things go
any opinions on this would greatly help, the fluid appeared to be leaking somewhere towards the rear, close to the rear diff
any help would be appreciated
any opinions on this would greatly help, the fluid appeared to be leaking somewhere towards the rear, close to the rear diff
any help would be appreciated
Drifting
Joined: Mar 2005
Posts: 1,737
Likes: 0
From: Northern VA
I'm guessing you dont know what a qt. of atf or gear oil spilled looks like....
It wouldn't just be under the car... it would be everywhere.
Trans fluid will be red, and gear oil will be very dark in comparison.
Take a paper towel and wipe - see what color it is.
It wouldn't just be under the car... it would be everywhere.
Trans fluid will be red, and gear oil will be very dark in comparison.
Take a paper towel and wipe - see what color it is.
Thread Starter
Instructor
Joined: Jun 2003
Posts: 158
Likes: 0
From: Salt Lake city Utah
i never said it was just under the car, i noticed it because it was coming out the side of the vehicle, it is red
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Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
I've heard of some leakage from the vent but 2 qts is not a leak its a flood. If it really is that much beware of driving as the transmission could seize. The transmission only holds 4.1 qts so thats half of the fluid gone.
Heres the relevant troubleshooting guide from the T56 Transmission Manual:
Transmission leakage Leakage from other components:
Verify transmission leakage. Thoroughly clean all exposed surfaces, then check for leaks
Vent or breather clogged:
Remove vent tube and clean or replace
Too much or improper lubricant:
Remove fill plug to check for excess, or drain and replace
Loose bolts at sealing faces:
Torque bolts to specifications
Improperly applied sealant:
Separate and thoroughly clean leaking surfaces. Reapply sealant. Replace parts and torque bolts to specifications
Worn or damaged oil seal:
Replace oil seal
Shifter base loose:
Replace shifter assembly
Heres the relevant troubleshooting guide from the T56 Transmission Manual:
Transmission leakage Leakage from other components:
Verify transmission leakage. Thoroughly clean all exposed surfaces, then check for leaks
Vent or breather clogged:
Remove vent tube and clean or replace
Too much or improper lubricant:
Remove fill plug to check for excess, or drain and replace
Loose bolts at sealing faces:
Torque bolts to specifications
Improperly applied sealant:
Separate and thoroughly clean leaking surfaces. Reapply sealant. Replace parts and torque bolts to specifications
Worn or damaged oil seal:
Replace oil seal
Shifter base loose:
Replace shifter assembly
Last edited by DeeGee; Mar 1, 2009 at 04:18 AM.
Racer
Joined: Dec 2005
Posts: 321
Likes: 3
From: bloomington Indiana
I'd say that the rear output shaft seal of the tranny has crapped out. The seal gets "hard" and leaks during the colder weather but is fine during the spring/summer. It's just a bummer to fix when you have to pull the rear suspension & diff.
Look for fluid out of the little rectangular drain hole between the tranny & diff.
Look for fluid out of the little rectangular drain hole between the tranny & diff.
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
Internet guess work is always fun, but not even close to being right a lot of times.
If you have that much fluid on the ground, starting the car in place I would expect you will see more coming from the source without doing damage as long as you don't drive it and don't run it any longer then what is needed to ID the leak location. I would expect you will find it to be trans cooler line connection that has come loose. This is the only place short of a cracked case that I can think of that would allow that much fluid. Bottom line, clean the floor up, run the car long enough to see where it is coming from, and I WOULD NOT drive it until having a good idea of the source..
Has any work been done just before this? What type of driving was being done just before you parked it?
Keep us posted on what you find.
If you have that much fluid on the ground, starting the car in place I would expect you will see more coming from the source without doing damage as long as you don't drive it and don't run it any longer then what is needed to ID the leak location. I would expect you will find it to be trans cooler line connection that has come loose. This is the only place short of a cracked case that I can think of that would allow that much fluid. Bottom line, clean the floor up, run the car long enough to see where it is coming from, and I WOULD NOT drive it until having a good idea of the source..
Has any work been done just before this? What type of driving was being done just before you parked it?
Keep us posted on what you find.
Racer
Joined: Oct 2007
Posts: 470
Likes: 0
From: Saint Cloud Florida
I'd say that the rear output shaft seal of the tranny has crapped out. The seal gets "hard" and leaks during the colder weather but is fine during the spring/summer. It's just a bummer to fix when you have to pull the rear suspension & diff.
Look for fluid out of the little rectangular drain hole between the tranny & diff.
Look for fluid out of the little rectangular drain hole between the tranny & diff.
http://www.cajundude.com/outputshaftseal.htm
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
I dont think his problem is the diff seal if its that amount of fluid. has to be way more serious than that if it really is 2 qts
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,820
From: Charlotte, NC (formerly Endicott, NY)
Here is some info from the Service Manual to help you find the leak:
Fluid Leak Diagnosis
General Method
A fluid dye and black light kit is available from various tool manufacturers.
Pinpoint the leak and trace the leak back to the source. You must determine the cause of the leak in order to repair the leak properly. For example, if you replace a gasket, but the sealing flange is bent, the new gasket will not repair the leak. You must also repair the bent flange. Before you attempt to repair a leak, check for the following conditions, and make repairs as necessary:
Transmission Oil Pan
Case Leak
Leak at the Torque Converter End
Leak at the Vent Pipe or the Fluid Fill Tube
FIGURE Leak Inspection Points(c)
(1)Wiring Harness Pass-through Connector O-Ring Seal(2)Transmission Vent Assembly(3)Converter Housing to Case Joint (Pump to Case Oil Seal)(4)Line Pressure Plug(5)Manual Shaft Seal(6)Case Rear Oil Seal Assembly(7)Torque Converter Assembly(8)Pump to Case Oil Seal(9)Pump Oil Seal Assembly(10)2-4 Servo Cover O-Ring Seal(11)Oil Cooler Pipe Connectors(12)Transmission Case(13)Transmission Oil Pan Gasket
Bill
Fluid Leak Diagnosis
General Method
- Verify that the leak is transmission fluid.
- Thoroughly clean the suspected leak area.
- Operate the vehicle for 24 km (15 mi), or until normal operating temperatures are reached.
- Park the vehicle over clean paper or cardboard.
- Shut OFF the engine.
- Look for fluid spots on the paper.
- Make the necessary repairs.
- Thoroughly clean the suspected leak area with solvent.
- Apply an aerosol type powder, such as foot powder, to the suspected leak area.
- Operate the vehicle for 24 km (15 mi), or until normal operating temperatures are reached.
- Shut OFF the engine.
- Inspect the suspected leak area.
- Trace the leak path through the powder in order to find the source of the leak.
- Make the necessary repairs.
A fluid dye and black light kit is available from various tool manufacturers.
- Follow the manufacturer's instructions in order to determine the amount of dye to use.
- Detect the leak with the black light.
- Make the necessary repairs.
Pinpoint the leak and trace the leak back to the source. You must determine the cause of the leak in order to repair the leak properly. For example, if you replace a gasket, but the sealing flange is bent, the new gasket will not repair the leak. You must also repair the bent flange. Before you attempt to repair a leak, check for the following conditions, and make repairs as necessary:
- Gaskets
- Fluid level/pressure is too high
- Plugged vent or drain-back holes
- Improperly tightened fasteners
- Dirty or damaged threads
- Warped flanges or sealing surface
- Scratches, burrs, or other damage to the sealing surface
- Damaged or worn gasket
- Cracking or porosity of the component
- Improper sealant used, where applicable
- Incorrect gasket
- Seals
- Fluid level/pressure is too high
- Plugged vent or drain-back holes
- Damaged seal bore
- Damaged or worn seal
- Improper installation
- Cracks in component
- Manual or output shaft surface is scratched, nicked, or damaged
- Loose or worn bearing causing excess seal wear
Transmission Oil Pan
• Incorrectly tightened oil pan bolts
• Improperly installed or damaged oil pan gasket
• Damaged oil pan or mounting face
• Incorrect oil pan gasket
• Improperly installed or damaged oil pan gasket
• Damaged oil pan or mounting face
• Incorrect oil pan gasket
Case Leak
• Damaged or missing fill tube seal
• Mislocated fill tube bracket
• Damaged vehicle speed sensor seal
• Damaged manual shaft seal
• Loose or damaged oil cooler connector fittings
• Worn or damaged propeller shaft oil seal
• Loose line pressure pipe plug
• Porous casting warped torque converter housing
• Mislocated fill tube bracket
• Damaged vehicle speed sensor seal
• Damaged manual shaft seal
• Loose or damaged oil cooler connector fittings
• Worn or damaged propeller shaft oil seal
• Loose line pressure pipe plug
• Porous casting warped torque converter housing
Leak at the Torque Converter End
• Converter leak in the weld area
• Converter seal lip cut. Check the converter hub for damage
• Converter seal bushing moved forward and damaged
• Converter seal garter spring missing from the seal
• Porous casting of the transmission case or the oil pump
• Converter seal lip cut. Check the converter hub for damage
• Converter seal bushing moved forward and damaged
• Converter seal garter spring missing from the seal
• Porous casting of the transmission case or the oil pump
Leak at the Vent Pipe or the Fluid Fill Tube
• Overfilled system
• Water or coolant in the fluid. The fluid will appear milky
• Transmission case porous
• Incorrect fluid level indicator
• Plugged vent
• Drain-back holes plugged
• Mispositioned oil pump to case gasket, if equipped
• Water or coolant in the fluid. The fluid will appear milky
• Transmission case porous
• Incorrect fluid level indicator
• Plugged vent
• Drain-back holes plugged
• Mispositioned oil pump to case gasket, if equipped
FIGURE Leak Inspection Points(c)
(1)Wiring Harness Pass-through Connector O-Ring Seal(2)Transmission Vent Assembly(3)Converter Housing to Case Joint (Pump to Case Oil Seal)(4)Line Pressure Plug(5)Manual Shaft Seal(6)Case Rear Oil Seal Assembly(7)Torque Converter Assembly(8)Pump to Case Oil Seal(9)Pump Oil Seal Assembly(10)2-4 Servo Cover O-Ring Seal(11)Oil Cooler Pipe Connectors(12)Transmission Case(13)Transmission Oil Pan Gasket
Bill
Last edited by Bill Dearborn; Mar 1, 2009 at 02:13 PM.
