C4 trans leaking
Thread Starter
Advanced
Joined: Nov 2012
Posts: 53
Likes: 1
From: Oshkosh Wisconsin
C4 trans leaking
Hi everyone,
I have a 1986 convertible that runs great, but leaks tranny fluid. I changed the fluid, replaced the seal on shift cable and it still leaks from right side of tranny. Being a convertible I have to take off the frame cross braces and drop exhaust at the headers after getting it up in the air. Done this twice and with Spring maybe coming to Wisconsin I want to stop the leak so I can get rid of drip pan underneath.
Wondering if the breather/vent could be plugged? Where is its location?
Thanks,
NOsburn
I have a 1986 convertible that runs great, but leaks tranny fluid. I changed the fluid, replaced the seal on shift cable and it still leaks from right side of tranny. Being a convertible I have to take off the frame cross braces and drop exhaust at the headers after getting it up in the air. Done this twice and with Spring maybe coming to Wisconsin I want to stop the leak so I can get rid of drip pan underneath.
Wondering if the breather/vent could be plugged? Where is its location?
Thanks,
NOsburn
Melting Slicks
Joined: Feb 2003
Posts: 2,677
Likes: 812
From: Saskatoon Sask.
Hi everyone,
I have a 1986 convertible that runs great, but leaks tranny fluid. I changed the fluid, replaced the seal on shift cable and it still leaks from right side of tranny. Being a convertible I have to take off the frame cross braces and drop exhaust at the headers after getting it up in the air. Done this twice and with Spring maybe coming to Wisconsin I want to stop the leak so I can get rid of drip pan underneath.
Wondering if the breather/vent could be plugged? Where is its location?
Thanks,
NOsburn
I have a 1986 convertible that runs great, but leaks tranny fluid. I changed the fluid, replaced the seal on shift cable and it still leaks from right side of tranny. Being a convertible I have to take off the frame cross braces and drop exhaust at the headers after getting it up in the air. Done this twice and with Spring maybe coming to Wisconsin I want to stop the leak so I can get rid of drip pan underneath.
Wondering if the breather/vent could be plugged? Where is its location?
Thanks,
NOsburn
Team Owner
Joined: Sep 2003
Posts: 25,393
Likes: 2,741
Arbee certainly covered the 'look see' - vent is mid-case top. If you have the FSM I believe that 700-R4-8 covers 'POSSIBLE LEAK POINTS'
Do you have the FSM?
Do you have the FSM?
Last edited by WVZR-1; Apr 19, 2018 at 11:54 AM.
Melting Slicks
Joined: Oct 2016
Posts: 2,024
Likes: 363
From: Central Alabama
You mentioned using a drip pan. That would make me think it leaks even when the car is not running.
If so, than it is not likely a plugged vent is causing the problem. A plugged vent tube will only push fluid by pressurizing the trans when it's running.
I would suggest cleaning the trans with brake cleaner then it should be easy to trace back the origin of the leak.
If so, than it is not likely a plugged vent is causing the problem. A plugged vent tube will only push fluid by pressurizing the trans when it's running.
I would suggest cleaning the trans with brake cleaner then it should be easy to trace back the origin of the leak.
Race Director
Joined: Oct 2008
Posts: 17,982
Likes: 1,074
From: Lansing MI
You mentioned using a drip pan. That would make me think it leaks even when the car is not running.
If so, than it is not likely a plugged vent is causing the problem. A plugged vent tube will only push fluid by pressurizing the trans when it's running.
I would suggest cleaning the trans with brake cleaner then it should be easy to trace back the origin of the leak.
If so, than it is not likely a plugged vent is causing the problem. A plugged vent tube will only push fluid by pressurizing the trans when it's running.
I would suggest cleaning the trans with brake cleaner then it should be easy to trace back the origin of the leak.
Typically this means the trans is slipping, or beginning to slip.
Melting Slicks
Joined: Oct 2016
Posts: 2,024
Likes: 363
From: Central Alabama
i was addressing the comment in the original post about the vent being clogged
it seems to imply he thinks expanding hot air and a clogged vent tube is pressurizing the system to the extent that it is pushing fluid past the seals
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Race Director
Joined: Oct 2008
Posts: 17,982
Likes: 1,074
From: Lansing MI
i realize the intent of the vent tube
i was addressing the comment in the original post about the vent being clogged
it seems to imply he thinks expanding hot air and a clogged vent tube is pressurizing the system to the extent that it is pushing fluid past the seals
Safety Car
Joined: Aug 2009
Posts: 3,751
Likes: 276
From: Melbourne, Victoria, Australia
The right side has the dipstick tube, there is a grommet that seals it, its an obvious thing to see the black rubber bit.
Make sure its flat up against the transmission, a flashlight will illuminate the area and can see it from engine bay.
The vent on top of transmission will only vent fluid if the transmission has been overfilled.
The third option is the TV cable from throttle body that is bolted to the top of the side of trans body (and don't forget there is a seal there also, if the plastic end is cracked or loose it will leak a bit of fluid most noticeable when stopped after a drive.
Don't forget if a novice has replaced the transmission and not unbolted the TV cable from trans and unhooked the cable, the cable sheath can pull from the plastic end piece causing leaks.
The fourth cause can be the transmission cooler line connection loose, that would leak to right front near the dipstick.
Pressure clean the trans area and drive home, jack the car up remove front exhaust pipes from cat to exhaust manifolds.
Get under the car with a flashlight and mirror, look around the side and around to the top to see where the fluid is coming from.
Note I had a leak at the TV cable plastic bit that bolts to the trans, was new and fitted by the transmission replace that reco'd the trans.
It was cracked ... took many attempts to find that one.....
Make sure its flat up against the transmission, a flashlight will illuminate the area and can see it from engine bay.
The vent on top of transmission will only vent fluid if the transmission has been overfilled.
The third option is the TV cable from throttle body that is bolted to the top of the side of trans body (and don't forget there is a seal there also, if the plastic end is cracked or loose it will leak a bit of fluid most noticeable when stopped after a drive.
Don't forget if a novice has replaced the transmission and not unbolted the TV cable from trans and unhooked the cable, the cable sheath can pull from the plastic end piece causing leaks.
The fourth cause can be the transmission cooler line connection loose, that would leak to right front near the dipstick.
Pressure clean the trans area and drive home, jack the car up remove front exhaust pipes from cat to exhaust manifolds.
Get under the car with a flashlight and mirror, look around the side and around to the top to see where the fluid is coming from.
Note I had a leak at the TV cable plastic bit that bolts to the trans, was new and fitted by the transmission replace that reco'd the trans.
It was cracked ... took many attempts to find that one.....
Thread Starter
Advanced
Joined: Nov 2012
Posts: 53
Likes: 1
From: Oshkosh Wisconsin
Tranny Leaks
Hi Everyone,
Thanks for the comments. I replaced the TV cable and seal and had the pan off at the same time to change fluid and insure proper fit of TV tube.
My question on where the vent tube location was thinking it might be plugged building pressure and pushing fluid out somewhere on the right side.
I live in Wisconsin and will be getting my Vette out this weekend for the first time.
NOsburn
Thanks for the comments. I replaced the TV cable and seal and had the pan off at the same time to change fluid and insure proper fit of TV tube.
My question on where the vent tube location was thinking it might be plugged building pressure and pushing fluid out somewhere on the right side.
I live in Wisconsin and will be getting my Vette out this weekend for the first time.
NOsburn
Team Owner
Joined: Sep 2003
Posts: 25,393
Likes: 2,741
Hi Everyone,
Thanks for the comments. I replaced the TV cable and seal and had the pan off at the same time to change fluid and insure proper fit of TV tube.
My question on where the vent tube location was thinking it might be plugged building pressure and pushing fluid out somewhere on the right side.
I live in Wisconsin and will be getting my Vette out this weekend for the first time.
NOsburn
Thanks for the comments. I replaced the TV cable and seal and had the pan off at the same time to change fluid and insure proper fit of TV tube.
My question on where the vent tube location was thinking it might be plugged building pressure and pushing fluid out somewhere on the right side.
I live in Wisconsin and will be getting my Vette out this weekend for the first time.
NOsburn
Race Director
Joined: Oct 2008
Posts: 17,982
Likes: 1,074
From: Lansing MI
Hi Everyone,
Thanks for the comments. I replaced the TV cable and seal and had the pan off at the same time to change fluid and insure proper fit of TV tube.
My question on where the vent tube location was thinking it might be plugged building pressure and pushing fluid out somewhere on the right side.
I live in Wisconsin and will be getting my Vette out this weekend for the first time.
NOsburn
Thanks for the comments. I replaced the TV cable and seal and had the pan off at the same time to change fluid and insure proper fit of TV tube.
My question on where the vent tube location was thinking it might be plugged building pressure and pushing fluid out somewhere on the right side.
I live in Wisconsin and will be getting my Vette out this weekend for the first time.
NOsburn
Instructor
Joined: Oct 2018
Posts: 225
Likes: 81
From: Vancouver, WA