TH350 Strange Dipstick Leak
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TH350 Strange Dipstick Leak
Hey All,
I recently rebuilt my TH350, everything appears to work fine except for a mystery leak out of the dipstick/fill tube. The fluid is running out of the top of the tube.
The fluid level appears to be correct (checked with motor running). I did install a new pan, but it doesn't appear to be any different than the original. The pan could be shallow, is there anyway to check to make sure that I am getting an accurate reading on the dipstick?
The breather was checked before reassembly and wasn't blocked. Any easy way to make sure this passage is still clear of debris?
I was thinking this may have been a heat issue, but sunday the car was moved a few feet and the fluid started flowing out of the top of the dipstick tube.
The strange thing is it does this randomly, I drove the car all last weekend and didn't have a single leak, but moving it a few feet and it leaks like crazy.
The first time this happened was when I moved it a short distance as well.
Any ideas???
Thanks,
-Chris
I recently rebuilt my TH350, everything appears to work fine except for a mystery leak out of the dipstick/fill tube. The fluid is running out of the top of the tube.
The fluid level appears to be correct (checked with motor running). I did install a new pan, but it doesn't appear to be any different than the original. The pan could be shallow, is there anyway to check to make sure that I am getting an accurate reading on the dipstick?
The breather was checked before reassembly and wasn't blocked. Any easy way to make sure this passage is still clear of debris?
I was thinking this may have been a heat issue, but sunday the car was moved a few feet and the fluid started flowing out of the top of the dipstick tube.
The strange thing is it does this randomly, I drove the car all last weekend and didn't have a single leak, but moving it a few feet and it leaks like crazy.
The first time this happened was when I moved it a short distance as well.
Any ideas???
Thanks,
-Chris
Melting Slicks
Joined: May 2002
Posts: 2,431
Likes: 52
From: Florida
The only thing that comes to mind is an internal pressure leak. Since the end of the tube is submerged, excessive internal pressure could push fluid out the tube rather than the vent which is not submerged. I would check the valve body bolts and if not that then lip seal/seals or oil sealing ring/rings. The random leak may be attributed to a lower fluid level exposing the bottom of tube rather than being submerged in fluid. Let us know what you find. BTW, the trans should have held around 10-11 quarts with an empty converter after rebuild, 8-9 without a empty converter.
Last edited by jimvette999; Jul 27, 2010 at 08:18 AM.
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I'm thinking I'm going to try hooking a pressure gauge up to the vent tube, that would tell me the case pressure, as well as possibly let me know if the vent is blocked right?
Or would I want to hook a pressure gauge up to the trans cooler lines?
What would "normal" pressure be?
Or would I want to hook a pressure gauge up to the trans cooler lines?
What would "normal" pressure be?
Melting Slicks
Joined: May 2002
Posts: 2,431
Likes: 52
From: Florida
I'm thinking I'm going to try hooking a pressure gauge up to the vent tube, that would tell me the case pressure, as well as possibly let me know if the vent is blocked right?
Or would I want to hook a pressure gauge up to the trans cooler lines?
What would "normal" pressure be?
Or would I want to hook a pressure gauge up to the trans cooler lines?
What would "normal" pressure be?
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Joined: Sep 2001
Posts: 63
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Thanks for the help!
I'll send TimAT a PM.
All I have for a vent is a little plastic looking thing that sticks out of the top of the transmission, guessing this should probably have a line running from it? I haven't checked the vent yet, that was one of the first things I was going to check. I was thinking of hooking a brake bleeder up to it and seeing if I was able to tell that way if it was plugged up.
I won't be able to check this stuff until the weekend, I really hope I don't have to pull the trans again
I'll send TimAT a PM.
All I have for a vent is a little plastic looking thing that sticks out of the top of the transmission, guessing this should probably have a line running from it? I haven't checked the vent yet, that was one of the first things I was going to check. I was thinking of hooking a brake bleeder up to it and seeing if I was able to tell that way if it was plugged up.
I won't be able to check this stuff until the weekend, I really hope I don't have to pull the trans again
Melting Slicks
Joined: May 2002
Posts: 2,431
Likes: 52
From: Florida
The little plastic thing should have had a cap on it that will wiggle since it snaps over the tube. No hose required/used like that on a differential.
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lol, sorry I mean I haven't checked it since this issue started. It was checked before assembly. If something got in there during rebuilding it, or after installing it I wouldn't know about it yet. I do have the little plastic thing, no cap on it though .
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Well, I was able to check the breather, and it is not clogged at all.
The fluid level is below the checkered section. When I first started the car fluid started to rush out of the dipstick tube. Once it stopped, and the motor started to warm up, I added some fluid. Shut the car off, and started it back up, no fluid was coming from the dipstick tube.
Why would fluid come out when cold, but not when warm?
Suggestions???
Thanks,
-Chris
The fluid level is below the checkered section. When I first started the car fluid started to rush out of the dipstick tube. Once it stopped, and the motor started to warm up, I added some fluid. Shut the car off, and started it back up, no fluid was coming from the dipstick tube.
Why would fluid come out when cold, but not when warm?
Suggestions???
Thanks,
-Chris
1st Gear
Joined: Jul 2017
Posts: 1
Likes: 0
Need help
Hey All,
I recently rebuilt my TH350, everything appears to work fine except for a mystery leak out of the dipstick/fill tube. The fluid is running out of the top of the tube.
The fluid level appears to be correct (checked with motor running). I did install a new pan, but it doesn't appear to be any different than the original. The pan could be shallow, is there anyway to check to make sure that I am getting an accurate reading on the dipstick?
The breather was checked before reassembly and wasn't blocked. Any easy way to make sure this passage is still clear of debris?
I was thinking this may have been a heat issue, but sunday the car was moved a few feet and the fluid started flowing out of the top of the dipstick tube.
The strange thing is it does this randomly, I drove the car all last weekend and didn't have a single leak, but moving it a few feet and it leaks like crazy.
The first time this happened was when I moved it a short distance as well.
Any ideas???
Thanks,
-Chris
I recently rebuilt my TH350, everything appears to work fine except for a mystery leak out of the dipstick/fill tube. The fluid is running out of the top of the tube.
The fluid level appears to be correct (checked with motor running). I did install a new pan, but it doesn't appear to be any different than the original. The pan could be shallow, is there anyway to check to make sure that I am getting an accurate reading on the dipstick?
The breather was checked before reassembly and wasn't blocked. Any easy way to make sure this passage is still clear of debris?
I was thinking this may have been a heat issue, but sunday the car was moved a few feet and the fluid started flowing out of the top of the dipstick tube.
The strange thing is it does this randomly, I drove the car all last weekend and didn't have a single leak, but moving it a few feet and it leaks like crazy.
The first time this happened was when I moved it a short distance as well.
Any ideas???
Thanks,
-Chris
I'm having this same problem. Did you ever get it figured out?
