leaking tranny fluid from the dip stick tube - The 1947 - Present Chevrolet & GMC Truck Message Board Network

crm318 · 10-19-2008, 06:17 PM

i recently installed a new motor in my truck and after everything was buttoned back up, i noticed that there is a gigantic tranny fluid leak coming from the dip stick tube where it meets at the transmission. i remember that there was an o-ring where it mates up but there is no telling how old that is. what can i do to fix this leak?

**truckdude239** · 10-19-2008, 06:29 PM

which trans mission? there is a rubber grommet on the tip stick that needs to be replaced put some good sealant on it put ti back together let it sit a day you should be good to go

MotorSeven · 10-19-2008, 06:44 PM

If it's a turbo 350 or 400, go get a newer style tube & dipstick. It has a large grommet instead of the O ring & does not leak. Also, are you sure you have the right tube/stick? If not you may be over filling which will cause leaks and other more costly tranny repairs.

RD

crm318 · 10-20-2008, 03:37 AM

its the original stick and its a th350. can i find a new grommet for it?

**truckdude239** · 10-20-2008, 07:03 AM

advance auto carrys them in there help section

Rons86 · 10-20-2008, 12:43 PM

If it's not already, the dipstick needs to be bolted to the transmission/engine or it will move around and leak again after a short while.

crm318 · 10-20-2008, 03:28 PM

i dont think that there is anywhere on the dip stick to bolt it down. if the truck is sitting level, does it mean that there is too much fluid in it?

CG · 10-20-2008, 03:47 PM

Are you talking about a small leak or is it pouring out? I had one that was pouring, and was told there was a vent tube that was probably clogged or pinched. It wasnt a trans I was going to use anyway, so I never looked any further.

blukangoo · 10-20-2008, 05:26 PM

I put a new O-ring on mine and wrapped a little Teflon Tape around it and it hasn´t leaked since.

The tube is also bolted to the Transmission like Rons86 said.

If it isn´t tight and can move around, you will never get it sealed right.

1970heavychevy · 10-20-2008, 07:29 PM

I had that same problem. I tried using a new one with the o-ring but didn't work, so I taped it but got worried that the heat would melt the tape and end up inside. I finally found one at the junk yard that had the grommet. New grommet from O'reilly's and it does need to be bolted down. Might have to tack weld a tab if nothing to mount with.

MotorSeven · 10-20-2008, 10:54 PM

Quote:

Originally Posted by crm318

its the original stick and its a th350. can i find a new grommet for it?

If it has an O-ring, you can't put a grommet on it because the tube is too big. The newer style has a narrower tube to acomodate the grommet. I can tell you this, Advance, OReillys, & Autozone do not carry the newer style. I found one at a ma & pa auto parts store($14).... you may have to look on line for one, or maybe try a CHevy dealer. & yes it does have to be bolted to the upper tranny bolt. There is a bracket on the tube for this.

RD

crm318 · 10-21-2008, 04:37 PM

yeah, mine is bolted to the transmission. ill try the teflon tape.

Green Machine · 10-21-2008, 10:01 PM

Fixed ours like this - cleaned the tranny hole and dipstick end with some brake cleaner on a rag, got a new o-ring and put thin film or black ultra silicone in the tranny hole and a little more on the dipstick end. Bolted the dipstick up and let it sit over night. Did the same with the kickdown cable. No more leaks !!!

10-19-2008, 06:17 PM	#1
crm318 Alright Alright Alright Join Date: Mar 2004 Location: Midland, Texas Posts: 1,672	leaking tranny fluid from the dip stick tube i recently installed a new motor in my truck and after everything was buttoned back up, i noticed that there is a gigantic tranny fluid leak coming from the dip stick tube where it meets at the transmission. i remember that there was an o-ring where it mates up but there is no telling how old that is. what can i do to fix this leak? __________________ 1972 Cheyenne Chevrolet red and white 357ci, Vortec heads, GM Performance high rise intake, Comp 268H .454/.454 218/218 110 LSA Quadrajet carb, Flowtech headers, 2.25 40 series HEI, Curve kit, TH 350, 3.07 gears 275/60/15s on 15x8 rallies

10-19-2008, 06:29 PM	#2
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,238	Re: leaking tranny fluid from the dip stick tube which trans mission? there is a rubber grommet on the tip stick that needs to be replaced put some good sealant on it put ti back together let it sit a day you should be good to go __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

10-19-2008, 06:44 PM	#3
MotorSeven Restoration Desperation Join Date: Aug 2006 Location: Tennessee Posts: 373	Re: leaking tranny fluid from the dip stick tube If it's a turbo 350 or 400, go get a newer style tube & dipstick. It has a large grommet instead of the O ring & does not leak. Also, are you sure you have the right tube/stick? If not you may be over filling which will cause leaks and other more costly tranny repairs. RD

10-20-2008, 03:37 AM	#4
crm318 Alright Alright Alright Join Date: Mar 2004 Location: Midland, Texas Posts: 1,672	Re: leaking tranny fluid from the dip stick tube its the original stick and its a th350. can i find a new grommet for it? __________________ 1972 Cheyenne Chevrolet red and white 357ci, Vortec heads, GM Performance high rise intake, Comp 268H .454/.454 218/218 110 LSA Quadrajet carb, Flowtech headers, 2.25 40 series HEI, Curve kit, TH 350, 3.07 gears 275/60/15s on 15x8 rallies

10-20-2008, 07:03 AM	#5
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,238	Re: leaking tranny fluid from the dip stick tube advance auto carrys them in there help section __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

10-20-2008, 12:43 PM	#6
Rons86 Registered User Join Date: Sep 2008 Location: Holt, Missouri Posts: 94	Re: leaking tranny fluid from the dip stick tube If it's not already, the dipstick needs to be bolted to the transmission/engine or it will move around and leak again after a short while.

10-20-2008, 03:28 PM	#7
crm318 Alright Alright Alright Join Date: Mar 2004 Location: Midland, Texas Posts: 1,672	Re: leaking tranny fluid from the dip stick tube i dont think that there is anywhere on the dip stick to bolt it down. if the truck is sitting level, does it mean that there is too much fluid in it? __________________ 1972 Cheyenne Chevrolet red and white 357ci, Vortec heads, GM Performance high rise intake, Comp 268H .454/.454 218/218 110 LSA Quadrajet carb, Flowtech headers, 2.25 40 series HEI, Curve kit, TH 350, 3.07 gears 275/60/15s on 15x8 rallies

10-20-2008, 03:47 PM	#8
CG BlahBlahBlah Join Date: Feb 2002 Location: Wa. Posts: 20,131	Re: leaking tranny fluid from the dip stick tube Are you talking about a small leak or is it pouring out? I had one that was pouring, and was told there was a vent tube that was probably clogged or pinched. It wasnt a trans I was going to use anyway, so I never looked any further.

10-20-2008, 05:26 PM	#9
blukangoo Neighborhood Pickle Slinger Join Date: Jan 2007 Location: Cadolzburg, Bavaria, Germany Posts: 2,224	Re: leaking tranny fluid from the dip stick tube I put a new O-ring on mine and wrapped a little Teflon Tape around it and it hasn´t leaked since. The tube is also bolted to the Transmission like Rons86 said. If it isn´t tight and can move around, you will never get it sealed right. Attached Images __________________ -------------------------------------------------- My C10 Diary Our cars: 1966 Chevrolet Chevelle 396 - TH350 1968 Chevrolet C10/CST 327 TH400/375 1969 Corvette Stingray 350 - Muncie Manual Trans 1969 Chevrolet ElCamino 350 - TH400 1970 Cutlass Supreme Convertible - 350 Rocket - TH350 1973 Camaro LT - New Engine Done - TH350 1973 Corvette Convertible 454 - TH400

10-20-2008, 07:29 PM	#10
1970heavychevy busted knuckles Join Date: Oct 2008 Location: Kennesaw, Georgia Posts: 92	Re: leaking tranny fluid from the dip stick tube I had that same problem. I tried using a new one with the o-ring but didn't work, so I taped it but got worried that the heat would melt the tape and end up inside. I finally found one at the junk yard that had the grommet. New grommet from O'reilly's and it does need to be bolted down. Might have to tack weld a tab if nothing to mount with.

10-21-2008, 04:37 PM	#12
crm318 Alright Alright Alright Join Date: Mar 2004 Location: Midland, Texas Posts: 1,672	Re: leaking tranny fluid from the dip stick tube yeah, mine is bolted to the transmission. ill try the teflon tape. __________________ 1972 Cheyenne Chevrolet red and white 357ci, Vortec heads, GM Performance high rise intake, Comp 268H .454/.454 218/218 110 LSA Quadrajet carb, Flowtech headers, 2.25 40 series HEI, Curve kit, TH 350, 3.07 gears 275/60/15s on 15x8 rallies

10-21-2008, 10:01 PM	#13
Green Machine Senior Member Join Date: Jul 2004 Location: Estherville, Iowa Posts: 3,371	Re: leaking tranny fluid from the dip stick tube Fixed ours like this - cleaned the tranny hole and dipstick end with some brake cleaner on a rag, got a new o-ring and put thin film or black ultra silicone in the tranny hole and a little more on the dipstick end. Bolted the dipstick up and let it sit over night. Did the same with the kickdown cable. No more leaks !!! __________________ 1968 C10 307 3spd Long Fleet ------ http://67-72chevytrucks.com/vboard/s...d.php?t=201103 1970 C10 305 Super T10 Long Fleet --- http://67-72chevytrucks.com/vboard/s...d.php?t=202285 1971 C20 383 TH350 Dana Posi ----- http://67-72chevytrucks.com/vboard/s...d.php?t=206894 2001 GMC Sierra 1500 C3 6.0



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