I screwed up - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**71CHEVYSHORTBED402** · 08-15-2017, 01:54 PM

71-C10 402/400TH project

Alright, ha!, I was going to have the transmission rebuilt anyway, but since my error, it might actually need it.

Few weeks ago I pushed what's left of the chassis (engine/trans) into the HOT sun to wash the chassis. It was there three days. Anyway, the transmission leaked beforehand, but in the hot sun it leaked like a sieve. I still didn't see the problem turns out, but I found a tarp or cold water stabilized the leaks. Discovered the hot sun is rough on gaskets, as there was a fair oil leak as well, I believe from the valve cover.

I put the chassis back into the garage and started pulling stuff off the transmission when I came across the cap I slipped onto the transmission vent tube to prevent water damage. Yikes! I thought nothing of capping off the vent tube.

At any rate, seems I found a guy to rebuild this. 40 years experience George, with G & J Transmission Specialists. $1,100 for a rebuild (seals, shift kit, springs, kick down, torque converter).

On a side, I'm replacing the motor gaskets, but could anything have gone wrong with the block under that heat? I had the valve cover holes plugged up, for whatever it matters. As you can tell, I'm not so familiar with the guts of an engine. I have no intention for rebuilding the block.....At least I hope so, YIKES!

**Grumpy old man** · 08-15-2017, 03:01 PM

The water won't hurt anything as long as you don't start it and pump it thru the engine and trans , Sitting in the sun will never get it as hot as it gets when running so no worries there , Drain the pans and replace all the gaskets while it out .

treveiger · 08-15-2017, 04:41 PM

^^^ agreed. You could take it in to get the trans looked at/resealed at the shop for safe insurance if you want though.

**71CHEVYSHORTBED402** · 08-15-2017, 04:54 PM

Quote:

Originally Posted by Grumpy old man

The water won't hurt anything as long as you don't start it and pump it thru the engine and trans , Sitting in the sun will never get it as hot as it gets when running so no worries there , Drain the pans and replace all the gaskets while it out .

Thanks Grumps & Treveiger. Pan has since been drained. All new stuff anyhow, or mostly. It's a money pit and plenty of hours.

**Ol Blue K20** · 08-15-2017, 05:13 PM

Hmmm...I'm trying to figure out where you screwed up.

**71CHEVYSHORTBED402** · 08-15-2017, 05:57 PM

Quote:

Originally Posted by Ol Blue K20

Hmmm...I'm trying to figure out where you screwed up.

I figured the transmission vent tube being capped off plus the hot sun may have overheated, or rather "over pressurized" the transmission. Maybe even the engine (Yikes). I read where a plugged up vent tube can lead to bad seals inside the transmission.

The fluid was draining quite heavily (pressure) before I realized direct sunlight was a bummer. Even then I didn't think about the vent tube that was capped.

But if no potential harm that's good to know. I'll ask the guy to check the transmission. Any sign for improvement I'll just have her rebuilt. It's only money

midniteblues · 08-15-2017, 07:16 PM

I dont think anything got hurt either.
There is no way the sun made it any hotter than if it was running.

The vent tube being plugged wouldnt hurt it unless you have put a bunch of miles on it while it was plugged up. Then you could push fluid out of the seals,gaskets or dip stick grommet but that only when the pump is running pressureizing the trans.

Seals and gaskets are more prone too leak more during the cold when they tend too shrink or crack.

Like described in the other thread your converter probally drained and over filled the trans case which is why it leaked alot of fluid.

That doesnt mean your trans or verter is bad it just happens sometimes when they sit for a long while.

I had it happen on a th400 in a stored car twice in one year, each time i just topped it off after warm ups and went on too put many trouble free miles on that trans and it never leaked down again once it was put back in service.

**special-K** · 08-15-2017, 07:28 PM

All that you heard about plugging the vent tube is when it's running. It probably did leak like that in the sun due to no vent. The gaskets dry out when sitting and now they leak.

**Ol Blue K20** · 08-15-2017, 07:53 PM

Quote:

Originally Posted by special-K

All that you heard about plugging the vent tube is when it's running. It probably did leak like that in the sun due to no vent. The gaskets dry out when sitting and now they leak.

I agree with Tim, no screw up here.

treveiger · 08-16-2017, 03:51 PM

Quote:

Originally Posted by 71CHEVYSHORTBED402

Thanks Grumps & Treveiger. Pan has since been drained. All new stuff anyhow, or mostly. It's a money pit and plenty of hours.

Don't worry man, mines a huge money pit as well. The fix it list keeps growing but we love doing it right

08-15-2017, 01:54 PM	#1
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,118	I screwed up 71-C10 402/400TH project Alright, ha!, I was going to have the transmission rebuilt anyway, but since my error, it might actually need it. Few weeks ago I pushed what's left of the chassis (engine/trans) into the HOT sun to wash the chassis. It was there three days. Anyway, the transmission leaked beforehand, but in the hot sun it leaked like a sieve. I still didn't see the problem turns out, but I found a tarp or cold water stabilized the leaks. Discovered the hot sun is rough on gaskets, as there was a fair oil leak as well, I believe from the valve cover. I put the chassis back into the garage and started pulling stuff off the transmission when I came across the cap I slipped onto the transmission vent tube to prevent water damage. Yikes! I thought nothing of capping off the vent tube. At any rate, seems I found a guy to rebuild this. 40 years experience George, with G & J Transmission Specialists. $1,100 for a rebuild (seals, shift kit, springs, kick down, torque converter). On a side, I'm replacing the motor gaskets, but could anything have gone wrong with the block under that heat? I had the valve cover holes plugged up, for whatever it matters. As you can tell, I'm not so familiar with the guts of an engine. I have no intention for rebuilding the block.....At least I hope so, YIKES! __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assm. guide "kit" for restoring it from ground up. With assys, the guide accts for 1000s of OEM identifications and part numbers, all written in short order. 700+ images include assm, illust., charts, and points of interest. Much of the info. applies to all 67-72 GM trucks, and to a lessor degree all 67-72 GM vehicles. My build thread, and more on the guide https://67-72chevytrucks.com/vboard/...d.php?t=730025 Last edited by 71CHEVYSHORTBED402; 08-15-2017 at 06:00 PM.

08-15-2017, 03:01 PM	#2
Grumpy old man Senior Member Join Date: Dec 2013 Location: Gods country East,Tn Posts: 8,545	Re: I screwed up The water won't hurt anything as long as you don't start it and pump it thru the engine and trans , Sitting in the sun will never get it as hot as it gets when running so no worries there , Drain the pans and replace all the gaskets while it out .

08-15-2017, 04:41 PM	#3
treveiger Senior Member Join Date: Jul 2010 Location: South Dakota Posts: 4,090	Re: I screwed up ^^^ agreed. You could take it in to get the trans looked at/resealed at the shop for safe insurance if you want though. __________________ 1969 Chevy c20(Miss Hackjob)

08-15-2017, 05:13 PM	#5
Ol Blue K20 Proprietor of Dale's Corner Join Date: Nov 2012 Location: Vacaville , CA Posts: 15,834	Re: I screwed up Hmmm...I'm trying to figure out where you screwed up. __________________ "Some Days Chickens And Some Days Feathers" Dale XNGH ECV Sam Brannan 1004 R.I.P. 67ChevyRedneck R.I.P. Grumpy Old Man

08-15-2017, 07:16 PM	#7
midniteblues Registered User Join Date: Jul 2011 Location: strausstown pa Posts: 3,394	Re: I screwed up I dont think anything got hurt either. There is no way the sun made it any hotter than if it was running. The vent tube being plugged wouldnt hurt it unless you have put a bunch of miles on it while it was plugged up. Then you could push fluid out of the seals,gaskets or dip stick grommet but that only when the pump is running pressureizing the trans. Seals and gaskets are more prone too leak more during the cold when they tend too shrink or crack. Like described in the other thread your converter probally drained and over filled the trans case which is why it leaked alot of fluid. That doesnt mean your trans or verter is bad it just happens sometimes when they sit for a long while. I had it happen on a th400 in a stored car twice in one year, each time i just topped it off after warm ups and went on too put many trouble free miles on that trans and it never leaked down again once it was put back in service. __________________ 81 camaro 355 4/spd 342 posi my first love. 67 swb step 454/4spd ott 373 posi 4/7 drop. 2000 s10 zr2 little blue truck that never gets stuck. '74 heald super bronc vt8. tecumseh powered moon rover.

08-15-2017, 07:28 PM	#8
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,862	Re: I screwed up All that you heard about plugging the vent tube is when it's running. It probably did leak like that in the sun due to no vent. The gaskets dry out when sitting and now they leak. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~



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