394 skyrocket oil leak location

Old May 16, 2025 | 06:02 AM
  #1  
eggydrummer's Avatar
Thread Starter
Registered User
 
Joined: Jun 2022
Posts: 378
From: Eden Prairie, MN
394 skyrocket oil leak location

Can anyone tell me where you think this oil drip is coming from? The leak of oil seems to be coming from the plate pictured. Any info on what the area is, how to fix the leak, etc. would be greatly appreciated. Thanks all.


Old May 16, 2025 | 06:57 AM
  #2  
Oldsfan's Avatar
Registered User
 
Joined: Jul 2006
Posts: 331
That's either blowing back from somewhere else and collecting there, or you've got a transmission leak. I'd pull that cover and see what the front cover of the trans looks like. There's an input shaft seal and a couple of valve seals in that cover that might be leaking.
Old May 16, 2025 | 06:02 PM
  #3  
Charlie Jones's Avatar
Phantom Phixer
 
Joined: Dec 2011
Posts: 5,527
From: Apopka, FL
It's too clean and slightly red to be engine oil.
I would say it's probably a front trans seal.
It's an easy job to replace, after you have the transmission out.

While you have the trans out, check the damper.
If the springs are loose, replace it.

Last edited by Charlie Jones; May 16, 2025 at 06:07 PM.
Old May 23, 2025 | 11:45 AM
  #4  
eggydrummer's Avatar
Thread Starter
Registered User
 
Joined: Jun 2022
Posts: 378
From: Eden Prairie, MN
Originally Posted by Charlie Jones
It's too clean and slightly red to be engine oil.
I would say it's probably a front trans seal.
It's an easy job to replace, after you have the transmission out.

While you have the trans out, check the damper.
If the springs are loose, replace it.
I attached a picture of what appears to be the source of the leak, but I’m not sure. I took that little inspection cover off and it seems to be an inspection cover for the flex plate. Let me know your thoughts.

Leaking maybe from that bolt?
Leaking maybe from that bolt?
Old May 23, 2025 | 01:48 PM
  #5  
Vintage Chief's Avatar
Running On Empty
 
Joined: Jul 2018
Posts: 26,014
From: Earth
The absolute best approach to finding that leak is clean all areas best you can then add some UV Dye ($6.95) to the transmission &/or oil. Stevie Wonder could find that leak. That's what it's made for, that's why it's used.





Old May 23, 2025 | 01:54 PM
  #6  
eggydrummer's Avatar
Thread Starter
Registered User
 
Joined: Jun 2022
Posts: 378
From: Eden Prairie, MN
Originally Posted by Vintage Chief
The absolute best approach to finding that leak is clean all areas best you can then add some UV Dye ($6.95) to the transmission &/or oil. Stevie Wonder could find that leak. That's what it's made for, that's why it's used.


I agree with you Norm. I’m going to pick a bottle of this up and start there. I’ve actually started the cleaning up process, as the under carriage had LOTS of hardened gunk / oil caked all over. It’s probably been there since the late 80’s.
This is just some of the funk I chiseled and scraped off from under the car around the block, oil pan, filter, and maybe the engine cradle.
This is just some of the funk I chiseled and scraped off from under the car around the block, oil pan, filter, and maybe the engine cradle.

Old May 23, 2025 | 02:14 PM
  #7  
Vintage Chief's Avatar
Running On Empty
 
Joined: Jul 2018
Posts: 26,014
From: Earth
Two things you can use: The cheap $3/can Walmart oven cleaner or the foam engine cleaner. Both work equally as well. Lay out plenty of cardboard, don your safety glasses, grab a couple wire brushes & a long sleeved shirt.
Old May 23, 2025 | 02:17 PM
  #8  
Vintage Chief's Avatar
Running On Empty
 
Joined: Jul 2018
Posts: 26,014
From: Earth
...grab a long sleeved shirt.
One you intend to throw in the garbage when done.
Old May 23, 2025 | 02:20 PM
  #9  
Vintage Chief's Avatar
Running On Empty
 
Joined: Jul 2018
Posts: 26,014
From: Earth
Since I've done this scraping/cleaning thingy many times, another option is the Walmart home center bargain shelves. They sell some really cheap sheets for pennies on the dollar which make nice blankets to catch all the crud, roll em up, toss 'em in the garbage when done.
Old May 23, 2025 | 02:23 PM
  #10  
eggydrummer's Avatar
Thread Starter
Registered User
 
Joined: Jun 2022
Posts: 378
From: Eden Prairie, MN
Originally Posted by Vintage Chief
One you intend to throw in the garbage when done.
Thanks for the info. Gonna head to Walmart soon I think. I’ll grab a long sleeve shirt or two as well.
Not a lot is space for the Olds, but I make it work here in the garage.
Not a lot is space for the Olds, but I make it work here in the garage.

Old May 23, 2025 | 02:28 PM
  #11  
Vintage Chief's Avatar
Running On Empty
 
Joined: Jul 2018
Posts: 26,014
From: Earth
Mike - All types of room in there.
Can you get the beast up on jack stands? I see a roller dolly hanging on the wall. You have a floor jack? (Shopping list)

NOTE: Four jack stands would be far better if you can swing four. Make working on these things as comfortable and safe as possible.

Last edited by Vintage Chief; May 23, 2025 at 02:32 PM.
Old May 23, 2025 | 02:31 PM
  #12  
eggydrummer's Avatar
Thread Starter
Registered User
 
Joined: Jun 2022
Posts: 378
From: Eden Prairie, MN
Originally Posted by Vintage Chief
Mike - All types of room in there.
Can you get the beast up on jack stands? I see a roller dolly hanging on the wall. You have a floor jack? (Shopping list)
You bet I do. And this red jack stand, plus two others.

Old May 23, 2025 | 02:32 PM
  #13  
Vintage Chief's Avatar
Running On Empty
 
Joined: Jul 2018
Posts: 26,014
From: Earth
Originally Posted by eggydrummer
You bet I do. And this red jack stand, plus two others.
Sweet - good deal-e-o!
Old May 23, 2025 | 03:15 PM
  #14  
Vintage Chief's Avatar
Running On Empty
 
Joined: Jul 2018
Posts: 26,014
From: Earth
Originally Posted by eggydrummer
You bet I do. And this red jack stand, plus two others.
I just noted you stated you have a floor jack, a red jack stand plus two others. Viewing your image, please don't use a floor jack as or in place of a jack stand - very unsafe. You pop a hydraulic valve, clamp breaks, etc. that's a serious event. Get another jack stand.
Old May 23, 2025 | 03:32 PM
  #15  
eggydrummer's Avatar
Thread Starter
Registered User
 
Joined: Jun 2022
Posts: 378
From: Eden Prairie, MN
Originally Posted by Vintage Chief
I just noted you stated you have a floor jack, a red jack stand plus two others. Viewing your image, please don't use a floor jack as or in place of a jack stand - very unsafe. You pop a hydraulic valve, clamp breaks, etc. that's a serious event. Get another jack stand.
Thanks for that Norm. Picking another one up before I get under the vehicle, there will be 4 stands total, plus the jack itself.
Old May 23, 2025 | 06:15 PM
  #16  
Charlie Jones's Avatar
Phantom Phixer
 
Joined: Dec 2011
Posts: 5,527
From: Apopka, FL
Originally Posted by eggydrummer
I attached a picture of what appears to be the source of the leak, but I’m not sure. I took that little inspection cover off and it seems to be an inspection cover for the flex plate. Let me know your thoughts.

Leaking maybe from that bolt?
Leaking maybe from that bolt?
The greater possibility is that the oil is accumulating on the bolt because of a leak above it.
It's the lowest point.
Most likely the transmission input shaft seal is the culprit.
It certainly won't hurt to try some of the dye recommended, however it must be viewed with a "black light". (ultraviolet)
After cleaning it of course.
Have you driven it regularly enough to notice a loss of trans fluid?
Old May 23, 2025 | 06:34 PM
  #17  
eggydrummer's Avatar
Thread Starter
Registered User
 
Joined: Jun 2022
Posts: 378
From: Eden Prairie, MN
Originally Posted by Charlie Jones
The greater possibility is that the oil is accumulating on the bolt because of a leak above it.
It's the lowest point.
Most likely the transmission input shaft seal is the culprit.
It certainly won't hurt to try some of the dye recommended, however it must be viewed with a "black light". (ultraviolet)
After cleaning it of course.
Have you driven it regularly enough to notice a loss of trans fluid?
I’m actually going to take her out this evening, and after it gets warmed up, I’ll check the tranny fluid and let you know for sure.
Old May 24, 2025 | 08:09 AM
  #18  
Oldsfan's Avatar
Registered User
 
Joined: Jul 2006
Posts: 331
That is the plug for one of the valves in the pump. There are two of them. They both have an o-ring. That one looks like the pressure regulator. Mine leaked there. It was very tight, but I was able to replace mine through the inspection hole. I used and had ratchet and it took forever to remove and install because the opening doesn't allow much movement. A power tool would probably make it a breeze.


Old May 27, 2025 | 05:44 PM
  #19  
eggydrummer's Avatar
Thread Starter
Registered User
 
Joined: Jun 2022
Posts: 378
From: Eden Prairie, MN
So when I go to add the UV dye in the oil, can I let the engine run in park, or is it best to drive it?
Old May 27, 2025 | 05:54 PM
  #20  
Vintage Chief's Avatar
Running On Empty
 
Joined: Jul 2018
Posts: 26,014
From: Earth
Mike - That's a really good question. I don't if the transmission pump operates while in Park on your car. Most nearly all modern cars the pump operates while in Park. Others will surely be able to answer. In both cases, you should take the car for a short cruise to get as much of the UV circulating as possible is the best bet.
Old May 27, 2025 | 06:19 PM
  #21  
Vintage Chief's Avatar
Running On Empty
 
Joined: Jul 2018
Posts: 26,014
From: Earth
I suspect same process regardless of what UV manufacturer you purchased (attachment).

Attached Files
File Type: pdf
UV Dye.pdf (98.9 KB, 6 views)
Old Jun 5, 2025 | 06:16 AM
  #22  
eggydrummer's Avatar
Thread Starter
Registered User
 
Joined: Jun 2022
Posts: 378
From: Eden Prairie, MN
So, I think I located the leak using the UV dye, and it seems to originate from that inspection cover, where those plugs are. There is also a small oil leak coming from the oil pan drain plug. I changed the oil about 2 weeks ago and used a brand-new copper crush washer. I didn't want to overtighten it, so I torqued it a hair more to see if that would stop the small leak. It did not. What is recommended for that leak coming from the drain plug for the oil?

Also, at this point, I probably won't be removing the transmission to inspect that other leak, not quite sure what to do from here.

Thanks guys.
Old Jun 5, 2025 | 06:47 AM
  #23  
Vintage Chief's Avatar
Running On Empty
 
Joined: Jul 2018
Posts: 26,014
From: Earth
Originally Posted by eggydrummer
There is also a small oil leak coming from the oil pan drain plug. I changed the oil about 2 weeks ago and used a brand-new copper crush washer. I didn't want to overtighten it, so I torqued it a hair more to see if that would stop the small leak. It did not. What is recommended for that leak coming from the drain plug for the oil?
Possibility of a couple things. (1) Ensure the oil pan is flat where the crush washer is mounted. (2) Ensure it's the properly sized crush washer. (3) Install a new oil pan drain plug. Drain plug might be beveled, of the incorrect style, etc. Hard to tell exactly what the issue is, but you have options.

If those items fail to address the small leak, application/installation of an oil/gas resistant O-Ring would not be out of the question. It's certainly an area which gets plenty of attention over the years.
Old Jun 5, 2025 | 06:56 AM
  #24  
Vintage Chief's Avatar
Running On Empty
 
Joined: Jul 2018
Posts: 26,014
From: Earth
I read Charlie's previous comments regarding your oil pan drain plug here >>> 1961 Olds 98 Oil Drain Plug Size
That's stupid money for an oil pan drain plug. "...used on only Olds V8's from 61 thru 65..."
Oh boy, lucky you, eh?

https://www.ebay.com/itm/405329464716
Old Jun 5, 2025 | 07:46 AM
  #25  
Vintage Chief's Avatar
Running On Empty
 
Joined: Jul 2018
Posts: 26,014
From: Earth
Originally Posted by eggydrummer
Also, at this point, I probably won't be removing the transmission to inspect that other leak, not quite sure what to do from here.
These are handy...




Old Jun 5, 2025 | 08:45 AM
  #26  
OLDSter Ralph's Avatar
Registered User
 
Joined: Sep 2017
Posts: 5,219
From: St. Paul Minnesota
Originally Posted by eggydrummer
So, I think I located the leak using the UV dye, and it seems to originate from that inspection cover, where those plugs are. There is also a small oil leak coming from the oil pan drain plug. I changed the oil about 2 weeks ago and used a brand-new copper crush washer. I didn't want to overtighten it, so I torqued it a hair more to see if that would stop the small leak. It did not. What is recommended for that leak coming from the drain plug for the oil?

Also, at this point, I probably won't be removing the transmission to inspect that other leak, not quite sure what to do from here. Thanks guys.
Next time you change oil, check the oil pan sealing surface is smooth and no nicks or deep scratches.and anneal the copper washer according to the steps below.
1. Hang the washer from a small wire to keep from burning your fingers.
2. Heat the washer as hot as you can with a propane torch or MAP gas without melting it.
3. Drop it in a soup can of room temperature water (quench).
You can test this by bending slightly to test ductility before you heat and quench and compare it to ductility after heat and quench. Buy a spare copper washer if you want to test this procedure. Copper does "work harden". Let me know if it works.
.

Last edited by OLDSter Ralph; Jun 5, 2025 at 08:48 AM.
Old Jun 5, 2025 | 11:23 AM
  #27  
eggydrummer's Avatar
Thread Starter
Registered User
 
Joined: Jun 2022
Posts: 378
From: Eden Prairie, MN
Originally Posted by Vintage Chief
I read Charlie's previous comments regarding your oil pan drain plug here >>> 1961 Olds 98 Oil Drain Plug Size
That's stupid money for an oil pan drain plug. "...used on only Olds V8's from 61 thru 65..."
Oh boy, lucky you, eh?

https://www.ebay.com/itm/405329464716
I saw that! unreal! I am going to see if I can see any defects on the oil pan first, and check the drain plug as well.
Old Jun 5, 2025 | 11:24 AM
  #28  
eggydrummer's Avatar
Thread Starter
Registered User
 
Joined: Jun 2022
Posts: 378
From: Eden Prairie, MN
Originally Posted by OLDSter Ralph
Next time you change oil, check the oil pan sealing surface is smooth and no nicks or deep scratches.and anneal the copper washer according to the steps below.
1. Hang the washer from a small wire to keep from burning your fingers.
2. Heat the washer as hot as you can with a propane torch or MAP gas without melting it.
3. Drop it in a soup can of room temperature water (quench).
You can test this by bending slightly to test ductility before you heat and quench and compare it to ductility after heat and quench. Buy a spare copper washer if you want to test this procedure. Copper does "work harden". Let me know if it works.
.
I will definitely be changing the oil once more before BTT50's, and I will let you know if this fixes this oil leak.
Old Jun 5, 2025 | 01:55 PM
  #29  
Oldsfan's Avatar
Registered User
 
Joined: Jul 2006
Posts: 331
Originally Posted by eggydrummer
Also, at this point, I probably won't be removing the transmission to inspect that other leak, not quite sure what to do from here.

Thanks guys.
Are both plugs leaking? The lower plug can be done with the trans in the car.
Old Jun 5, 2025 | 02:24 PM
  #30  
eggydrummer's Avatar
Thread Starter
Registered User
 
Joined: Jun 2022
Posts: 378
From: Eden Prairie, MN
Originally Posted by Oldsfan
Are both plugs leaking? The lower plug can be done with the trans in the car.
as far as I can see, it’s the lower one. It’s the one that you can visibly see when you take that metal cover off. I should probably just replace that plug. I think there is a diagram in this thread with the part number that I’ll have to try and locate
Old Jun 5, 2025 | 03:45 PM
  #31  
eggydrummer's Avatar
Thread Starter
Registered User
 
Joined: Jun 2022
Posts: 378
From: Eden Prairie, MN
Originally Posted by Oldsfan
That is the plug for one of the valves in the pump. There are two of them. They both have an o-ring. That one looks like the pressure regulator. Mine leaked there. It was very tight, but I was able to replace mine through the inspection hole. I used and had ratchet and it took forever to remove and install because the opening doesn't allow much movement. A power tool would probably make it a breeze.

Any idea where I could come up with that plug? I was thinking, is it possible that the leak is the coupling limit valve? The head on that part looks more like the one in the picture I posted of the leak.
Old Jun 6, 2025 | 06:32 AM
  #32  
Oldsfan's Avatar
Registered User
 
Joined: Jul 2006
Posts: 331
I don't think your photo is of the coupling limit valve - I think it is the pressure regulator. I don't think you can see the limit valve from through the inspection cover like that. It is more on the top. You don't need to replace the plug, just the o-ring on the plug. I'll see if I can get you a part number.
Old Jun 6, 2025 | 07:04 AM
  #33  
Vintage Chief's Avatar
Running On Empty
 
Joined: Jul 2018
Posts: 26,014
From: Earth
Oldsfan - I'm out of my league here, just thought I'd puke up the part numbers as talking points so you might validate & I can save you the searching, maybe?





Old Jun 6, 2025 | 09:47 AM
  #34  
Oldsfan's Avatar
Registered User
 
Joined: Jul 2006
Posts: 331
Originally Posted by Vintage Chief
Oldsfan - I'm out of my league here, just thought I'd puke up the part numbers as talking points so you might validate & I can save you the searching, maybe?
Close. We need group 4.216.
Old Jun 6, 2025 | 10:05 AM
  #35  
Vintage Chief's Avatar
Running On Empty
 
Joined: Jul 2018
Posts: 26,014
From: Earth
Originally Posted by Oldsfan
Close. We need group 4.216.
Roger that.
Old Jun 6, 2025 | 10:14 AM
  #36  
Vintage Chief's Avatar
Running On Empty
 
Joined: Jul 2018
Posts: 26,014
From: Earth
I'm useless in this case...my parts manual jumps from page 4-56 to 4-59. Appears not to contain 4-57 through 4-58. I might find another parts manual in my library & I'll look later if you haven't found the P/N.

Pretty sure this image is useless....



Old Jun 6, 2025 | 11:40 AM
  #37  
Oldsfan's Avatar
Registered User
 
Joined: Jul 2006
Posts: 331
Part #8615856. No longer available. Having a spare transmission and working in a dealership parts department, I took the plug from my spare and matched it up with one from my bulk o-ring stock.



Old Jun 9, 2025 | 06:37 PM
  #38  
eggydrummer's Avatar
Thread Starter
Registered User
 
Joined: Jun 2022
Posts: 378
From: Eden Prairie, MN
Originally Posted by Oldsfan
Part #8615856. No longer available. Having a spare transmission and working in a dealership parts department, I took the plug from my spare and matched it up with one from my bulk o-ring stock.


Wondering if I am able to get the plug out, if I can just try and match the o-ring / seal with another one as close to it as possible?
Old Jun 11, 2025 | 12:01 PM
  #39  
eggydrummer's Avatar
Thread Starter
Registered User
 
Joined: Jun 2022
Posts: 378
From: Eden Prairie, MN
This must be it...and I went ahead and bought it. $15 free shipping on the way today.

GM Transmission Pressure Regulator Valve Seal Part # 8615856 - NOS | eBay

Last edited by eggydrummer; Jun 11, 2025 at 12:32 PM. Reason: Adding more info
Old Jun 12, 2025 | 08:13 AM
  #40  
Oldsfan's Avatar
Registered User
 
Joined: Jul 2006
Posts: 331
There ya go. NOS rubber parts kinda scare me. I had an issue with control arm bushings once. Hope it all works out for you.

Thread Tools
Search this Thread

All times are GMT -7. The time now is 09:52 PM.