Do I panic? - Rear main oil leak.

I spoke too soon. It is still dripping, and getting progressively worse. It was not dripping after I took it for a drive last night and I did not notice much dripping over night, so I made a couple of carburetor adjustments I had been putting off, and took it for a drive to my local hardware store. Well, the car left a noticeable deposit on the pavement. I drove it home and was still dripping on the driveway after I stopped.

Argh!
 
Last edited:
FIRST NOTE: I said 20/50 Valvoline Racing Oil...You said Valvoline 50 in your post....don't use straight 50.

Drip pan at any auto store...I know Auto Zone has them, near the speedy dry and "pig" rolls. Relax....you can see how little is actually coming out by checking the oil level. You should check the trans and rear too. Everything leaks. Here's a link to Amazon, just as an example. See all the sizes! Lot's of cars must leak or they wouldn't sell these.

https://www.amazon.com/Lumax-LX-1711-Silver-Galvanized-Drip/dp/B000MD3EIA/?tag=atomicindus08-20
 
If you have an AutoZone nearby they have them as well. They 're a very good size and almost look like an oversized cookie tray, but well worth it. I put a piece of cardboard in it to absorb drops, but they definitely help keep the garage floor cleaner.
 
Install a Rear Main Janitor. https://www.snydersantiqueauto.com/...EAR-MAIN-JANITOR?fromCategory=SearchByKeyword I have one on my car to catch any oil that may drip altho my engine leaks very little since installing the "modern" seal and inserts.

I put a feminine napkin in the Rear Main Janitor to absorb any oil and change it once a month... :p :p

A reverse scroll on the front pulley cured my front seal leak.

470286


Back when the houses in my neighborhood were built the builders had the right idea of putting a grass strip in the middle of the driveway...
 

Attachments

  • Pully.jpg
    Pully.jpg
    38.6 KB · Views: 106
Last edited:
I tried some racing oil in a c---y, 20w50, at the weekend most of the oil was gone? Went back to normal 10w-30 and no more oil loss.
 
Just to be clear about this, I know that Model A's are well known for leaking and virtually every Model A leaks to a significant degree. Even our Special Coupe (Little Willie) leaked a little when it arrived here in New York in April. I inherited it from my father and it has been in the family for 64 years, since 1957.

The difference now is the much larger volume of oil coming out and the suddenness of it happening. The oil started to come out like it is now only this Friday/Saturday. This is a bit concerning to me. The suddenness clearly shows that something changed. I am not sure how drastic of a change, but a change.

I think I would feel more comfortable knowing exactly what changed so it can be dealt with properly. If there is something really wrong it needs to be fixed soon so that further damage can be avoided. If it is something minor, it can be dealt with accordingly.

The interesting thing is that Little Willie drives better now than at any time since joining us in New York.

I hope you can understand where I am coming from here.

Bill
Walworth, NY
 
Last edited:
In your case I’d drop the pan and look for the tube on the rear main. Look for metal in the dipper tray and in the pan. Check end play with a dial indicator. Have someone with a lot of experience do this if you don’t feel you are capable of the task. Does not matter what is wrong to make it leak as bad as you claim. Everything mechanical fails eventually, sometimes sooner or later.
 
philcobill said:
I hope you can understand where I am coming from here.

Bill Walworth, NY
Click to expand...

I'm hearing you Bill. Below are a couple pictures of why I went with inserts a couple of years ago. Rear Main...

470293


470294
 

Attachments

  • IMG_1171.jpeg
    IMG_1171.jpeg
    28.4 KB · Views: 102
  • IMG_1184.jpeg
    IMG_1184.jpeg
    33.1 KB · Views: 102
denniskliesen said:
In your case I’d drop the pan and look for the tube on the rear main. Look for metal in the dipper tray and in the pan. Check end play with a dial indicator. Have someone with a lot of experience do this if you don’t feel you are capable of the task. Does not matter what is wrong to make it leak as bad as you claim. Everything mechanical fails eventually, sometimes sooner or later.
Click to expand...

Now my question is, is the car okay to drive, or should I wait until I can have things checked out?

I checked the oil and it is still full. However, the dipstick felt different like there is something in the bottom of the pan that wasn't there before. Or am I imagining things?

Bill
Walworth, NY:confused:
 
Last edited:
Can you confirm there is no obstruction in the breather tube, i.e., that the breather cap sits up a bit from the tube when the cap is inserted. This breather tube MUST be open. And by all means confirm there is no obstruction in the breather tube. Some guys over the years have stuffed brillo, scratchy pads, rags etc. in the tube. BAD MOVE. If that breather tube is obstructed, it will push oil out your rear main BIG TIME. Did you happen to replace the breather vent cap recently? Worth checking...
 
Well, it looks like something is seriously wrong with the engine.
We just tested the compression on all four cylinders and they were in the 70 to 75 psi range (Tuesday 10 August 21). However, there was water in the Number 1 cylinder. Not sure now if there was water in Number 2. I suspect a blown head gasket.
I adjusted the timing over the weekend and the engine overheated. The coolant spewed out of the overflow. It ended up that the timing was slightly retarded. I imagine the cam screw was not completely tight enough. Anyway, I fixed that and put in more coolant. The engine has been running just fine from idling to cruising speeds.
We tested the cylinder compression on Saturday (7 August 21) and they were all just under 75 psi.
It has not occurred to me until just now that the oil leak, the overheated engine, the coolant in the cylinders could be all related.
The oil does not look milky, the compression is fine (see above), I am losing coolant (the radiator level is down), I did not see bubbles in the coolant, and the engine is running fine.
Any ideas what is going on?
Bill
Walworth, NY
 
Last edited:
Greg Jones said:
Can you confirm there is no obstruction in the breather tube, i.e., that the breather cap sits up a bit from the tube when the cap is inserted. This breather tube MUST be open. And by all means confirm there is no obstruction in the breather tube. Some guys over the years have stuffed brillo, scratchy pads, rags etc. in the tube. BAD MOVE. If that breather tube is obstructed, it will push oil out your rear main BIG TIME. Did you happen to replace the breather vent cap recently? Worth checking...
Click to expand...


That seems like a possibility.
 
I think you are way overthinking things. Try simple first: your oil leak may be due to overfilling the pan (you said you put 4.5 qts in at the change). Drain a quart out, check the dipstick, fill carefully only to the full mark. Drive it and see if it still leaks. Greg is right about the filler tube.
It doesn’t sound to me anything like a blown head gasket. Maybe retorqueing the head nuts would stop any possible leaks. Loosen them all and retighten according to the book.
If you are using a stock dipstick it won’t touch anything in the bottom of the pan. It isn’t long enough. Your coolant may have overflowed because it was was too full.
How do you know there’s water in the cylinders?
If the car was running well yesterday there is no reason to mess with the timing or carb setting today. Quit fussing with it! Tinkering is one thing, but arbitrary adjustments only complicate things. An oil leak will not be solved by adjusting the timing and carb.
 
I would check torque on all of them. I do 55#. Some recommend slightly loosening the nuts, then torquing in one wide swing of the torque wrench. (This topic could hijack the thread!) Anyway, can't hurt to check torque.
 
Greg Jones said:
I would check torque on all of them. I do 55#. Some recommend slightly loosening the nuts, then torquing in one wide swing of the torque wrench. (This topic could hijack the thread!) Anyway, can't hurt to check torque.
Click to expand...
The head is made of aluminum. Does that make difference with the amount of torque?
 
Dennis mentioned the rear main cap and drain tube. If you drop the pan, make sure it is there and clean. I found in one of my cars where a previous owner lightly crimped the end of the drain tube and dropped a ball bearing into it so the oil would back up and flood the rear main. Not a good idea. It would leak a lot when the oil was cold and thick and then subside when the engine got warmed up. Also, in New York I would not use 50 wt. oil. It the bearings are quiet, use 10W-30 weight oil. I have heard some folks are using a pan with pad installed to collect the oil drippings while driving. Ed
 
I am not sure about aluminum torque values, as I have never had an aluminum head. Hopefully another forum member can offer advice. Do you know what type of head you have so someone can help with a torque value?
 
You must log in or register to reply here.
Back
Top