The Ford Barn

Colonel · 03-20-2012, 08:24 PM

The rear main leaks pretty bad from the weep hole in the bottom of the fly wheel case. It has become untolerable to drive far. Is there any way to fix this short of pulling the engine and spending a lot of $$ ? Otherwise engine runs fine. Thoughts?

Colorado Greg · 03-20-2012, 08:36 PM

Leaks can come from various places and leak out the hole in the bell housing. Check to see exactly where the leak is coming from.

http://antiqueenginerebuilding.com/REARMAINLEAK.html

Mine had a bad leak and I was embarrassed to park anywhere someone would see how bad it was

. Mine ended up being a problem with the previous install of the rear main as well as too much clearance in the bearing. I adjusted all the mains and rods, installed the real metal seal correctly and no more leaks

ctlikon0712 · 03-20-2012, 10:43 PM

Also make sure that crankcase pressure isn't forcing the oil out the rear main drain back tube. You do this by making sure your oil fill tube's cap isn't pushed on to tight and can allow the case to breath properly. The pressure pushes the oil from the pan, up the tube, and out the rear main seal if not vented properly.

Sparky · 03-21-2012, 07:12 AM

My leak was caused by a blockage in the oil drain pasage in the main bearing block.

V4F · 03-21-2012, 08:37 AM

my leak was caused by my K&N filter . not enuff breathing . installed pcv valve .......

newshirt · 03-21-2012, 09:20 AM

Sponsored Links (Register now to hide all advertisements)

My leak was caused by the oil return tube falling off.

TinCup · 03-21-2012, 09:35 AM

The article referenced by Greg is an excellent place to start. Until then several online vendors sell what we call a diaper to help control the leaking until you can sort it out. Spend some time and search through some of the older postings on rear main oil leaks and you will find a wealth of information.

Rear Main Diaper

Gary Gregory · 03-21-2012, 07:19 PM

My leak was the missing gasket between the flywheel housing and block..at the end of the cam.

Bill Steiner · 03-21-2012, 08:32 PM

Over filling the oil pan can cause a leak. use 4 1/2 gt. Bill

KGBnut · 03-21-2012, 08:44 PM

The drain tube for my Rear Main was seated too deep and bottomed out, obscuring the opening. It really was an easy fix.

03-20-2012, 08:24 PM	#1
Colonel Senior Member Join Date: Nov 2010 Location: Indiana Posts: 251	Rear Main Oil Leak The rear main leaks pretty bad from the weep hole in the bottom of the fly wheel case. It has become untolerable to drive far. Is there any way to fix this short of pulling the engine and spending a lot of $$ ? Otherwise engine runs fine. Thoughts?

03-20-2012, 08:36 PM	#2
Colorado Greg Senior Member Join Date: May 2010 Location: Littleton, Colorado Posts: 241	Re: Rear Main Oil Leak Leaks can come from various places and leak out the hole in the bell housing. Check to see exactly where the leak is coming from. http://antiqueenginerebuilding.com/REARMAINLEAK.html Mine had a bad leak and I was embarrassed to park anywhere someone would see how bad it was. Mine ended up being a problem with the previous install of the rear main as well as too much clearance in the bearing. I adjusted all the mains and rods, installed the real metal seal correctly and no more leaks __________________ "Betsy doesn't leak oil - she just marks her spot"

03-20-2012, 10:43 PM	#3
ctlikon0712 Senior Member Join Date: Feb 2011 Location: Cocoa, Florida Posts: 1,609	Re: Rear Main Oil Leak Also make sure that crankcase pressure isn't forcing the oil out the rear main drain back tube. You do this by making sure your oil fill tube's cap isn't pushed on to tight and can allow the case to breath properly. The pressure pushes the oil from the pan, up the tube, and out the rear main seal if not vented properly. __________________ Wanted: Simmons Super Power Head Craig Likon 1931 150B

03-21-2012, 07:12 AM	#4
Sparky Senior Member Join Date: May 2010 Location: Rhode Island Posts: 649	Re: Rear Main Oil Leak My leak was caused by a blockage in the oil drain pasage in the main bearing block.

03-21-2012, 08:37 AM	#5
V4F Senior Member Join Date: May 2010 Location: ca. Posts: 2,522	Re: Rear Main Oil Leak my leak was caused by my K&N filter . not enuff breathing . installed pcv valve ....... __________________ V4f

03-21-2012, 09:20 AM	#6
newshirt Senior Member Join Date: Jan 2011 Location: Colorado Springs Posts: 868	Re: Rear Main Oil Leak Sponsored Links (Register now to hide all advertisements) My leak was caused by the oil return tube falling off. __________________ Ray White

03-21-2012, 09:35 AM	#7
TinCup Senior Member Join Date: May 2010 Location: OKC / Tonkawa, Ok. Posts: 1,977	Re: Rear Main Oil Leak The article referenced by Greg is an excellent place to start. Until then several online vendors sell what we call a diaper to help control the leaking until you can sort it out. Spend some time and search through some of the older postings on rear main oil leaks and you will find a wealth of information. Rear Main Diaper __________________ Oklahoma City Model A Restorers Group.

03-21-2012, 07:19 PM	#8
Gary Gregory Senior Member Join Date: Jun 2010 Location: Maryville,Tn Posts: 302	Re: Rear Main Oil Leak My leak was the missing gasket between the flywheel housing and block..at the end of the cam.

03-21-2012, 08:32 PM	#9
Bill Steiner Senior Member Join Date: May 2010 Location: Texas Posts: 263	Re: Rear Main Oil Leak Over filling the oil pan can cause a leak. use 4 1/2 gt. Bill

03-21-2012, 08:44 PM	#10
KGBnut Senior Member Join Date: Jul 2011 Location: Southwestern Connecticut Posts: 931	Re: Rear Main Oil Leak The drain tube for my Rear Main was seated too deep and bottomed out, obscuring the opening. It really was an easy fix. __________________ Style beats speed any day, and with a lot fewer tickets.