Announcement

Collapse
No announcement yet.

Oil leaking? Think it is the rear main? read this

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Oil leaking? Think it is the rear main? read this

    Several threads have popped up here about various oil leaks.
    Well, on vintage stuff, ya gonna have'em.
    But we try to keep them small.

    If you think you have a rear main leak, Rich Fallucca has a good read on this:
    http://antiqueenginerebuilding.com/REARMAINLEAK.html

    BUT there is one more thing to check, and it might be worth it to check this first:
    (ya learn a lot from the old-timers)
    The right front motor mount bolt goes all the way thru the timing cover. Meaning it is subjected to a boatload of oil.
    Oil can easily work its way out here, and run rearward along the top edge of the pan, and work its way down the flywheel housing and end up right where it appears to be coming from the rear main.

    Be sure to remove this bolt, clean it and the timing cover threads well, and re-install using Permatex Ultra Black gasket sealer.
    We avoid the blue sealer since it will not stand up to petroleum products.
    Have fixed a lot of 'rear main' leaks this way!

  • #2
    Learn something new everyday! Read a ton on this subject and this is a new one to add to the list for sure!

    Comment


    • #3
      Thats good info:

      there are also some front pan bolts that go into open holes into the oil on the timing cover. I forget exactly which ones, does anyone know?
      3 ~ Tudor's
      Henry Ford said
      "It's all nuts and bolts"


      Mitch's Auto Service ctr

      Comment


      • #4
        Even "normal" mist from the oil cap can blow back under the starter & onto the flywheel cover & appear to be a rear main leak! This usually happens on a LONG, FAST trip. An old sock, over the filler will prevent it.
        NOTE: If you BANG the oil cap down REAL TIGHT, you WILL REALLY have a REAR MAIN LEAK!! It'll go away when you reset the cap properly.---(ASK ME HOW I KNOW?) At the COFFEE HOLE, someone asked, "WHY is Minerva PUKING"?
        Bill W.
        Last edited by BILL WILLIAMSON; 05-27-2017, 11:11 AM. Reason: I fergot sumpthing!

        Comment


        • #5
          The over tight oil filler or breather cap, really bit a couple of guys in one of the clubs I belong to. They put a borrowed engine in and within a few miles at the start of a tour, oil was pouring out the back. They took it out, and the owner of the engine walked in and noticed the cap jammed on. My neighbor is now "borrowing" that same engine, while he rebuilds his, and it doesn't leak

          Comment


          • #6
            Yeah, I kept having this leak from my fresh new built. It is my fault. The fly/block gasket while motor was waiting to install had got wet, dried and was a little wrinkled. I said what the hell and put a little gasket sealer on it....paid the price for .75 cents and had to pull engine again. New gasket and RTV should resolve the issue no oil on main bolts or fly.

            Comment


            • #7
              Originally posted by Beauford View Post
              Yeah, I kept having this leak from my fresh new built. It is my fault. The fly/block gasket while motor was waiting to install had got wet, dried and was a little wrinkled. I said what the hell and put a little gasket sealer on it....paid the price for .75 cents and had to pull engine again. New gasket and RTV should resolve the issue no oil on main bolts or fly.
              I guess you mean the rear camshaft gasket! Yes they will leak like a sieve
              i am glad you got it resolved, as i said from the get go, you shouldnt be leaking that much on a new motor.
              3 ~ Tudor's
              Henry Ford said
              "It's all nuts and bolts"


              Mitch's Auto Service ctr

              Comment


              • #8
                Yup...not James fault for sure. Just a over anxious and lack of time trying to do things too quick. I have paid the price. So when I get off work in the morning I hope to have gasket, shims, housing adjusted, flywheel on and aligned with pressure plate and clutch disc. Sleep, go back to work, get off and hoist motor in, sleep and go back to work. Hopefully everyone else will have a nice long weekend!

                Comment


                • #9
                  I still have a slight weeping of oil. James told me to snug pan bolts which I did but still get a little coming down the dust cover. The weird thing is the chassis hasn't been started in a week and the car is facing slightly down hill in my side yard while I'm painting in the garage. I am going to get UV / Dye to figure this one out. I will post pics this week.

                  Comment


                  • #10
                    Originally posted by Beauford View Post
                    I still have a slight weeping of oil. James told me to snug pan bolts which I did but still get a little coming down the dust cover. The weird thing is the chassis hasn't been started in a week and the car is facing slightly down hill in my side yard while I'm painting in the garage. I am going to get UV / Dye to figure this one out. I will post pics this week.
                    Just in case,

                    http://www.sacramentocapitolas.org/s...et-Article.pdf
                    3 ~ Tudor's
                    Henry Ford said
                    "It's all nuts and bolts"


                    Mitch's Auto Service ctr

                    Comment


                    • #11
                      Interesting....

                      Comment


                      • #12
                        Can't be a rear main if its not coming out hole nor while running but what the hell I know....I just look at that "Red" book and put stuff together. LOL

                        Comment


                        • #13
                          I sent my check in for a local club, met another A'er (I know 3 now, 240 years of combined knowledge) and have Les book. Shouldn't leak stop? I heard that at the other place all the time. HAHAHHAHA...problem should be solved!!!

                          Comment

                          Related Topics

                          Collapse

                          • MIKE DERUITER
                            REAR MAIN LEAK
                            by MIKE DERUITER
                            AFTER PUTTING ABOUT 50 MILES ON MY 29 MODEL A . THE NEXT MORNING I NOTICED A A FAIRLEY LARGE OIL SPOT UNDER THE REAR MAIN . I AM PLANNING ON DROPING THE PAN SOON , ANY THOUGHTS TO WHAT I MIGHT FIND ARE APPRECIATED
                            08-05-2018, 02:56 PM
                          • Adog
                            Newby needs a question answered on 29 model a pickup rear main oil leak
                            by Adog
                            Just bought a new to me 1929 model a pickup. Engine runs fine with no knocks. After a 20 minute test drive and parked on concrete, oil flowed out of flywheel housing. A area approximately 18 inches In diameter. Oil also leaking from left side of engine pan and base of oil fill pipe.

                            I have all of Les Andrews books. Question, is it possible to remove pan and the rear main cap for inspection...
                            01-23-2020, 07:31 AM
                          • Tom Rode
                            Significant oil leak
                            by Tom Rode
                            So I've been driving this car a week or two now, parked in garage it leaks no oil, go for a drive and come back and park it on driveway and it drips oil from the weep hole in the bell housing for 5 or 10 minutes after I return. Clearly leaking while running. Read some about clogged oil return line from the rear main bearing, and other issues regarding leak at bearing and/or seal. Have read other sources...
                            11-13-2019, 08:34 AM
                          • BillLee/Chandler, TX
                            Too much oil?
                            by BillLee/Chandler, TX
                            I have heard the story that over-filling the pan on an A engine will cause the rear main to leak. I have no reason to NOT believe this, but I would sure like to understand WHY it is so.

                            Anybody with the answer?

                            Thanks.

                            Bill
                            02-19-2019, 08:54 PM
                          • Dennis
                            Leak at the rear of the engine and not the rear main?
                            by Dennis
                            I remember in the past this being brought up and I think it was George Miller that commented one of the bolts holes near the camshaft at the back of the block goes through. Well the last time I forgot to seal that bolt when I put it back together. And yes she was a leaker. I also discovered the hole on the left side above the crankshaft journal goes through. So it's sealer for both of those bolts...
                            07-05-2018, 03:31 AM
                          • Jackc
                            Oil Leak, just asking
                            by Jackc
                            Okay, I know," if it's not leaking its out of oil." BUT, after driving I get a medium sized puddle of oil out the flywheel cover (cotter pin).
                            I have removed the cover and run it, looked at the rear main (dry), checked the pan bolts, and verified the oil return line on the block side is not leaking.
                            I am thinking the cam gasket, but wanted to see if anyone had other ideas before...
                            10-04-2019, 10:15 AM
                          • Tom Rode
                            Yikes - Manufacturing Oil
                            by Tom Rode
                            Did some riding the past few days thanks to glorious run of weather. Now I find this morning that I am "making oil"!! I was 1/2 way between the F and L mark when I headed out yesterday, topped off water in radiator (most of which flow back out under expansion), when I parked for about 20 minutes at one stop noticed more than usual amount of oil under car when I pulled out (about 2 inch across...
                            12-26-2019, 01:37 PM
                          • CSPIDY
                            Switching to a detergent oil
                            by CSPIDY
                            I am in the process of cleaning any sludge and old oil from my A’s little motor. Dropped the oil pan and I guess I am missing the rear main cap drain tube. Yikes...
                            02-07-2019, 09:23 AM
                          • CSPIDY
                            Bell Housing cover?
                            by CSPIDY
                            is there a cover that goes on the forward side of the bell housing, just behind the oil pan?
                            and
                            is it too late install with the oil pan on?

                            There are threaded holes, and the rear main cap is exposed....
                            05-05-2019, 01:31 PM
                          • CarlLaFong
                            Oil Leak
                            by CarlLaFong
                            Well, after some, in depth, diagnosis, it seems my "oil leak" is, mostly coolant. I can't tell precisely where its coming from. The car has a pressurized system and an overflow added so I'll have to get it up to temp and have a look see. It is leaking oil from the rear main, as well. I think I'll drop the pan and Plastigauge it. I have a rather steep, long driveway here at The Fongderosa...
                            01-15-2018, 02:06 PM
                          Working...
                          X