Rear Main Seal Leak

[flatjack9]

The older white seals needed to be soaked. The instructions with these new black seals state they should not be soaked prior to installation. They also include a gauge to trim the seal to the proper height.

[Vergil]

The GraphTite seals do not need to be soaked as the old type rope seals were. When the ends of the seal are cut using the supplied spacer and knife make sure the sides of the cut seal are gently moved toward the center of the seal end instead of flared out. If flared out as the main cap is tightened it will pinch the flared portion between the cap and block which may not let the cap seat flat against the block. Above is how I do it but others have their way also. I do use a sealer under the aluminum seal holder in the block.

Vergil

[TomT/Williamsburg]

Well, tonight is the night - I've got her all buttoned up and ready to fire up. I'm going to double check everything tonight, install my headlights, and go for a test drive. Here's what I did:

1 - replaced the rear main seal using the graphite version - Aviation permatex was used on the zinc holder as per Bruce C.
2 - replaced the cam cover gasket seal, again using aviation Perm - there seemed to be no problems here but the engine had been sitting for awhile before I took it apart so I just wanted to be sure ....
3 - replaced the 1-pc front crank seal - I know some folks do not like them but I ahve had one on my 40 coupe for 9+ years with no issues. I had replaced the pan gasket so many times before this I had stretched the 1 pc seal taking the pan off so many times ....
4 - so much easier doing the pan gasket standing up rather than from underneath and on my back!
5- since I had to remove the TC cover, I replaced its gasket
6 - I also fixed a bunch of other small items that needed fixing that had either come loose, broken, or whatever from my several long road trips.

Hopefully I have good news for tomorrow - I'm driving it to Winston-Salem, NC on Sat!!

[Hamtown Al]

Go get 'em, Tom! We're pulling for ya! Al

[TomT/Williamsburg]

Originally Posted by Charlie ny

Tom,
My fresh stroker 8ba has a rear main leak, getting worse as the miles
pile up. Tell us about the graphite rope seal....where did you get it etc. That info
will be most appreciated in Sept when I yank the motor out for the 3rd time.
Hershey this year ? We're at RCB 48 - 50
Charlie ny

Charlie - I got the seal in a Best engine gasket set - MACs also has them separately as do some other suppliers. SEEMS like a no brainer - we'll know more tomorrow and after my trip ....

Hey, this latest motor and tranny pull was my 7th since the car has been on the road, and it will be 2 years this coming August!

That's hot rodding, isn't it? You've got to pay to play!

[TomT/Williamsburg]

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OK - after a short test run to get gas and a 15 minute or so idle in my driveway afterwards, I only had a small 2" diameter "wet oil" spot on my drip pan after sitting o-night. So far, so good - this weekend's run to Winston-Salem, NC will tell the tale ....

Thanks for all your support, fellas!

[TomT/Williamsburg]

Originally Posted by richard crow

that set up you have looks like the eng could come out ez buy some of that dye you put in the oil ren eng till it leaks remove eng remove pan & flywheel you schould see where the leak is could be back plate or there is a pipe plug also could be leaking

Richard - where can I find the die you are talking about? Thanks ...

[TomT/Williamsburg]

Well, unfortunately, the leak is back - not as bad as it has been, but still significant. I went through a little more than 2 qts in the 550 mile round-trip to a show this past weekend .... I'm checking on the die Richard Crow has spoke of and I'll run that in the engine before pulling it once again ....

[BillM]

Sounds almost like there might be a venting issue. Do you have the original pan with the vent at the front for exhaust and the filtered cap on the fuel pump stand at the rear for the inlet?

[hotcoupe]

FWIW, i used to use aviation permatex until i discovered "hylomar". it`s a little hard to find and expensive, but it does the job.
tom

[flatjack9]

The only time I had a leak from my rear seal was when my oil fill/vent cap got gummed up and allowed a pressure build up in my engine. Cleaned the screen and no more leak.

[Henry/Kokomo]

"Hylomar" is available from Silver Seal Products. They have a website from which you can place orders. Good stuff!

[TomT/Williamsburg]

Thanks for the help here, gents ....

BillM - yes, I do have the stock pan w/vent and vented cap at the oil fill tube above the fuel pump

Flatjack9 - I will clean that out pronto (although I'm pretty certain there's no blockage)

Henry/hotcoupe - I will pick up some hylomar .....

FWIW, I'm using an 8BA oil pump which provides more pressure than the stock pump. Now, I've used this in my french block for years without the leaks I'm having now but I thought I would throw it out there ....

[David J]

The use of hi-volume oil pumps on early motors that don't have rear seals can cause this . Do you have a rear main drain pipe in place ? If yes these will also cause a leak [ bad ] if screwed in too far . They act as a dam if in too far . This may not apply to your situation but these are definately problems at times .

Originally Posted by TomT/Williamsburg

Thanks for the help here, gents ....



FWIW, I'm using an 8BA oil pump which provides more pressure than the stock pump. Now, I've used this in my french block for years without the leaks I'm having now but I thought I would throw it out there ....

[TomT/Williamsburg]

Originally Posted by David J

The use of hi-volume oil pumps on early motors that don't have rear seals can cause this . Do you have a rear main drain pipe in place ? If yes these will also cause a leak [ bad ] if screwed in too far . They act as a dam if in too far . This may not apply to your situation but these are definately problems at times .

A "rear main drain pipe" - any pics of what this is?

[JonC]

I believe what this is, is the small 1/8 inch pipe that would screw into the rear main bearing saddle. It's purpose is to allow the oil that accumulates in the rear seal area to drain back into the pan. My 36 has one and I did not think I could screw it up so far to block the draining of oil, but I never tried to.

[TomT/Williamsburg]

Originally Posted by JonC

I believe what this is, is the small 1/8 inch pipe that would screw into the rear main bearing saddle. It's purpose is to allow the oil that accumulates in the rear seal area to drain back into the pan. My 36 has one and I did not think I could screw it up so far to block the draining of oil, but I never tried to.

OK - now I'm understanding this - the motor in my roadster is a 59 from a 40 Ford - I'm not using one of the earlier motors.

Also, the 8BA pump I'm using is the stock unit, not an aftermarket one, and it puts out more pressure than what originally came with the engine ....

[David J]

This is a 33 but the pipe thing is the same idea . You can definately screw them in to the point that the pipe lip will be above the bottom of the groove = dam . You probably aren't running one but if you are I only turn them in 5 turns & loctite them . No worry about it being a dam at 5 turns . ADDING After reading your last post a 40 definately had this pipe new [ pt # 81A 6326 ] listed as 38-42 V-8 90 & 100 horse . Did someone modify your crank for a seal ? How much oil pressure ?

Originally Posted by TomT/Williamsburg

A "rear main drain pipe" - any pics of what this is?

[TomT/Williamsburg]

Oil pressure - at speed (65 mph) 40-45 lbs, hot idle, 20 lbs at a minimum ....

I did not notice a hole in my rear main bearing for this pipe when I had her apart last week but then again, I was not looking for one .....

Again FWIW, the first engine I had in this car was a stock 85 HP 40 engine with a stock oil pump for a 40 engine. I did drive the car on 2 - 500+ mile round trip shows and I only had the normal flattie drip - I'm thinking I should perhaps change back to the stock oil pump for this engine the more we speak about this. From what I remember, oil pressure was probably down 10-15 lbs overall from the readings I gave you above ....

[flatjack9]

Tom, that pump is definetly not your problem. If the engine is a 59, it was not standard in a 40, it is a 46 - 48 model. Your engine does not have the drain pipe.