Oil Pressure Sender Square Block Leak

[2jmotorsports]

I have traced an oil leak to the sealing ring between the square block where the oil pressure sender mounts, and the engine case. This would be at sealing ring #49 in the diagram below.



Even though I seem to recall having torqued it to 35 Nm (26 ft-lbs) per Wayne's rebuild book and the Bentley, it was quite easy to turn the square block and sender assembly by hand before I took it apart to replace the sealing rings.

Does anyone have any recommendations on how to get this sealing ring to seal properly? Snug the hollow bolt (#50) a bit more or smear some Curil-T on the sealing ring surfaces?

Thanks in advance.

[cabmandone]

Assuming you used new washers.... I'd take it apart, clean the mating surfaces, assemble with 50/49/48/49 to make sure the washers are in the recessed part of the block and not askew then install the assembly. You shouldn't be able to turn by hand without a a good bit of force. Make sure you put a wrench on the block to back it up while tightening to pass through bolt (#50)

[boyt911sc]

Jose,

Do not over torque part #50. The threaded section on the crankcase where #50 goes is not as robust as you might think. There were cases that people cracked or break a piece of the threaded section that would require some machine work to fix it. Use good cooper or aluminum crush washers.

Tony

[2jmotorsports]

Thanks Tony and Nick. Ill try again with new washers and tread lightly.

[theiceman]

Originally Posted by boyt911sc

Jose,

Do not over torque part #50. The threaded section on the crankcase where #50 goes is not as robust as you might think. There were cases that people cracked or break a piece of the threaded section that would require some machine work to fix it. Use good cooper or aluminum crush washers.

Tony

yeah this is done by people who want to remove the sender from the car... ALWAYS remove 50 and the block, put the block in a vice and remove sender... trying to shortcut by trying to remove the sender from the block while is is still in the car will end is tears as Tony describes ...

i would see how 50 screws into the case without the block as a test fit and see if it is binding. if it is STOP. find a nut with a similar thread and test 50 on the nut and make sure all is good. you do not want to strip out he case by cross threading or thread damage. there is no way you should be able to turn that block by hand if it is torqued to spec with new crush washers.

[Walt Fricke]

Another reason to be careful, counterhold, etc. is that the hollow bolt is, well, hollow. So it isn't anywhere near as strong as a regular steel bolt of that size. I've cracked one by overtightening trying to stop a suspected leak.