HEY fellas, what do you think? I had an oil leak behind timing gear case, took all apart, pulled timing cover,pulled pump, cam, took tappet cover off, used the wooden dowels,and so on...... I reassemble finally get it to fire up and run, let it idle for about 5 min, go to look for leaks and the tappet cover at the back above the starter leaking like a siv, worse than the leak I took it apart to fix. i used a cummins rubber gasket put tab that says front in the front , stumped as to why this leaks , could it be off center a little , i torqued the bolts to 18 lbs ft like book said , now have to pull pump back off to fix this leak or is there another method, tnaks for any input ,

 

Its quite common for guys to get a leak on the tappet cover after a replacement. I don't take off tappet covers unless they are leaking already or I'm doing a rebuild. The tappet covers deform over time and are always harder to seal up the second time around.

Make sure that your breather is free of any obstructions. You could just be building too much crankcase pressure and pushing the gasket.

If you pull the cover wipe it all down clean. Inspect the seal to make sure it is installed correctly, then apply some sealant to the gasket or block. Then reinstall. I take the hardware to hand tight then adjust the cover a little here and there to make sure its in place properly. Then torque it down. After that let the sealant cure completely before you fire it up.

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What is install correctly, tab that say front in the front and readable from the side when looking at it, one side thicker than the other ? which side goes toward block thin side or thick side

 

I'm not sure which manufactures gasket you are running. Generally the printed side faces out and the wider flange on the gasket is against the block.

 

I believe it is a cummins gasket purchased from Mcoy Freightliner, Im pretty sure that is how I installed it , but I will find out when I take it back apart, thanks for the input.