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30 Closed Cab PU · 03-19-2020, 12:25 AM

Probably more info than you need, trying to be thorough.

Continue to run and re-torque cold every 50-100 miles a few times and then take compression readings again. This may be enough to cure the low readings.

Graphtite head gaskets work well, but if head is pulled again down the road are difficult to clean off the block/head.

Copper Clad gaskets work well, some prefer to spray them with copper coat.

Stay away from the modern silicone impregnated gaskets, are known to go bad. Some have good luck with them, but quite a few reports of issues.

Proper torqueing is important. Make sure you follow the recommended torque sequence. Re-torqueing after a short run hot to prevent coolant leakage into the cylinders - not uncommon for the 1st re-torque to show 35-40 lb. readings before the re-torque . Re-torque again cold, then every 50 -100 miles until torque holds. Then I prefer to re-torque in fall before storage to insure no coolant leakage (I run green antifreeze), and then again in the spring due to sitting for a period. Torqueing the 1st time is to 35, 45, then 55 lbs. in proper sequence. Threads on bolts should be clean but dry, no lube. When re-torqueing I prefer to re-torque each bolt /nut one at a time, by backing the nut off by about 1/16 - 1/8th of a turn and then re-torqueing.

For further diagnostics without removing the head you can do a leak down test. Also can check for exhaust leak into the coolant with a Napa Block Test Kit.

Also can try some Marvel Mystery Oil in the gas (4 oz. per tank) for a few tanks, may help the valve sticking/seating. Some spray a little MMO directly into the Intake manifold with the motor running. Another trick is to use a water misting bottle and spray MMO or Water into the Carb air intake with the motor running - may clean valve seating.

If replacing gasket make sure to have the head magnafluxed for cracks, and ground for flatness. Check the block for cracks, especially around the valves, and thin areas of the cylinder bores. Can check for block flatness with a straight edge for low/high spots and for being level. Use of gland rings on the exhaust manifold are recommended to help prevent teh manifold from drooping over time on cylinder 4. Many prefer the copper clad exhaust gaskets.

03-19-2020, 12:25 AM	#4
30 Closed Cab PU Senior Member Join Date: Aug 2018 Posts: 2,332	Re: Compression Test Probably more info than you need, trying to be thorough. Continue to run and re-torque cold every 50-100 miles a few times and then take compression readings again. This may be enough to cure the low readings. Graphtite head gaskets work well, but if head is pulled again down the road are difficult to clean off the block/head. Copper Clad gaskets work well, some prefer to spray them with copper coat. Stay away from the modern silicone impregnated gaskets, are known to go bad. Some have good luck with them, but quite a few reports of issues. Proper torqueing is important. Make sure you follow the recommended torque sequence. Re-torqueing after a short run hot to prevent coolant leakage into the cylinders - not uncommon for the 1st re-torque to show 35-40 lb. readings before the re-torque . Re-torque again cold, then every 50 -100 miles until torque holds. Then I prefer to re-torque in fall before storage to insure no coolant leakage (I run green antifreeze), and then again in the spring due to sitting for a period. Torqueing the 1st time is to 35, 45, then 55 lbs. in proper sequence. Threads on bolts should be clean but dry, no lube. When re-torqueing I prefer to re-torque each bolt /nut one at a time, by backing the nut off by about 1/16 - 1/8th of a turn and then re-torqueing. For further diagnostics without removing the head you can do a leak down test. Also can check for exhaust leak into the coolant with a Napa Block Test Kit. Also can try some Marvel Mystery Oil in the gas (4 oz. per tank) for a few tanks, may help the valve sticking/seating. Some spray a little MMO directly into the Intake manifold with the motor running. Another trick is to use a water misting bottle and spray MMO or Water into the Carb air intake with the motor running - may clean valve seating. If replacing gasket make sure to have the head magnafluxed for cracks, and ground for flatness. Check the block for cracks, especially around the valves, and thin areas of the cylinder bores. Can check for block flatness with a straight edge for low/high spots and for being level. Use of gland rings on the exhaust manifold are recommended to help prevent teh manifold from drooping over time on cylinder 4. Many prefer the copper clad exhaust gaskets.