Leaky intake manifold - pitting


Ralph50
06-14-2015, 11:34 PM
Replaced the lower intake manifold gasket. Found pitting on the aluminum intake side, some pitting on the head but pitting and corrosion on the intake. I figured it this way. The pitting will cause a leak more than a slight non flat surface so I used my orbital sander and sanded out most of the pits. The rubber seal should be high enough to compensate the slight material i sanded off. Make no mistake this was a big job. About 16 hours over 3 days.
Be careful no to loose the screws for the dist cap. I hunted and found they are non std #8-24. Since the dist housing is plastic I used a #8 ss metal screw. Make sure the orings are in the fuel lines at the back of the engine. I always use silicone grease on all electrical connections- on the rubber seal to keep them sealed. The fan blade & the big nut, approx 1.5inch, unscrew this with serpentine belt still on and use rubber hammer CCW direction. I suggest replacing the water pump as it is right in front and that might have been part of my leak. Gets lots of carb cleaner. Put a thin piece of plywood behind the radiator or you will surely damage the radiator. I replaced the lower rad hose because its too difficult to get at later. Used the upper rad hose but because it was swelled at the metal pipe I cut about 1.5 inches off and it still fit ok. I got 3 paint markers and used a multiple of different dots and colors to mark each electrical connection and any brackets. Those color dots really help as there are so many parts to be reinstalled. I will run rad flush and change the oil. Oh the best advise, remove the hood, its only 2 bolts and some hose connections, well worth getting that out of the way. Also, I will put on a 7lb pressure rad cap.

Ralph50
06-15-2015, 09:13 PM
Started the car today. Fired up quick, rev was high when started but came down quickly. I ran Preston flush, what a joke didn't clean any oil from the upper radiator. I cant figure out how much coolant goes in the system. Chilton manual says 12 quarts but is that with the overflow resovour? I empty and also used powerfull tank vac to blow out system with lower rad hose off. Looks I like can only refill with 6 quarts. Then I jacked up the back of the car and still no water came out. I guess I will add straight antifreeze and then add mixed to top off.
July 9 update, no leaks, I think the reason is the sanding off most of the pitting.
Final entry Sept 6, no leaks.

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