packick Posted January 31, 2013 Share Posted January 31, 2013 (edited) Today we fired up the newly rebuilt 322 engine in my 1955 Century. She started right up and sounds great! However we have two water leaks. One is the water pump gasket which is easy to fix. The other is coming from the driver's side front motor mount. There are 3 bolts that mount the bracket to the engine and it is the upper bolt that is leaking antifreeze. I didn't see anything in the shop manual about sealing the bolts before putting the bracket on. Could there be another reason why it is leaking? The passenger side is fine.So, does anyone have any ideas as to why there is antifreeze leaking around this motor mount bolt? If so, what is the fix? If sealer around the bolt threads is needed, what kind of sealer works best?Thanks for the advice. Edited January 31, 2013 by packick (see edit history) Link to comment Share on other sites More sharing options...
Paul Falabella Posted January 31, 2013 Share Posted January 31, 2013 Looking at the exploded views in the chassis book,seems the only things to cause a leak in that spot would be a freeze plug. Maybe the head gasket, but I think you'd see that. Take a paper towel and and start from the head. wipe down till you see some antifreeze to get a better idea where it's coming from. Link to comment Share on other sites More sharing options...
packick Posted January 31, 2013 Author Share Posted January 31, 2013 Yep, the head gasket and freeze plugs are bone dry. A friend of mine said that on some Chrysler engines one or more of the motor mount bolts go directly into the water jacket. I don't know if Buick did the same. I don't think so. Link to comment Share on other sites More sharing options...
Paul Falabella Posted January 31, 2013 Share Posted January 31, 2013 Shop manual says nothing about bolts in water galleries. Is fan blowing water from water pump leak? Any heater hoses in the area? Link to comment Share on other sites More sharing options...
packick Posted January 31, 2013 Author Share Posted January 31, 2013 The fan blowing water back is a possibility but we don't think that is the cause. After the engine was turned off for a while we could still see water dripping out from that bolt head . . . even after drying it with a paper towel. Link to comment Share on other sites More sharing options...
42crazy Posted January 31, 2013 Share Posted January 31, 2013 A remote possibility, did someone put an extra long bolt into the mount and puncture the water jacket, sounds feasable to me. Take the bolt out and see if water is "running" out, and if it is, bingo, you've found the problem. Paul Link to comment Share on other sites More sharing options...
old-tank Posted January 31, 2013 Share Posted January 31, 2013 The motor mount bolts do go into a water cavity and must be sealed on an early nailhead. In fact every bolt that goes on the engine block or cylinder head should be sealed even if you are 'sure' if does not go into a water or oil cavity.Willie Link to comment Share on other sites More sharing options...
packick Posted January 31, 2013 Author Share Posted January 31, 2013 Paul: We thought of that too. But the bolts we put in were the same ones we took out and they were all of equal length, about an inch and a half long. So we don't think that is the problem. We also thought about could the block have corroded at that point (what are the odds), or when it was hot-tanked did the metal break down at that point. But the bolts we took out were nice and clean, no corrosion. The block was also magnafluxed. Link to comment Share on other sites More sharing options...
packick Posted January 31, 2013 Author Share Posted January 31, 2013 (edited) Thanks Willie. That's what I was afraid of. What type of sealer have you found to be the best for this type of situation? Edited January 31, 2013 by packick (see edit history) Link to comment Share on other sites More sharing options...
old-tank Posted February 1, 2013 Share Posted February 1, 2013 Thanks Willie. That's what I was afraid of. What type of sealer have you found to be the best for this type of situation?Joe, On a new dry engine I would use gasket sealer ( usually permatex aviation --- the nasty brown stuff ). On this one I would use teflon tape.Willie Link to comment Share on other sites More sharing options...
buick5563 Posted February 1, 2013 Share Posted February 1, 2013 The yellow stuff meant for gas has a higher temp rating, the last time I checked. Link to comment Share on other sites More sharing options...
packick Posted February 1, 2013 Author Share Posted February 1, 2013 OK. Thanks everyone for the advice. Now I know what to do Link to comment Share on other sites More sharing options...
60FlatTop Posted February 3, 2013 Share Posted February 3, 2013 While your are up in there working it would be a good idea to pressurize the cooling system to 15 PSIG and see where the source is.Bernie Link to comment Share on other sites More sharing options...
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