Hi Folks - Thought I’d throw out a quick question on behalf of my brother and his project. He is screwing together a ‘68 Sport Wagon that will have a 300 V-8. You read that right, he’s going retro! Anyway, he’s in the process of assembling the motor for which he bought a new FlowKooler water pump. Of course, the pump body matched up fine with all bolts threading in by hand. However, once he got it snug, he noticed the bottom of the impeller dragging against the mounting boss. Putting a grunt on all the bolts seizes the pump solid. He thought of, but has yet to try two gaskets to see if that provides enough clearance. If not, it’s a moot point. If it does, he’s wondering if there are any issues from stacking two gaskets. Leakage, of course, is the first concern, but also could you have too much clearance under the pump to cause some blow-by reducing the efficiency of the pump? We’re looking for someone with a little more Buick-specific knowledge regarding water pumps in general and these FlowKoolers specifically. His efforts to contact this company by phone and email failed. Hope someone has some ideas! Thanks!
Sounds like you have a good understanding of both extremes of the problem. I once bought a 79 Toyota Supra that had no water circulating and found the last water pump that went bad routed out the housing so the clearance between the impeller to big for it to pump. The way I figured it out was to press the impeller slightly backwards on the shaft, reinstalled the pump and water started to move. It sounds like the impeller was pressed on the shaft improperly. Any way you can compare it to the old one, or, go back to where you bought it and get another off the shelf to see if it's different?
Sounds about right. You can also use dial calipers and measure to see what is going on there but improper assembly does sound likely. Jim
If by chance you do use 2 or more gaskets, I would use some shellac between the gaskets. Personally whenever I install a paper gasket, water pumps, timing covers etc. I always put a thin film of shellac on both surfaces. I have never had a leaker by doing this. I have removed freshly installed gaskets (other people installed) that were leaking and sealed them up with a thin film of shellac. Keith
