Re: Mike P 1955 400 Slow Resto Thread!

Posted by HH56 On 2022/6/17 14:09:58

An all too common issue with the heat riser valves is the casting holding the valve flapper is broken.

If the ridges on the end of the heat riser valve casting that keep it located to the manifold or exhaust pipe is broken off or a large enough portion is missing leaving a gap, the gaskets may not do much good in resolving the leak. There are not any bolt holes in the unit to keep it firmly fixed in position without the ridges so the valve assy will be free to wiggle around with vibration and movement from the exhaust pipe. The small movement destroys the gaskets fairly quickly.

Tightening the bolts extra tight is not an option since excess torque can break the manifold casting. As far as I know, there have not been any successful repairs figured out so if you do find it broken best to start looking for a new or better one.