My Dayton/Speedaire 4B236, using the seems-to-be-common 4B247 pump seems to have developed an issue with the gasket between the head and the valve plate. Efficiency is down and it heated up enough to melt the plastic air filter. According to diags, that sort of problem is an issue with the valve plate and/or the gasket(s). Sure enough, there's a split int he gasket between the intake and exhaust sides.
My issue is that all the kits I see for this pump use a rectangular o-ring between the head and the top of the valve plate. Mine uses a steel shim gasket that is as large as the valve plate itself. This wouldn't be such a problem if the valve plate assembly was still available, but it shows as NLA/indeterminate backorder almost everywhere I've looked, and I fully expect anyone that shows to be able to get it to *not* actually be able to do so.
My question then is: is it possible to get a replacement steel shim gasket. I can't even seem to find a part number for it - all the parts houses and diagrams show the o-ring style gasket.
The bores of the pump look perfect - I'd hate to have to completely replace the pump (which, ironically enough, *is* still available, at least as an aftermarket piece.)

Thanks,
Kevin

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