I am getting around to restoring my windshield washers. Lots of variability in quality of parts, some hoses too short, others wrong size. The hose going to the reservoir is slight larger diameter than the squirter hoses though one vendor sells a kit with all hoses the same diameter, some too short. Another is more generous with lengths though the walls of the squirter hoses are a bit thicker making it difficult or impossible to get the hose clamps to fit.

So far I found two vendors provide the same firewall grommet which easily falls through the hole in the firewall, very little grip. The holes in the firewall for left and right squirter hoses are approximately 3/4" diameter. Grommet supplied to about 0.800" diameter, inner groove about 0.550" diameter. Takes little effort to push the grommet through the hole, little grip.

I cannot locate my originals to compare. Has anyone else seen this issue? I have no reason to believe the holes in the firewall were enlarged. I know I never opened them up.

Finally went to McMaster, bought some grommets which have an inner groove diameter of 0.750", overall diameter 1.00". Center hole diameter is around 0.304". They seem to fit quite well.

Bugs me, the grommets sold by vendors being so different. I don't see any alternative holes in the firewall which the washer hoses could route through.