Subframe mounts - stopping the rot

Having replaced the front subframe mounts, I want to do all i can to prevent them rotting, and considered filling the 'void' as the main issue appears to be water etc. sitting inside the mount. What have others done / is there a recognised way to do this? I'd rather not just fill them with foam or gunge, and would like to find a 'cap' that will fit.

I've considered going round the supermarket with a mount, seeing if i can find an aerosol lid that will fit snugly inside the mount, but i'd probably get arrested

Any suggestions?

Bottomguard underseal spray or similar.

Sundance

Fill them with wax?

Hi. When I bought mine nearly four years ago I noticed that the previous owner had placed a strip of aluminium foil tape over the subframe holes to prevent water and other wet crap getting into them. So far so good, it seems to be working well.

They came out of the factory with either a plastic cap or black tape over the access holes for the wishbone bolts.

I changed mine for the stainless ones, not much help unless you want to spend more money. :coat:

I also fitted the front stainless ones, so they will never rot again....back ones were not too bad so they were cleaned up and repainted and put back on the car.

Sundance

I've found some plastic caps that appear to be a neat fit inside the front mounts, once I've had a chance to fit them I'll post some photos and more details. Interesting about the rear mounts, mine were perfect despite being 14 years old, apart from one bolt shearing, which fortunately I managed to drill out without damaging the thread. They'll all get a coat of traditional underseal on any exposed threads which I can clean off if I need to dismantle them again.

So my solution is to use a 40mm push fit drainage end cap fixed into the subframe mount with Geocel mastic. The top photo shows a cap with an old mount for illustrative purposes.
This picture is before I coated the mounts with Dinitrol.