In message , fred
writes

I don't know what he used but there is no shifting the caps either by
hand or with the aid of two pair of pliers. (one to hold the stem, one
to twist the cap).

Rubber-stem valves?
I wouldn't want to be using a pair of pliers on them, tbh.

Any other suggestions to shift them ?

If they REALLY, REALLY can't be shifted, then take it to a local tyre
place, and ask them to fit new tubes.


WTF. Why do you think I requested assistance here

Heat? Dust caps lie about the floor of any tyre fitting shop so you
don't have to purchase replacements.

Damp cloth wrapped around valve stem and hot air gun/paint
stripper/wifes hair dryer on valve cap.

Hot plastic stretches so your pliers should finish the job.

IME Locktite products soften with heat.

--
Tim Lamb