Pumping Wheel on Shabbos

Is it permissible to pump up the pneumatic wheels on a 3-wheeler children’s pram (or a wheelchair) on Shabbos? On the surface it seems this should not be makeh be’patish because the wheel is not ‘broken’ when the tire is flat.

Answer:

It appears that as you write, this will not constitute a Shabbos prohibition. In deference to those who prohibit, it is preferable to pump the wheels before Shabbos.

Sources:

The Shulchan Aruch (Orach Chaim 340) rules that it is forbidden to place feathers into a pillow for the first time, because this completes the formation of the pillow. However, if the feathers come out, it is permitted to put them back in.

The question of pumping the wheel is whether this is similar to putting in the feathers for the first time, or for the second time.

The Minchas Yitzchak (6:30) writes that each time air is pumped into the wheel, it is “new air,” and therefore parallel to installing the feathers for the first time.

However, the Minchas Shlomo (1:11:5) writes that we don’t see the process of pumping a wheel as the installment of “new air,” it is rather compared to pumping in the same air as was there before. The logic is that pumping a wheel does not resemble an action of renewal, as if a new wheel was being formed (new feathers in a pillow), but part of the regular maintenance of a wheel.

The Betzel Hachochmah (4:93) adds that air has no substance, and therefore unlike feathers of a pillow, a pumped wheel is not a “new vessel.”

The Minchas Yitzchak adds that the action is also prohibited because of the exertion involved (tirchah), and because of a concern of making a prohibited knot. However, Rav Shlomo Zalman zt”l was not concerned for these rationales.