It's not you who are going through that many pumps, it is your customers. It's one thing to rig up something for yourself if your own pump fails on a weekend and you can't get to the parts store until Monday, but I think you are leaving yourself open to lawsuits from any manufacturer if you modify one of their products in the field by using non-authorized and substandard parts to repair it. And, if one of your customers houses is damaged due to one of your improvised repairs, I don't think your business liability insurance is going to stand behind you. Our parts supplier has sales from time to time when the dealers' prices are greatly discounted. We stock up on parts that we know we use in great quantity so that we will have a good amount on hand until the next sale. The pumps are not that expensive and if you have a machine that is easily accessible, changing one is not that much trouble. If you received a discount on the price of the pumps, you could use that as a cushion to be able to offer a few dollars off to a customer who might have trouble affording the regular cost of a pump replacement. At least you probably would not have to go back for a good many years if you installed a new pump. 50 washes without leaking is no test of durability. Are you replacing so many pumps because people are keeping the washers so long? If that's the case, when you charge them for installing a new pump, you can point out to them how much money they have saved by not having to buy a new washer because their Kenmore or Whirlpool is lasting so long.
I think "jury-rigged" is the term you are looking for. It is more than a matter of PC. It is about respect for yourself and your readers. You respect yourself too much to let them know that you would use that kind of language and you respect your readers too much to force them to decide whether to let such usage slide and appear to be bigots themselves or let you know, as I do, that it makes me angry. Not one of us has or had any choice about the conditions into which we are born; not skin color, degreee of physical impairment, intellligence, health, financial situation, location or opportunities in life etc. I don't like hearing gutter terms used about any minority because it reminds me of the hate behind the words.
Please find out the dangers to yourself, your loved ones, your customers and your wealth that you are inviting by making the repairs you have discussed. Tom