Softening Rubber with Brake Fluid

[Skywatcher]

Greetings All

On several posts in the technical forum, I have read about using brake fluid to soften rubber parts. Does anyone know if brake fluid would work to soften the natural rubber on a vintage typewriter platen? Yes, I collect and recondition vintage manual typewriters and the one common ailment these machines suffer is a rock hard platen. I've had a few platens re-covered by a rubber specialist in Fairport, NY, but that gets a little pricy when you want to get half a dozen or more done. Any thoughts or ideas more than welcome,

Sky

[KE4AVB]

Sky. I work as a tech at a local office supply business for 8 yrs and we never tried it as we always had the old typewriter platens recovered. I was on the calculator side of the repair shop and I only had my platens recovered too on the old mechanical Victor calculators. At that time it was reasonable to do it but I have been out that line of work since 1986.

When I worked for Standard Register (1986-1996) they never recovered their burst roll assembly due to round trip shipping costs and labor as the main reason. It was easier and cost effective to just manufacture new roll assemblies.

I do brake fluid will cause rubber to swell which will pressure problems for one thing and it might cause the rubber to continue to soften once applied. Much like 5 Dot brake fluid will destroy rubber parts in a 3 Dot brake system. I had it to happen to me once where the tire store put the wrong fluid in my master cylinder. I was lucky as I had a split master cylinder and only lost the front brakes. Still wasn't funny to slide through an intersection as a pickup rear brakes are nearly useless when you don't the weight in the bed.

[creia]

I first learned of this many years ago on an old Ford F-250 truck I owned. It was taking longer to go into gear and shift gears (automatic trans) and was getting worse. The vehicle was already high mileage and I knew it would need a new transmission in the very near future. My mechanic (I used him exclusively for over 35 years until he retired), said to add a small amount of DOT 3 brake fluid as it would soften and swell up the internal trans seals a bit, and I could get some more mileage out of the trans. I do not know how much brake fluid he added. He was right- The difference in shifting was immediately noticeable and improved and I drove that truck for 2 more years (probably at least 25K miles) until I eventually had the trans rebuilt. This was MY experience- as they say "your mileage may vary."
Sidebar comment/question: Sky, in your case what have you got to lose by trying it? You can still have them recovered if it does not work out.
Michael

[bobodu]

Sure would mess up paper for a good long time...

[KE4AVB]

Sure would mess up paper for a good long time...

Definitely don't want mess up a few thousand payroll checks. Bad enough when the machine was down due to a broken part.