I replaced my track rod and drag link with the set from Terrafirma. On the OEM all rubber boots except the boot at the drop arm were shot. My steering box is leaking which oils this rubber boot well. It looks like new and I wonder if it's a good idea to treat all rubber boots with PS fluid in general. Or is there a better fluid to do that?

 

Wintergreen oil. It's commonly used on bikes to treat old rubber to keep it pliable. Some people even put a couple of drops inside the tyre via the valve stem.

 

@mollusc Thanks for the hint. I did some research. Winteroil is methyl salicylate chemically and commercial products use that in their products, like "Rubber Renue".

https://mgchemicals.com/products/ele.../rubber-renue/

Edit: just read in the safety sheet Rubber Renue is 73% isopropyl alcohol and 27% methyl salicylate. Probably cheaper to buy the ingredients and mix own solution.

 

The isopropanol is used as a solvent to help the wintergreen penetrate the rubber. It evaporates pretty quickly, leaving the oil behind. Personally I use xylol instead.