New caliper seals the wrong size?

[marp68]

Are my new caliper seals the wrong size? See image, I've put the new on top of the old. The new is approx 3 mm wider than the old. Before contacting the seller I want to know if I missed something. I just can't get them to fit in the caliper.

I ordered them from Powerhouse Automotive in the UK. The are specialized in brakes and should know. The seals were labeled Yamaha 48mm brake caliper piston seals TZ250 TZ350 XS500 XS650 TX500 TX650 TX750. http://www.ebay.co.uk/itm/160922008038

 

[marp68]

I left them soaked in brake fluid for two nights according to a thread on the subject. Could they perhaps have swollen from that, even though brake fluid shouldn't damage them?

EDIT: I only used new DOT 4 fluid that was left in the old bottle (bought 1 year ago).

And btw, the old M/C piston seals didn't swollen.

 

[marp68]

I meausred them again. The thickness is the same as the originals, so the only difference is the diameter. If they had swollen, would they not have been thicker as well? This is why I think the size is wrong from the beginning. But I wanted to hear your opinions on rubbers possibilities to swollen in brake fluid, and in this case only regarding the diameter. I have contacted the company, so hope to hear from them soon.

Is there perhaps another xs650 48 caliper that uses slightly wider seals?

 

[marp68]

The company agreed to that the seals couldn't have swollen from the brake fluid. To sort things out and change the seals, they first wanted some images and measurements of the calipers, bore, grooves etc to establish that I have the correct ones for my model.

 

[marp68]

New seals

"Ok we are happy the calipers are correct for the seals but I need to point out that we sell hundreds of kits for bikes with these calipers using these seals and rebuild many sets in our workshop every month and we have never had an issue with them swelling, that said we have never soaked any overnight in brake fluid as this is unnecessary and bad practice. My resolution for this would be to send another set to you along with some specific rubber grease to rebuild the calipers or alternatively I am happy to offer you a full refund."

That's service!