If someone bled Hope E4's with mineral oil instead of dot5.1, will the hose need to be changed after all the seals and diaphragm have been replaced?
Asking for a friend (really, I am)
I dont think so. It's the other way round I believe your friend has a problem.
It will need a good flush to make sure any remnants of mineral oil are gone. I think the other way ruins the seals but suspect it won't be ideal.
So a flush through and then a bleed should be good.
He's doing diaphragms, master pistons, caliper seals and bore cap o-rings.
Stripping everything down, flush with IPA, then water, then 5.1. Rebuild, bleed.
He managed Inners with both front and rear with mineral oil in... Only after did the front stick as the seals had swollen. He should buy a lottery ticket.
Hoses should be okay but if he's got that much work to do one the brakes, I'd change the hoses anyway.
The inner part of the hose is Ptfe so it'll be fine 😉
It’s the other way round I believe your friend has a problem.
Mineral oil in DOT brakes will destroy seals. Either way round is bad news.
Oh he ****ed the seals alright. I told him to get new hoses just in case.
When I was working in the bike shop I had someone come in with a peculiar rear brake set up. He had a Shimano lever with an Avid calliper.
He was a bit miffed when I said I wouldn't bleed them. He said he's been riding like that for a year without issue but didn't know if the fluid used was mineral or DOT but he thought it was probably mineral.
So it seems like at least one combination of wrong fluid can last for a year but I wouldn't like to try it myself.
Long time ago when I worked in a bike shop, a chap came in with a Trek Y bike fitted with Hayes brakes. He was most miffed that the previous bike shop had bled his brakes with Magura mineral oil.
All the seals I took out if those brakes were like warm licorice.