quick question, what fluid for a Pro-stop disc brake?

[My_Teenage_Self]

I've already replied to Phil, but as above, MC used ATF. Most people started using Magura royal blood... I suspect you'll find them full of lovely bright green LHM +...

 

[My_Teenage_Self]

I'd also add, they are an absolute bastard to bleed, you need to bleed them every 3 weeks, and the levers need a low leverage ratio, similar to V levers. Paul Smith used Avid ulitmates for this exact reason. normal Canti levers will result in a very mushy feel.

 

[jonnyboy666]

hey gents,

thanks for all the replies, tried the bleed using royal blood from magura, yes, utter bar-steward, i get hardley any pressure or borderline locked on, any tips? i am using the official from mountain cycle instructions by the way!

 

[joglo]

adding @coyut, he was dealing with ProStop a while ago, and has put together the nice Mountain Cycle documentation
https://www.retrobike.co.uk/archive/history-of-mountain-cycle.1274/maybe he has still some good recommendations?

 

[Shorge]

Hi Guys
I hope my information helps and hope you could help me out too.
recently bought a Gary Fisher RS-1 with Pro Stop Brakes at an auction.

View attachment 874982


To my surprise, it came with a bottle of "Pro-Stop Hydraulic Brake Fluid".



So I've did a simple test by dropping water in to
1. SHIMANO HYDRAULIC MINERAL OIL
2. FINISH LINE BRAKE FLUID DOT 5.1
3. PRO-STOP HYDRAULIC BRAKE OIL

Here's what happened.



Pink circle = SHIMANO Mineral Oil
Red circle = PRO-STOP Brake Fluid
Black circle = FINISH LINE DOT 5.1

The drop of water on the oil has no affinity with SHIMANO Mineral and PRO-STOP while Finish Line DOT 5.1 has.

Therefore, I suppose PRO-STOP use Mineral Oil that has no affinity with H2O that is. something similar to SHIMANO.

(well that is if this bottle was not refilled by the last owner... )

What do you think guys?
Lemme know if there should be any other tests that I could try
so we can finally identify the best existing Brake Fluid that matches Pro-Stop Mountain Cycle brakes!

 

[coyut]

ProStop brakes came with Buna-N seals and used mineral transmission oil, silicone-based oils, but did not work with DOT
More info can be found in my MC doc, which is linked further up.
You'll need to change sealings if you want to use dot.
Specs on the seals are also in my doc.

The info in my doc was supplied by Robert Reisinger.
Designer of the brake.

 

[bikeworkshop]

Peak Pandemic we used citroen LHM for mineral oil hydro brakes.
This was after extensive research that I can fortunately no longer remember.
Shimano brake oil was o/s for ages.

Everything worked and no- one came back with seals gone.