I recently did a full rebuild of my ROs. A lot of info on them I find is fairly scattered or not specific so hopefully this'll give a hand to anyone googling how to service them.
Most of this was told to me by users here. I forgot to take pics of replacing seals, sorry.
Overview
They're Good brakes, fully serviceable with pretty easy to find spare parts. Might not be the most powerful but they make up for it with reliability.
Calipers before 2013 had less piston movement - Brake rub and caliper seal wear affect them more.
The old style (2011 - 2014) master cylinder isn't the best for people with small hands, It's hard to get the lever close to the bar. The 2015 RO Racing MC is better.
Removing the FCS / Bite point adjuster can make the brake feel better.
Here's an exploded diagram and part numbers
http://www.rideformula.com/wp-content/uploads/manuals/en/766
I got best results following formula's bleed guide
Where to buy parts (Europe)
Bike24, bike-componenets.de , Probikeshop, Silverfish and ebay seller KW570 are what I used and they have pretty much everything.
formula also have an online shop for spares but I haven't had luck finding RO parts there,
http://store.formula-brake.com/spare_parts
Pads
Formula's own sintered pads are probably the best. A decent cheap alternative is uberbike sintered pads.
Wear parts & Troubleshooting
Caliper piston seals. Probably the most common wear part.
I noticed less power, sticky or seized pistons, leaking/excess fluid on pistons and brake rub.
Part number FD40170-10
Kit costs about 20 eur for 1 caliper. Doesn't include grease
Sometimes you can fix sticky pistons by popping them out and greasing them, but if you've been using the brakes hard and get problems it's probably best to replace the seals.
Barb O-ring. Formula brakes in general can leak here.
Usually means mushy levers, air always getting in and bleeding not really doing anything.
Either replace the barb & fittings or install Hayes one piece Olive/barbs which have been more reliable for @Udi
Master cylinder piston (rarely fails, but mine did)
Signs include brake fluid on the plunger shaft,dust seal & reach adjust parts. I noticed mushy and inconsistent lever feel. It looks like age and dirt getting inside can damage the master cylinder piston O-ring.
Kit costs also about 20-25 eur for 1 MC. Includes grease
Master cylinder diaphragm (also rarely fails)
Bad diaphragm usually means brake losing all pressure or leaking constantly from the rear vent hole.
If you're aggressive with bleeding they can get a bit dislodged from the recess they press in to. Might be worth giving it a clean and pressing it back in if you get tiny occasional leaks from the vent hole
Lube me up
The best grease to use on DOT brakes is PFPE. This is some mad shit that lasts long and is expensive.. The 3 grams that came with the master cylinder kit was enough for both my brake rebuilds. You don't need a lot of it.
Usual brake grease like red rubber grease is fine too, it just won't last as long on the caliper pistons
Caliper Piston seal replacement
-Take the caliper off the bike, brake pads out, etc. everything is going to get covered in oil so use a tray or something. Clean the fuck out of the caliper
-Stick a mostly filled syringe in the caliper bleed port.
-Tie wrap one of the pistons down, push the syringe and pop out the piston.
-Take off the syringe and the old piston seal. Clean everything thoroughly with alcohol. Clean the piston, smear a good bit of grease on it and set it aside.
the hardest part is getting that bastard seal in. I usually got it in by pinching the sides and stuffing it in through the bottom of the caliper.
Once it's in, stick the freshly greased piston back in and repeat for the other.
Bleed the brake- after pushing fresh oil through to the MC, lightly push down the brake lever and lightly pull suction on the caliper syringe. Some bubbles should come out. I found I needed to repeat the bleed procedure to get the best results.
Master Cylinder / Lever Rebuild
Best to take it off the bike and drain it. You need 2 3mm allen keys, a 2mm allen key, a seal pick and circlip pliers (like these) https://proxy.duckduckgo.com/iu/?u=https://media.autoteile-werkzeuge.de/Artikelbilder/760px/n-bgs432-3.jpg&f=1
The exploded diagram is useful here because I didn't take pics.
http://www.rideformula.com/wp-content/uploads/manuals/en/766
To get the lever out of the way:
Put the reach adjust all the way out. Put the 3mm keys in both of the lever pivot bolts. (Part nos.11 in diagram)
Unscrew one of them. You should see the lever pivot axle (part no.10), and there's a hex cut into it - Stick a 3mm allen key in there, and you should be able to unscrew the other bolt and move the lever.
Careful not to round off anything here, the hexes are delicate and there's a lot of blue loctite about
Next, use the 2mm allen key to undo the tiny screw on the lever(part no.24) Careful - there's a spring and ball here (parts 21 & 22) . Try to pop them out and set them aside along with the little clamp (part no.23). Then turn the reach adjuster out until your lever comes off the plunger (part no.6) and threaded part (part no.20)
Note the orientation of all the small parts here, there's a specific way they go together, particularly the little clamp (23) and the threaded part (20) that goes onto the plunger
You can take off part 20 for cleaning by popping off a spring, and a pin should slide out (part 25). It can get a bit rusty, to pop it out you can stick that same spring and jam it gently into a tiny hole opposite of the pin.
MC internals
Now you can pry out the dust seal (part no.12) and get at the MC bore cap (part no.5) . Use your circlip pliers to unscrew it. It's going to be tight and loctited so push down hard.
Once that's off you can take off the plunger (6) and take out the MC piston and spring.(4,14,15) There's also another seal inside the MC (3). It is not pressed in. Note the orientation of it (it has a flat side and lip side. Lip side should be facing up out of the MC) and lift it out.
On the other side of the MC is the diaphragm cap. use your pliers to push down hard and rotate the cap 90 degrees, then pop it off with your fingers.
Give everything a good clean and greasing. Grease the MC piston O-ring well and put a little bit on the inside face of the internal seal (part no.3)
Reassembly is the reverse of disassembly ))) I found it fairly straight forward, just be careful and take it slow when doing stuff life this for the first time
Most of this was told to me by users here. I forgot to take pics of replacing seals, sorry.
Overview
They're Good brakes, fully serviceable with pretty easy to find spare parts. Might not be the most powerful but they make up for it with reliability.
Calipers before 2013 had less piston movement - Brake rub and caliper seal wear affect them more.
The old style (2011 - 2014) master cylinder isn't the best for people with small hands, It's hard to get the lever close to the bar. The 2015 RO Racing MC is better.
Removing the FCS / Bite point adjuster can make the brake feel better.
Here's an exploded diagram and part numbers
http://www.rideformula.com/wp-content/uploads/manuals/en/766
I got best results following formula's bleed guide
Where to buy parts (Europe)
Bike24, bike-componenets.de , Probikeshop, Silverfish and ebay seller KW570 are what I used and they have pretty much everything.
formula also have an online shop for spares but I haven't had luck finding RO parts there,
http://store.formula-brake.com/spare_parts
Pads
Formula's own sintered pads are probably the best. A decent cheap alternative is uberbike sintered pads.
Wear parts & Troubleshooting
Caliper piston seals. Probably the most common wear part.
I noticed less power, sticky or seized pistons, leaking/excess fluid on pistons and brake rub.
Part number FD40170-10
Kit costs about 20 eur for 1 caliper. Doesn't include grease
Sometimes you can fix sticky pistons by popping them out and greasing them, but if you've been using the brakes hard and get problems it's probably best to replace the seals.
Barb O-ring. Formula brakes in general can leak here.
Usually means mushy levers, air always getting in and bleeding not really doing anything.
Either replace the barb & fittings or install Hayes one piece Olive/barbs which have been more reliable for @Udi
Master cylinder piston (rarely fails, but mine did)
Signs include brake fluid on the plunger shaft,dust seal & reach adjust parts. I noticed mushy and inconsistent lever feel. It looks like age and dirt getting inside can damage the master cylinder piston O-ring.
Kit costs also about 20-25 eur for 1 MC. Includes grease
Master cylinder diaphragm (also rarely fails)
Bad diaphragm usually means brake losing all pressure or leaking constantly from the rear vent hole.
If you're aggressive with bleeding they can get a bit dislodged from the recess they press in to. Might be worth giving it a clean and pressing it back in if you get tiny occasional leaks from the vent hole
Lube me up
The best grease to use on DOT brakes is PFPE. This is some mad shit that lasts long and is expensive.. The 3 grams that came with the master cylinder kit was enough for both my brake rebuilds. You don't need a lot of it.
Usual brake grease like red rubber grease is fine too, it just won't last as long on the caliper pistons
Caliper Piston seal replacement
-Take the caliper off the bike, brake pads out, etc. everything is going to get covered in oil so use a tray or something. Clean the fuck out of the caliper
-Stick a mostly filled syringe in the caliper bleed port.
-Tie wrap one of the pistons down, push the syringe and pop out the piston.
-Take off the syringe and the old piston seal. Clean everything thoroughly with alcohol. Clean the piston, smear a good bit of grease on it and set it aside.
the hardest part is getting that bastard seal in. I usually got it in by pinching the sides and stuffing it in through the bottom of the caliper.
Once it's in, stick the freshly greased piston back in and repeat for the other.
Bleed the brake- after pushing fresh oil through to the MC, lightly push down the brake lever and lightly pull suction on the caliper syringe. Some bubbles should come out. I found I needed to repeat the bleed procedure to get the best results.
Master Cylinder / Lever Rebuild
Best to take it off the bike and drain it. You need 2 3mm allen keys, a 2mm allen key, a seal pick and circlip pliers (like these) https://proxy.duckduckgo.com/iu/?u=https://media.autoteile-werkzeuge.de/Artikelbilder/760px/n-bgs432-3.jpg&f=1
The exploded diagram is useful here because I didn't take pics.
http://www.rideformula.com/wp-content/uploads/manuals/en/766
To get the lever out of the way:
Put the reach adjust all the way out. Put the 3mm keys in both of the lever pivot bolts. (Part nos.11 in diagram)
Unscrew one of them. You should see the lever pivot axle (part no.10), and there's a hex cut into it - Stick a 3mm allen key in there, and you should be able to unscrew the other bolt and move the lever.
Careful not to round off anything here, the hexes are delicate and there's a lot of blue loctite about
Next, use the 2mm allen key to undo the tiny screw on the lever(part no.24) Careful - there's a spring and ball here (parts 21 & 22) . Try to pop them out and set them aside along with the little clamp (part no.23). Then turn the reach adjuster out until your lever comes off the plunger (part no.6) and threaded part (part no.20)
Note the orientation of all the small parts here, there's a specific way they go together, particularly the little clamp (23) and the threaded part (20) that goes onto the plunger
You can take off part 20 for cleaning by popping off a spring, and a pin should slide out (part 25). It can get a bit rusty, to pop it out you can stick that same spring and jam it gently into a tiny hole opposite of the pin.
MC internals
Now you can pry out the dust seal (part no.12) and get at the MC bore cap (part no.5) . Use your circlip pliers to unscrew it. It's going to be tight and loctited so push down hard.
Once that's off you can take off the plunger (6) and take out the MC piston and spring.(4,14,15) There's also another seal inside the MC (3). It is not pressed in. Note the orientation of it (it has a flat side and lip side. Lip side should be facing up out of the MC) and lift it out.
On the other side of the MC is the diaphragm cap. use your pliers to push down hard and rotate the cap 90 degrees, then pop it off with your fingers.
Give everything a good clean and greasing. Grease the MC piston O-ring well and put a little bit on the inside face of the internal seal (part no.3)
Reassembly is the reverse of disassembly ))) I found it fairly straight forward, just be careful and take it slow when doing stuff life this for the first time
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