Formula Brake Bleed Kit O Ring Help please

Zac Hinton

Zac Hinton

St Bernard
Just did a bleed on my Formula The One brakes. Very unsuccessful, as I have discovered my bleed kit is missing a little o ring that fits over the part that threads into the bleed port. When pulling back on the master cylinder syringe it was sucking air in like crazy. All done and lever pulls in all the way to the bar with barely any brakes.

So my question is, this o ring I'm missing, does it need to be anything special or do I just go to a bearing/seal place with the syringes and get something that fits?

I think they might have had them before when I used them on my last bike which had Formula Oro brakes, but maybe they got in the way.
 
Boom King

Boom King

downloaded a pic of moorey's bruised arse
Any o ring of the right diameter will be fine. Check the plumbing section of your local hardware.
 
Zac Hinton

Zac Hinton

St Bernard
Boom King said:
You could even use the ring off the bleed port screw.
Click to expand...
That one is a bit small, as it looks like it contacts against the angled tip of the bleed port screw rather than fit over the thread. I hope no one sees my car parked in the interim with a massive syringe sitting in the console!
 
T

tommy gun

Likes Dirt
Try using thread tape

Zac Hinton said:
Just did a bleed on my Formula The One brakes. Very unsuccessful, as I have discovered my bleed kit is missing a little o ring that fits over the part that threads into the bleed port. When pulling back on the master cylinder syringe it was sucking air in like crazy. All done and lever pulls in all the way to the bar with barely any brakes.

So my question is, this o ring I'm missing, does it need to be anything special or do I just go to a bearing/seal place with the syringes and get something that fits?

I think they might have had them before when I used them on my last bike which had Formula Oro brakes, but maybe they got in the way.
Click to expand...
 
John U

John U

MTB Precision
Zac Hinton said:
That one is a bit small, as it looks like it contacts against the angled tip of the bleed port screw rather than fit over the thread. I hope no one sees my car parked in the interim with a massive syringe sitting in the console!
Click to expand...
Could you use the one off the bleed port screw on the lever?
 
Flow-Rider

Flow-Rider

Burner
Go to a bearing place and ask for a O-ring that is suitable for brake fluid. You can use normal O-rings, it just means that the next time you go to use them they may be a bit stretched. Formula brakes are a prick to bleed, unfortunately worse than Avids. The bleed port on some of them is actually in the outlet port of the hand piece, so its very hard to get all of the air out of the piston area.from.jpg
 
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sufferthesinglespeed

sufferthesinglespeed

Likes Dirt
Are a pain in the ass to bleed properly, I was taking them off and attaching them on the opposite side so the bleed port was on the outside of the bar.
Worst design ever.
I did bleed them using my Avid bleed kit though, worked well enough. But there is a dead spot in the lever stroke when bleeding, feel it just give out and lose pressure and no amount of faffing about could stop it happening.
Swapped them out. Shimano are easy, even the Avids were easier.
 
G

gregp

Likes Dirt
I've had no problems bleeding my Formula R1 brakes. It was a breeze. Much easier than my Avid Elixir CRs. Just make sure you follow the instructions and position the MC so the hose and bleed port point up.

The diagram above is not accurate. On The Ones the bleed port is next to the hose outlet but they both point in the same direction, opposite to where the leaver is pointing. When doing the bleed, make sure the lever is pointing down. My R1 bleeds are so easy I thought they were fool proof and Avid was a poor imitation. The levers are always rock hard after the bleeds.

The O ring is 1x4mm. For DOT4 compatibility you need EPDM type (Ethylene - Propylene) not the common nitrile NBR / N / Buna-N type. Seal Imports in Springvale have the EPDM 1x4mm in their catalog but ring first to confirm stock as normally they just carry the N type. Or just get a bunch of nitrile ones and change them when they swell.

Personally I'd stay away from plumbers tape, it tends to get torn to shreds during install/uninstall and it could clog up your ports.
 
Flow-Rider

Flow-Rider

Burner
gregp said:
The diagram above is not accurate. On The Ones the bleed port is next to the hose outlet but they both point in the same direction, opposite to where the leaver is pointing. When doing the bleed, make sure the lever is pointing down. My R1 bleeds are so easy I thought they were fool proof and Avid was a poor imitation. The levers are always rock hard after the bleeds.
Click to expand...
Incorrect! It's the exact diagram from a C1. Don't know what the OP has because he hasn't stated but the R1s are easier to bleed, totally different set up.

C1.jpg
 
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Flow-Rider

Flow-Rider

Burner
gregp said:
I think you need to re-read the OP. He said he has The Ones. Same config as R1. But the point we're arguing is kind of irrelevant to his query anyways...
Click to expand...
Sorry slap me! Thought he meant the one series. Didn't know they ' The One ' existed until you said it.
 
No Skid Marks

No Skid Marks

Blue Mountain Bikes Brooklyn/Lahar/Kowa/PO1NT Raci
The diagram is a new budget brake released last year, all the Ro, R1, The Ones etc bleed much the same, even the new R1 Racing. Anyway, doing the gentle syringe master cylinder pull up and release several times while changing angle of bike would no doubt get the air out of those C1s in diagram.
Avid bleed kit might need knurled bit filed down, to use, depending on what brake, but the Ones I think it does.
Thanks for the o'ring info gregP
 
Zac Hinton

Zac Hinton

St Bernard
Went to Geelong bearing place and picked up 1x4mm o rings as recommended and it fit well on the Formula syringe kit. They didn't have the EPDM type so just have to replace them often if they swell. At 20cents a pop it doesn't pose a major problem. Thanks for all the input guys
 
T

The Fallen

Cannon Fodder
thanks gregp, i had just ordered 50 1x (ID)2 and now they've arrived i can see they are far too small now.


my verniers (only just arrived) measure the grub screw (shaft inside the thread) at 3.8, so the 4mm as your pic shows it is.
 
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