seized formula brakes

gthang

Hi Guys, not posted for a while, i hope someone can point me in the right direction.

Before I say anything else, i've tried searching for my subject title (and variations of) and couldn't find any answers, even though I sure this will have been asked before, so apologies for the repetition. (perhaps I've searched badly?)

Anyway;

I've taken my Cube Ltd race (2008) out of the shed after the winter, not been used in 5 months. Unfortunately the rear formula oro K18 brake has partially seized on. It's not totally locked on, however it's quite stiff when turning buy hand.

My question is; will a bleed sort this out? our could it be something else, as the front brake is fine?

Thanks for any advice.

cooldad

Bleeding won't achieve anything. Take it for a short ride and see if it loosens up.

nicklouse

push the pistons home and reset them. go ride.

gthang

thanks, sound promising, i'll try to take if for a spin after dinner, if not tomorrow evening.
i'll let you know how it goes.
cheers

gthang

still struggling here, went for a ride a couple of weeks ago as suggested = no improvement.

work / life commitments have prevented me riding for the last couple of weeks. Got the bike out today and the rear brake is now locked more or less solid with very little moment in the brake leaver.

I've managed (with some difficulty) to remove the rear wheel and then the brake pads. I can't push the calipers back.

has moisture got in the brake fluid?
does this now mean the brake needs bleeding? what do I need to do?

nicklouse

sounds like a bleed is needed as nothing else have worked.you need a Formula/avid bleed kit. See the FAQs about making a home made one.

download the bleed info from formulas Webby and watch out for the O rings.

adebisi

[thread hijack]

A week back, I was riding when my Formula Oro K18 rear brake suddenly began to rub. I squeezed to brake lever a couple of times to see if that would help only to have my brake seized almost completely. As emergency fix, I removed the wheel and pushed the pistons back with a screwdriver and rode back home without touching the brake lever even once.

Next day I started to investigate the matter only to find out that the brake worked just fine. I deemed that there must have been some ice somewhere inside the calliper which caused the brake to get stuck. And now that the bike had been in warm storage, it had melted. (FYI, I ride in arctic winter with temperatures ranging from +2 degrees Celcius down to -25C). In the end, I did nothing since everything seemed to work just fine.

And it did until today. The brake got stuck again.

My initial guess is that there is some moisture in the system which freezes and occasionally prevents the pistons from retracting. If there's moisture in a closed system, it means that there must be a leak. Hence, I think that bleeding the brakes won't be enough, but the seals have to be replaced, too. Now the problem is that I do not know the exact location of the leak and it must be extremely small anyway because most of the time the brake works just fine. This forces me to replace all O-ring seals which normally wouldn't be a big deal. However, it seems that Formula sells the O-rings only together with other hardware bits that are quite expensive. Actually, I could get completely new brakes for the same price.

Hence, my question is:
Does anyone know whether Formula sells an universal/generic O-ring only kit that includes all the necessary sizes for complete maintenance (for Formula Oro K18s)?

[/thread hijack]

nicklouse

http://store.formula-brake.com/spare_parts/oro/calipers

sounds like they need a full service.

adebisi

nicklouse wrote:

http://store.formula-brake.com/spare_parts/oro/calipers

sounds like they need a full service.

That's the very site where I searched for the spare parts. There's the O-Ring kit FD40060-10, but I don't know is that alone (or several of them) enough for a full service. The exploded view of the brake identifies several small parts that include an O-ring. If you bought all those small parts separately, you'd end up spending more cash servicing your old brakes than replacing them completely would cost. And it is only the rubber seals you need.

I've asked Formula customer service for advice but haven't got an answer so far. Thus, I decided to ask you guys, if someone would know the answer?

adebisi

adebisi wrote:

The exploded view of the brake identifies several small parts that include an O-ring. If you bought all those small parts separately, you'd end up spending more cash servicing your old brakes than replacing them completely would cost. And it is only the rubber seals you need.

Exploded view http://www.formula-italy.com/documents/834

From that, I've been able to decipher that for a full service you'd need (=parts with rubber seals/O-rings)

Hoses
Hose joint kit (FD40011-40)

Master Cylinder
Piston kit (FD40065-20)
Stop piston kit (FD40070-20)
Screw reservoir kit (FD40049-20)
Hose screw kit (FD40074-20)

Calliper
O-ring kit (FD40095-10)


That sums up to a total of ~65euros for one end (=130euros for front+rear). And that doesn't event include the calliper nor the master cylinder bodies, brake pads nor the discs. Not to mention the bleeding kit and brake fluid. If that's the price you have to pay while you can get a brand new complete front+rear set for ~150euros, I see little sense servicing your brakes.

I believe it would be whole different story, if you could get all the necessary O-rings separately.

nicklouse

then take the old ones down to your local Hydraulic specialist.

adebisi

nicklouse wrote:

then take the old ones down to your local Hydraulic specialist.

Might be I'll do just that. Or order the O-rings on the internet myself...
I believe EPDM O-rings are suitable for brake applications. Any objections?

Formula recommends DOT 4 brake fluid to be used. However, I was wondering whether I could change to DOT 5, so that I wouldn't have to worry about water condensating into the system?

But let's wait for the answer from Formula before I make any moves.

mrmonkfinger

you can't mix dot 5 with dot 4.

bad things will happen

you can use dot 5.1 if you want, as that is compatible

http://en.wikipedia.org/wiki/DOT_4

nicklouse

adebisi wrote:

nicklouse wrote:

then take the old ones down to your local Hydraulic specialist.

Might be I'll do just that. Or order the O-rings on the internet myself...
I believe EPDM O-rings are suitable for brake applications. Any objections?

Formula recommends DOT 4 brake fluid to be used. However, I was wondering whether I could change to DOT 5, so that I wouldn't have to worry about water condensating into the system?

But let's wait for the answer from Formula before I make any moves.

DOT5 is the worst fluid out there.

Water is not a problem in 4 or 5.1 but is a BIG issue with 5 as it does not mix it just sits there and rusts and freezes.

I would say the brakes just need a clean and a sort.

you do clean them each time you change the pads dont you.

adebisi

mrmonkfinger wrote:

you can't mix dot 5 with dot 4.

bad things will happen

you can use dot 5.1 if you want, as that is compatible

Mixing fluids was not in my mind. I would've flushed the system clean first (do not know exactly how but there must be way =D).

nicklouse wrote:

I would say the brakes just need a clean and a sort.

you do clean them each time you change the pads dont you.

I was just wondering whether DOT 5 would provide an improvement...

Cleaning is a no brainer. I'm pretty sure that the problem is moisture related, since both times, a few hours in a warm carage has provided the remedy. The stiffening of the brake lever also suggests some phenomena other than crap hindering the calliper piston/pad movement. However, I'm not a specialist and these are all but wild guesses.

Northwind

DOT 5 is pish. Not literally, but.

I think Formula might recommend only Dot 4. I use 5.1 in mine anyway, and it's fine.

As for that refurb- not sure it'll be worth it, you can pick up good condition Oros for around £75 a pair now and that'll give you a load of spares too. Personally I'd give them a full strip and clean and rebuild, see if that works, if not I'd replace rather than throwing significant money at them. It'd obviously be spammy of me to mention I have 3 sets for sale

adebisi

Northwind wrote:

As for that refurb- not sure it'll be worth it, you can pick up good condition Oros for around £75 a pair now and that'll give you a load of spares too. Personally I'd give them a full strip and clean and rebuild, see if that works, if not I'd replace rather than throwing significant money at them. It'd obviously be spammy of me to mention I have 3 sets for sale

My sentiments exactly. It's much cheaper to buy just the O-rings from your local hydraulic specialist. They sell the same stuff but you don't have to pay anything extra for stuff you do not need. And besides, owning more than one set of brakes actually adds to redundancy. You can always have one set in maintenance and one in use, which is great for people who need their bike every day.

I already managed to find a good bargain on a brand new set.

stubs

Even if you clean your brakes like a surgical theatre you still cant use DOT 5 its silicone based fluid and it will do nasty things to your brakes internals and leave you with no brakes and leaks everywhere. Plus its an absolute swine to bleed as unlike DOT 4 or 5.1 the fluid absorbs air. It was designed for military vehicles because it doesnt catch fire like other hydraulic fluids.

ilovedirt

My Megas siezed up, professional WC mechanic couldn't get the pistons to budge so i sold them as spares and bought some shimanos...