Exactly where did the oil shoot out of?

 

Can you expand on what you mean by

"...came shooting out on the brake mounts front and back"

At the lever/shifter end?
At the caliper end ?
Where precisely ?

Was the wheel in At the time? And pads installed?
(I ask in case they squeezed the brake levers without pads or rotor in case that they did was squeeze up with those missing - in which case the pistons can over-extend and pop out. That would defo pish oil everywhere!)

Luckily the shimano mineral oil isn't as bad on paintwork than DOT4 or DOT5 as used on several other manufacturers (and in cars). But you still want that off as soon as possible !!


Otherwise sounds like the hose wasn't connected and tightened fully or (depending on exact set up) a seal / O ring / olive was missing.

he pointed at the caliper ends, so I assume there.

don‘t know about wheels and pads installed during brake bleed and brake test.
he showed me the bike without wheels and pads installed.
i‘d assume a mechanic would know not to squeeze brakes without wheels/rotors installed.
the video showed those yellow bricks to install during bleeding process, don‘t know if he did do that.

as I didn‘t fuzz with the hose on the caliper end and for the bleeding process there is no need for the mechanic to do so, this shouldn’t be the cause. the brakes worked fine before changing the levers.

so you say the pistons can actually shoot out, meaning that the hose on the caliper end is basically open. that would explain a lot.

as for which oil he used: i am not sure that a mechanic that might hit the brakes without wheels/rotors installed knows which oil to use for a shimano hydraulic brake. i basically lost all trust.

see post above, he pointed at the caliper end, while showing me the bike without wheels and pads installed.

It sounds like the mechanic didn't show you exactly where the oil came out.

You should call and ask.

I think you need a new LBS.......LOL

Jeroen

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Owner at TRIPRO, The Netherlands

that‘s top priority on hobby to do list.

thing is, I called a couple of LBS and they would give me an appointment in three weeks to do a full break bleed.

nope he didn‘t. he kept the bike to fix it.
but as said, i lost all trust.

i noted some questions for thursday (where did the oil come out, where wheels, discs, and pads installed while you did the test, did oil go on discs or pads, which oil did you use).

but as a novice i shouldn‘t be asking those questions. i give my bike to a LBS because I am willing to pay for expertise and know how that I don’t have. i want him to solve problems I can‘t. and not get a bigger problem back that I then solve through the knowledge of this forum and give him the solution.

i mean, don‘t get me wrong I‘ll share the knowledge with him, but next time I‘ll just do it myself through your help.

I forgot to mention... when your mechanic caused mineral oil to squirt on the brake pads, the brake pads were contaminated and have to be replaced.

Thanks.
that is part of my questionaire as I am aware of contaminated pads and rotors.

I just hope it was a brake push without wheels and pads installed that caused the spill.
Stupid but no damage done (hopefully!).

The rotors don’t absorb oil, so they can simply be cleaned with alcohol or acetone.

Thanks, good to know.

Could he broke a valve or popped a seal when he pushed the brakes hard? ( front and rear at the same time? What‘s the chances?)
Or is the most obvious thing pistons shooting out causing oil to spill?

Squeezed the lever without the pads or a rotor in place and forced the pistons out of their bores? hilarity and escaped oil ensues?

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Andy Tetmeyer (I work at HED)

So just to not give you mechanic a beating without them being able to reply here...
- you mentioned the yellow brick spacer. That's good if used. That's exactly what should be used (with wheel off and pads out - the brick fills the space and ensures no contamination of rotor or pads, as they are out.)

For pulling the levers without rotors or pads or wheel. It can happen some times - just an inadvertent or 'auto reaction'. I've done it myself when getting the mtb in or out of the car with the front wheel out. (Never popped a piston out though). Usually accompanied by a 'feck' or 'bollox' half a second after I did it. Just had to prise the pads apart to get the wheel in after.

Seal failure can occur. Tho at 2 ends at once seems unlikely.

If it wasn't the missing wheel / pads, the 2nd thought I'd have is that the bleed nipples on the calipers weren't fully done up after doing the bleed. If for example they were only just nipped up a smidge whilst still doing stuff, then missed tightening properly.

I've seen plenty of total feckups from fitting errors in my near 30 years in transportation - even a BA pilot has been half way out of a missing cockpit windscreen in the air after some eeeejit didn't put the right size bolts in the window frame 😖 a few years ago.
Closer to home, from a reputable local bike shop one of my mates took delivery of a new Santa Cruz blinged up full suss mtb a few years ago at an eye watering price ... 1st ride out I passed him near the end of the 1st decent. He didn't look happy. Stopped, waited for him...Bolts holding the caliper to the rear frame... missing.
Then checked the other caliper.... the bolts were finger tight at best.

i‘m waiting for his answers. maybe there really is something broken and he saved me from a fatal accident by discovering it through his test.

i mentiones the bleed blocks because I saw them in a video. I don‘t know if he used them. ut I assume you couldn‘t do the brake test with them installed.

and yes, I had situations as well where I put the bike on the trainer and then pulled the lever. nobody is free of mistakes. but again my expectations towards a professional are different than to a novice.

bleed nipples was my guess as well. maybe overtightened and broken or not tightened enough.

If I read your initial post correctly, you installed the brakes, hoses, and levers. The only thing you took the bike in for was the bleeding. Is it possible the hose didn’t seat properly in the caliper?

I'm trying to learn all this stuff for the first time, watching videos etc. The above, or similar sounds most likely. The mechanic obviously did the same mistake front and rear. Is it possible he left off the 'olive' and thus lost the seal on the connection??

If all he did was bleed the brakes, he wouldn’t have touched the olive. The bleed nipple is separate. To me, it sounds like the olive wasn’t fully crushed/seated on install.

I only installed the levers.
Hoses were installed, brakes as well. Didn‘t need to touch them because I had hydraulic mechanical ultegra installed. Just needed to change levers (unplug hose from that lever and plug into new levers). So would have understood if the oil shot out of the levers, then I would have done something wrong. But as the bleeding went ok and oil actually showed up in the cup on the lever during the bleeding process the flow of the liquid from the brakes to the levers was possible.

As brakes worked fine before I gave it to the LBS and like you said, the mechanic wouldn‘t need to touch them at the brake end, I hardly see olive/seals on the brakes not being installed properly being the issue.

Yep, my assumption was they had been recently installed.

We're the hydraulic hoses long enough for the new installation?

This sounds likely.

Also a possibility - and I know, because it happened to me - could have a cracked piston that hydraulic pressure kept in place until it didn't during the bleed process, at which point the crack became evident, and there was suddenly fluid every g-damn where when pressure was reapplied.

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Tech writer/support on this here site. FIST school instructor and certified bike fitter. Formerly at Diamondback Bikes, LeMond Fitness, FSA, TiCycles, etc.
Coaching and bike fit - http://source-e.net/ Cyclocross blog - https://crosssports.net/ BJJ instruction - https://ballardbjj.com/

Ok, sounds like a possibility as well.
Likelihood of happening front and back at the same time is probably rather low I guess?

Will pick up tomorrow and share with you all the story.