MudLark Posted April 30, 2021 Author Posted April 30, 2021 Shimano mineral oil IS reddish pink. Glad you got the problem solved without having to replace hardware! Perhaps I misunderstood but the message was that the fluid that came out did not appear to be Shimano OEM fluid. I don't know. I have done brakes on cars more times than I care to count but never on a bicycle. Eldron 1
MudLark Posted April 30, 2021 Author Posted April 30, 2021 I could understand the paint shop possibly butchering the rebuild, but how is it that the LBS got it so wrong too.? Anyway, at least it's sorted without too much extra cost. Got what wrong? I don't think they got anything wrong. They simply said that they had a concern that there could be internal damage. I can only surmise that they have seen it before. Don't know. But as you say, problem solved and that's all that really matters to me!
Thomo Posted April 30, 2021 Posted April 30, 2021 Got what wrong? I don't think they got anything wrong. They simply said that they had a concern that there could be internal damage. I can only surmise that they have seen it before. Don't know. But as you say, problem solved and that's all that really matters to me!Unless I misunderstood, impression I got was that the problem persisted after having bike at LBS.?Thought they would have diagnosed and corrected the problem with first visit.
The Ouzo Posted April 30, 2021 Posted April 30, 2021 I certainly hope the paintshop did not use Dot3/4 fluid. Was it a bike paintshop or a general car panel shop ? ChrisF 1
DieselnDust Posted April 30, 2021 Posted April 30, 2021 the lever has an expansion bladder. That's the rubber cover that goes under the top cap of the reservoir.If that was refitted its impossible to overfill the system since fitting it will force any excess oil out of the system. I am assuming here that the fluid was injected into the system from the caliper bleed port back to the brake lever. MudLark 1
DieselnDust Posted April 30, 2021 Posted April 30, 2021 Looks like a complete system flush with Shimano OEM oil and cleaning some fittings has solved the problem. Some weird red pinkish fluid was found in the system. Some strange substance used as a kind of sealant also found in one of the passageway entrances. AS stated previously the Shimano OEM fluid is red/pink. The other stuff is likely red rubber grease used in hydraulic systems like brakes to lube the seals and fittings so that everything slides into place without pinching or rolling out of the seating grooves etc. I think your original problem was simply too much air in the system i.e. air bubbles MudLark 1
MudLark Posted April 30, 2021 Author Posted April 30, 2021 AS stated previously the Shimano OEM fluid is red/pink. The other stuff is likely red rubber grease used in hydraulic systems like brakes to lube the seals and fittings so that everything slides into place without pinching or rolling out of the seating grooves etc. I think your original problem was simply too much air in the system i.e. air bubblesThank you once again Diesel. Yes, I think you are right about the red rubber grease. The guy mentioned the word "red" and that they apply it to the nipples etc. I understood from him that they had found this had got into the system on the lever end. I will speak to the actual techie when I collect the bike. DieselnDust 1
thisismyotherbike Posted April 30, 2021 Posted April 30, 2021 Perhaps I misunderstood but the message was that the fluid that came out did not appear to be Shimano OEM fluid. I don't know. I have done brakes on cars more times than I care to count but never on a bicycle.If you've performed a bleed on a car a bicycle will be a breeze. You should try doing it yourself. I suspect some bike shops don't do a full bleed unless absolutely necessary, which ends up being a "go back to the shop a few times because I still need to pump the brake" type of exercise before it is done properly. ChrisF 1
droo Posted April 30, 2021 Posted April 30, 2021 If you've performed a bleed on a car a bicycle will be a breeze. You should try doing it yourself. I suspect some bike shops don't do a full bleed unless absolutely necessary, which ends up being a "go back to the shop a few times because I still need to pump the brake" type of exercise before it is done properly. Half the point of a brake bleed is to replace old crusty fluid with fresh fluid. The other half of the point is to make sure there's no air in the system. If a bike shop doesn't know this they should have their spanners confiscated. ChrisF, Eldron, Vishal72 and 2 others 5
MudLark Posted April 30, 2021 Author Posted April 30, 2021 If you've performed a bleed on a car a bicycle will be a breeze. You should try doing it yourself. I suspect some bike shops don't do a full bleed unless absolutely necessary, which ends up being a "go back to the shop a few times because I still need to pump the brake" type of exercise before it is done properly. Okay, maybe I get the kit some time and do it. Having the right bits and bobs always make life a bit easier.
MudLark Posted April 30, 2021 Author Posted April 30, 2021 (edited) Half the point of a brake bleed is to replace old crusty fluid with fresh fluid. The other half of the point is to make sure there's no air in the system. If a bike shop doesn't know this they should have their spanners confiscated. So, in defence of the bike shop: after I had got the bike back from the paint shop, I was on a ride. I noticed the brakes were spongy and I stopped off and asked the bike shop to take a quick look at it – The bloke said "Okay, just sit there for a moment and we will take a quick look at it". Came back after a few minutes said "Okay, we found a bit of air in the system; it seems to be better". Two days later the thing went "Oops, not so great any more". So then I took it back to the bike shop who said "Okay, let's look at it properly then. Leave it with us for a day or two". The bike shop is certainly not to blame here. Edited April 30, 2021 by MudLark
The Ouzo Posted April 30, 2021 Posted April 30, 2021 Okay, maybe I get the kit some time and do it. Having the right bits and bobs always make life a bit easier. Marvel generic brake bleed kit currently at cyclelab for 399, add another 200 for a small bottle of shimano unicorn tears , a few youtube videos and you are sorted. MudLark and Pusher 2
MudLark Posted April 30, 2021 Author Posted April 30, 2021 Thanks guys. So I spoke to the techie this afternoon when collecting the bike. He explained to me that the fluid they had to flush was definitely not Shimano fluid. He said it was much redder than Shimano fluid and much, much thicker. The other thing is that he showed me the top junction on the lever itself – it is a fairly long threaded barrel nut of sorts. He says that they use a type of Loctite which is grey in colour on that barrel nut. He found that some of this Loctite had got into the braking system – inside the lever junction and at a point where the hole the fluid passes through is actually pretty small. He thinks that it may also have been interfering with matters. Anyway, whatever the story, it's clear that the issue is now solved. Eldron and ChrisF 2
The Ouzo Posted May 1, 2021 Posted May 1, 2021 "Shimano Unicorn tears " LOLit may as well be given the price
MudLark Posted May 1, 2021 Author Posted May 1, 2021 it may as well be given the price CWC, R149 for 200ml. Not too bad really.
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