Shimano Hydraulic brake question...

Guys/girls, need a bit of help here!

My knowledge on hydraulic brakes is a little limited. However, last weekend I attempted to bleed my brakes as the rear one had gone very spongey. Managed this fine (shimano br m485) and the rear brake now stops again.

However, when I came to do the front I realised that when I had an off last year I completely smoothed the head out on the cross head, so only way to remove was to drill out & replace. Having searched on eBay for a replacement screw I failed and started looking for a cheap brake instead.

I came across a set of shimano br m486 which look identical just slightly different branding/logos. These were supplied ready bled but they have very short hoses and are connected to the wrong lever for UK use (my preference) but this is probably why they cost less than £15 each!

Anyway, I bought them with the intention of using the levers on my brakes, possibly the calipers too. Question is, what do I actually need to do? Is it a question of just undoing and replacing then re bleeding or do I need to change olives etc too?

Your help would be much appreciated!

AJ

the shimano will have metric screws - I am guessing here but you probably need to find an M2.5 cross head screw (or M2 or M3) - cannot be that hard to find, in fact I bet you I will have one in my box of screw - it won't have the washer but that is easily rectified.

secondly your second set of brakes - just undo the hollow bolt at the lever end and swap over the hoses or use the old hoses. only if the fitting at the lever is different - can either be banjo or hollow bot - will you need to do something difffernt.

I believe the fittings at the lever are identical.

So what I want to do is undo the hoses at the lever, then remove my old levers from the bike.
Put the new identical levers back on to the bike, and reconnect the hose. But im uncertain if I need to put new olives onto the old hose to do this?....

Current lever



New lever

If all is the same you should be able to get away with re using the olives.

i do believe these are the cheap CRC ones. i got them and have the same problem. will be swapping the levers over. i think from brand new (as far as i have been told) swapping over should be fine - including keeping the olives - but to be honest i'll probably replace mine as they are 'press fit'/crushed when tightened. no need to replace anything else i imagine although i need a longer hose for the rear so not as straight forward for me

Yeah they are from CRC mate, however the olive will be already on the hose from the old brakes, so they are a few years old.

They do crush a tiny little bit when fitted (these generally dont need a huge amount of tightening). Often it is ok, you can either try and see if they work or just use new ones regardless. Age shouldnt be a bearing in this i wouldnt have thought unless they are ehavily corroded ro something.

I have mentioned at the same time people should have gotten the goodridge kits which were on sale at the same time.

cyfa2809":21pr8fyu said:

If all is the same you should be able to get away with re using the olives.

Click to expand...

Not that anyone would recommend such recklessness with one of the few weak links in the hydraulic systems we have.
I advise not to use the same olive,not like they're expensive and it effectively could mean your life so get it right first time.

dyna-ti":1ybz29b1 said:

cyfa2809":1ybz29b1 said:

If all is the same you should be able to get away with re using the olives.

Click to expand...

Not that anyone would recommend such recklessness with one of the few weak links in the hydraulic systems we have.
I advise not to use the same olive,not like they're expensive and it effectively could mean your life so get it right first time.

Click to expand...

It's hardly "recklessness" to suggest that you could swap hoses over between identical master cylinders without cutting off the end of the hose with the old olive on and using a new one. The olive is already "set" onto the hose so it doesn't care whether it's fitted to the new or old master cylinder. There might be microscopic surface finish differences between the two cylinders but it won't be an issue any more than the fact that two machined surfaces will never be a perfect match before one has deformed to fit the other.
I don't see any problem with doing this - I've swapped brake levers from left to right several times and I don't recall ever replacing the compression olives when doing so. I wouldn't consider compression olives a weak link in any hydraulic system, let alone bicycle brakes.