Replacing front brake reservoir?

Hi All,

So I've had my 650 for a bit over a month - loving it! - I had my MOT today (which is also the day that the current one expires) and I failed on a few minor items (my secondary horn fell off - the original only works at <50degrees and it was hotter than that during the test! missing exhaust baffle which my friend still has and my headlamp is "too far to the right" - possibly a task even I cant balls up!)

One of the items is the front brake reservoir that is attached to the bars.... I was checking the fluid level the other day and snapped the bottom that holds it into the bracket so I thought, I'll glue it with Araldite and jobs a good'un. Wrong! lol

I managed to get some brake fluid in the top of the diaphragm and cue a small leak!! (Which I subsequently remedied by taking it out and washing/drying the lid diaphragm and plastic gaskety thing.). So I bought a replacement which was delivered to the place where I was having my MOT done (ordered through them as they are nearby).

I've not found my question exactly - although thats not to say I didn't miss it!

Anyway - to my question. I asked one of the 'nics best way to replace it - he said it wasn't necessary to bleed the brakes as it was a remote reservoir.. which I thought made sense as the reservoir is above the master cylinder... but as I'm a TOTAL and UTTER NEWWWB.. I thought I'd ask your advice!

He was suggesting i tip most/all of the fluid out, shove a wadge of tissue/cloth in there , disconnect and reconnect the new one... I'm not terribly "handy" (infact my username is my nickname :P) and dont really want to have to bleed the brakes without knowing wtf I'm doing lol.

Any advice is much appreciated!

Firstly know that brake fluid works as an excellent paint stripper.
Secondly DO NOT operate the brake lever with the reservoir off (or without fluid level above the outlet from the reservoir)
Thirdly keep some tissues or rags to hand I case of spillage. Wipe any spilled fluid off and then give it a rinse with plenty of water.

1) empty the broken reservoir
2) fit the new one
3) fill with dot 4 brake fluid
4) give it a little tap or shake (with the lid on) to expel any bubbles.

Done and done.

Or ask them to do it for you for the price of a drink or a few quid in their teabag fund.

[muzikill]

The mot guys will sort it in a few secs with a few shot glass amounts of dot 4 which they will have by the bucketload in the garage. All they have to do is re-top it up once the switchover is complete and if done right the only place where there may be air is the small L shaped pipe that goes from the reservoir to the brake lever. All you have to do is top up the new part and raise it above the L shaped hose to allow the trapped air to 'float' up into the bottle. Strange that they would fail it if the break is solidly glued, unless the glued repair sticks out like a sore thumb.

Thanks for your help guys

I followed your advice and swapped it out myself.. I made sure i raised the reservoir above the pipe and tapped/lightly shook it (multiple times infact), i'm gonna do it again in the morning just to be doubly sure.

The glue was fine at first, but I had gotten some fluid in the diaphragm and it was leaking a little, so the glue didnt actually harden properly. and I broke it twice more when trying to remedy the situation!! (d*ckhead!)

in the end the repair was obvious and was infact hanging off (hence me ordering the new one). I had no problem with it failing, at least there was nothing major!

gotta find somewhere to remount my horn now lol... i found a piece of steel but the hole was just a little too small for the fairing bolt to go through without damaging the thread.. will drill it out when i get to work tomorrow and then take it back to the garage for a retest.

Why not replace the original with the second horn?

[muzikill]

Dont shake it you could be splitting a air bubble into tiny bubbles into the fluid mix. brake fluid bottles specifically tell you not to shake the bottle. What you want to do after filling it up is prop up the master cylinder at the highest point and make sure the pipe coming out is as vertical as you can get. Some people loosen off the brake lever and tip it down towards the middle of the bike so the area where banjo screws doesnt trap any air in. Then take out the diaphram and sit the lid on (dont tighten it) this will make sure the cylinder is not pressurised and stop dust/dirt/moisture getting in. Think about it, you want from the top banjo to the hole at the bottom of the master cylinder to be as vertical as it can to allow the air to rise up into the master cylinder. The air wont rise up if the cylinders closed off. If you leave it overnight that should give it enough time to work. Give the whole thing a few taps up the way with the end of a screwdriver up towards the cylinder the next day to make sure and leave it for 5 mins to allow any further air to rise to the top and retighten it all up. Check the reservoir level and that should be it.

Why not replace the original with the second horn?

Too big to fit in place of the original.. gonna hide it in the fairing on the left.

Dont shake it you could be splitting a air bubble into tiny bubbles into the fluid mix. brake fluid bottles specifically tell you not to shake the bottle. What you want to do after filling it up is prop up the master cylinder at the highest point and make sure the pipe coming out is as vertical as you can get. Some people loosen off the brake lever and tip it down towards the middle of the bike so the area where banjo screws doesnt trap any air in. Then take out the diaphram and sit the lid on (dont tighten it) this will make sure the cylinder is not pressurised and stop dust/dirt/moisture getting in. Think about it, you want from the top banjo to the hole at the bottom of the master cylinder to be as vertical as it can to allow the air to rise up into the master cylinder. The air wont rise up if the cylinders closed off. If you leave it overnight that should give it enough time to work. Give the whole thing a few taps up the way with the end of a screwdriver up towards the cylinder the next day to make sure and leave it for 5 mins to allow any further air to rise to the top and retighten it all up. Check the reservoir level and that should be it.

mate, i got 3 sentences in and got lost. I think (assuming i am not misunderstanding) i did what you suggest, make sure the pipe was verticle before inserting the new reservoir in the hose.

i hope the light shake hasnt made any air bubbles split. Wehn i connected the reservoir there was a bit of a hiss (I made sure that the pipe was nearly upright when i connected it, put fluid in, diaphragm in, tightened the lid, turned it upright again and tapped on both the pipe and the reservoir a few times and a light shake (the non vigourous variety - side to side motion). i tapped a few more times after letting it sit for a minute or so, opened the lid and lifted the diaphragm a bit and then put it all back. Was gonna undo the bolt again in the morning and turn it upright again and tap just to be sure... but it sounds like i'm now going to need to bleed the system?

You've done your best to stop air getting in and I'm sure it's absoulutely fine.

Now ride your bike!

[muzikill]

Originally Posted by monkey

You've done your best to stop air getting in and I'm sure it's absoulutely fine.

Now ride your bike!

Your probably right, but after just bleeding my own I know how small a difference there is between spot on and spongy.