Topping up front brake fluid.

[rosie631]

Ok. :Playnice: Very basic question here. Have checked my front brake fluid and the little box thingy is about quarter full. Presuming I have to add some. But how full should it be? And do I have to bleed lines or anything or is if just a matter of topping it up? No chance of air lock or anything like that??
Oh, bike is 95 FXD harley.
Thanks in advance.

[nallac]

No bleeding needed if the level is a little to low.

When was the fluid last changed?,would be a good time to do it
if it hasn't been done in a while..

Also do you know if it is Dot 4 or Dot 5 fluid in there?.

[doc]

Make sure its SILICONE brake fluid, or you will be sorry.

[nallac]

Make sure its SILICONE brake fluid, or you will be sorry.

By that he means Dot5 Harley fluid...Even tho you can use Dot4
in its place,it's just more likely to eat your paint if any is spilt.

[Quasievil]

There should be a level indicator on the reservoir full it to the full mark line.
Also it should say on the lid of the reservoir what to put in it.
Also ask the dealer with the franchise for your bike, they can help you out.

lastly its important you check it and do it regularly good idea to get a owners handbook if you dont already.

[rosie631]

I have a manual but it's pretty crappy. Says Dot5 brake fluid. Lines due to be bled but a friend will be helping me with that in a month or so. Just wondering if I should top it up in the meantime. Quarter seems quite low. Don't want to suddenly have no brakes.

[98tls]

I have a manual but it's pretty crappy. Says Dot5 brake fluid. Lines due to be bled but a friend will be helping me with that in a month or so. Just wondering if I should top it up in the meantime. Quarter seems quite low. Don't want to suddenly have no brakes. Just buy a little bottle and top it up,its as cheap as chips.

[Quasievil]

I have a manual but it's pretty crappy. Says Dot5 brake fluid. Lines due to be bled but a friend will be helping me with that in a month or so. Just wondering if I should top it up in the meantime. Quarter seems quite low. Don't want to suddenly have no brakes.

mate best thing take to the dealer on Monday and ask them for a quick check on it.

[nallac]

Just buy a little bottle and top it up,its as cheap as chips.

Just make sure its the same fluid as is already in there.
Not good to mix Dot4 and 5.

If its Dot5, its not cheap compared to Dot4 to buy........

[doc]

Don't want to suddenly have no brakes.

Hey, we are talkin harley brakes, that why they sell Johnny Rebs, they assist with your braking force. :banana:

[CookMySock]

I have a manual but it's pretty crappy. Says Dot5 brake fluid. Lines due to be bled but a friend will be helping me with that in a month or so. Just wondering if I should top it up in the meantime. Quarter seems quite low. Don't want to suddenly have no brakes.You won't suddenly have no brakes because of low brake fluid. Something has to blow its' arse real bad for that to happen.

It is more likely low because of brake pad wear. If it makes you feel better, then top it up for sure. It's not going to cost you a lot. No point riding around worrying about crap when you can fix it with a flick of your little finger.

Steve

[AllanB]

This may sound a bit foolish, but are you checking it with the master cylinder level? I ask as many have the front cylinder on a angle (particularly cruisers) and you need to turn the bars to get it level before taking a reading.
With the bars straight forward and the master cylinder on a angle it may read a quarter but actually be full.

[rosie631]

Not sure. Just checked it with the bike on the stand. I will go ahead and top it up but just wanted to check if it's ok like it is. Going for a big ride today and haven't got time to get the brake fluid first. Will recheck with it level too.
Cheers everyone for the advice.

[Max Preload]

Once you've correctly verified the current level don't just top it up - check the brake pad friction material first. If the fluid is low you've either got a leak (unlikely) or the pads are worn. The reservoir size is designed to have sufficient fluid to still have spare capacity when the piston(s) have travelled to their limit when the pads are worn.

In any case, change the fluid whenever you change pads.

[Owl]

Shouldn't the fluid be completely replaced? Especially Dot 5, as water collects at the calliper/s and does not get absorbed by the fluid.:confused:

[rosie631]

Thanks for all the advice everyone. Won't be worrying about the brakes for a while. Took a spill yesterday and bike is pretty banged up. And no, it was nothing to do with the brakes LOL.

[sinfull]

Sorry to here about the spill, seems to be a bit of that going on again !

[Goblin]

:shit: Oh shit Rosie! Hope you are ok and not broken.

[rosie631]

Sorry to here about the spill, seems to be a bit of that going on again !

Yep, joys of winter riding eh?

[rosie631]

:shit: Oh shit Rosie! Hope you are ok and not broken.

Thanks Goblin. No, nothing broken. Was knocked out so got a bit of concussion. Otherwise the leathers etc did their job. Very thankful. It could have been so much worse.

[sinfull]

Yep, joys of winter riding eh?Well when ya do get it back on the road and replace them front pads, bleed the lines and leave the reservior full so ya know next time it gets low, your pads are down so it's time to do it all again !
Not the spill that is !!
It's usually a good gauge for pad wear, then when ya push the caliper pistons back it fills the resevoir up to the full level again (or it should)
On the track you'd be bleeding ya lines more regular due to overheating of the fluid, i've got myself into the habit of a half doz pump/bleeds before each track day, but then your replacing pads a lot more often too lol !
But i digress, though i'm on topic for a change lol
Where're the pics and what happened ???

[98tls]

Thanks for all the advice everyone. Won't be worrying about the brakes for a while. Took a spill yesterday and bike is pretty banged up. And no, it was nothing to do with the brakes LOL. Bugger,glad to hear your ok.Hope the bikes all fixed up for the summer.

[rosie631]

Where're the pics and what happened ???

No pics. Riding in the wet. Open road, on the straight. Hit a greasy patch of road and two of us went down. Bikes just flew out from under us. Long slide down the road but the gear did its job and we both walked away. Can't ask for more than that eh?

[steve_t]

Knocked out?! Glad to hear you're OK! Coming back through Te Awamutu to Hamiltron, the left lane of the two laned open road was rainbow coloured! I think someone must have been haemorrhaging a crap load of oil!! :angry: Take care on the wet/greasy roads everyone! Sorry for all the exclamation marks! :shutup::laugh:

[scumdog]

Not sure. Just checked it with the bike on the stand. I will go ahead and top it up but just wanted to check if it's ok like it is. Going for a big ride today and haven't got time to get the brake fluid first. Will recheck with it level too.
Cheers everyone for the advice.

NEVER spill any on your paint - silicone fluid is not as bad but the old stuff is as good as paint stripper.

Wash it off with water as soon as you can if you DO spill any.

And keep the lid on the master-cylinder except for when you are actually topping it up - brake fluid sucks moisture out of the air and is water Not Good(tm) on brake systems.

[mouldy]

Do not mix silicone and mineral based fluids and always leave an air gap in your master cylinder , brake fluid expands as it heats up and always check the level after putting in new pads .

[The Stranger]

Sorry to hear about he spill. But one other thing I don't see anyone else mention here yet. The fluid is "missing" because of pad wear. Any time you need to add fluid you should check to ensure you have sufficient brake pad thickness left.

[scumdog]

Sorry to hear about he spill. But one other thing I don't see anyone else mention here yet. The fluid is "missing" because of pad wear. Any time you need to add fluid you should check to ensure you have sufficient brake pad thickness left.

And don't forget that if you put new pads in and have to force the pistons back a bit (and you will) that the fluid has to go 'somewhere' - back up to your master-cylinder - so check there's enough space in the cylinder for it to go into.

[The Stranger]

And don't forget that if you put new pads in and have to force the pistons back a bit (and you will) that the fluid has to go 'somewhere' - back up to your master-cylinder - so check there's enough space in the cylinder for it to go into.

Hmm, sounds like someone remembers this lesson well.

[Max Preload]

NEVER spill any on your paint - silicone fluid is not as bad but the old stuff is as good as paint stripper.

Not just the 'old' stuff. DOT 5.1 is glycol based too just like DOT 4 & DOT 3.


And don't forget that if you put new pads in and have to force the pistons back a bit (and you will) that the fluid has to go 'somewhere' - back up to your master-cylinder - so check there's enough space in the cylinder for it to go into.

You should never force the fluid back up the line because the moisture and accumulated muck from the caliper goes with it and can causet he master cylinder to wear prematurely and the tiny hole to block which means the brakes won't fully release. The way to do it is put a hose on and crack the bleed nipple before pushing the pistons back - that expells the dirtiest fluid directly from the caliper and makes purging the rest with clean fluid from a previously unopened container (that last point about "unopened" not quite so necessary with DOT 5 but still good practice).


But one other thing I don't see anyone else mention here yet. The fluid is "missing" because of pad wear. Any time you need to add fluid you should check to ensure you have sufficient brake pad thickness left.


Once you've correctly verified the current level don't just top it up - check the brake pad friction material first. If the fluid is low you've either got a leak (unlikely) or the pads are worn. The reservoir size is designed to have sufficient fluid to still have spare capacity when the piston(s) have travelled to their limit when the pads are worn.