Hydraulic brakes mineral oil

[ChrisF]

Instead of creating a new thread, did a search and didn't really find what I was looking for.

 

I need to bleed my shimano M505 brakes. I bought "shimano hydraulic mineral oil" from my LBS. It's red/pink in colour. I opened the reservoir in my brakes and the fluid is clear. The reservoir cover says mineral oil. I have never touched the brakes since buying the bike new and its never been to a bike shop either, so this is the original fluid.

Can I mix the fluid or must I drain the clear fluid and fill up with the new pink fluid?

 

 

Watch from 1:50

 

Post 111:

 

https://community.bikehub.co.za/topic/181779-mongoose-rebuild-project/page-7

 

 

 

Remove the cap at the top, remove the bleed nipple ... AFTER removing the brake pads !  Let the old oil drain out.  Pump new brake fluid into the system as shown.  Cheap enough that you could even let the new oil drain out again to flush the system.  Make sure there is enough oil in the reservoir that a drop or 2 spills over when you put the cap back on.

 

 

these older systems are much easier to bleed than the new systems - which must be bled from the top down ...

[DieselnDust]

Instead of creating a new thread, did a search and didn't really find what I was looking for.

 

I need to bleed my shimano M505 brakes. I bought "shimano hydraulic mineral oil" from my LBS. It's red/pink in colour. I opened the reservoir in my brakes and the fluid is clear. The reservoir cover says mineral oil. I have never touched the brakes since buying the bike new and its never been to a bike shop either, so this is the original fluid.

Can I mix the fluid or must I drain the clear fluid and fill up with the new pink fluid?

 

 

 

the dye is added in very low levels, like parts per billion. So in small volumes its hard to see the colour.

 

As long as the brakes are not feeling spongy you can just top up and rebleed. Full fluid replacement is also ok, Depends on your penchant for creating additional work for yourself. If you do rebleed be sure to bleed from both ends. water will collect at the caliper and master cylinder but mostly at the caliper so this end is most important to drain

[Long Wheel Base]

the dye is added in very low levels, like parts per billion. So in small volumes its hard to see the colour.

 

As long as the brakes are not feeling spongy you can just top up and rebleed. Full fluid replacement is also ok, Depends on your penchant for creating additional work for yourself. If you do rebleed be sure to bleed from both ends. water will collect at the caliper and master cylinder but mostly at the caliper so this end is most important to drain

Grab a full handful of brake and I don't need any extra watts to maintain the speed.............. It's just the rear, front is in tip top OTB shape.

The bike is about 7 years old, It parked on my wall for a while(front wheel up, so in like a wheelie position) and only gave problems when I started riding it again. No signs of leakage and pads still have good life in them. I have never serviced the brakes since new. I don't mind replacing all the fluid, I bought a small 50ml bottle so might as well use it. It does look like a schlep of a job but commuting with only 1 brake is risky.

[ChrisF]

Grab a full handful of brake and I don't need any extra watts to maintain the speed.............. It's just the rear, front is in tip top OTB shape.

The bike is about 7 years old, It parked on my wall for a while(front wheel up, so in like a wheelie position) and only gave problems when I started riding it again. No signs of leakage and pads still have good life in them. I have never serviced the brakes since new. I don't mind replacing all the fluid, I bought a small 50ml bottle so might as well use it. It does look like a schlep of a job but commuting with only 1 brake is risky.

 

I had similar cocncerns before doing Maritz's bike.  Turns out it is actually a very easy job.

 

KNOW that a few drops of oil will drop on the floor !

 

Have some paper towel ready to wipe off any oil from the bike, and old rags on the floor.

 

 

You DONT want any of this oil on the brake pads, nor on the brake disc !!!  Which brings me to another point - you say that you grab a handful of brake and the bike does not slow down ... that said, does the level move all the way to the grips, OR do you actually feel there is pressure in the system ??  All too often cleaning solvents or chain lube gets onto the rear brakes .... pressure in the system is fine, but you have ZERO stopping power !!

[Long Wheel Base]

I had similar cocncerns before doing Maritz's bike.  Turns out it is actually a very easy job.

 

KNOW that a few drops of oil will drop on the floor !

 

Have some paper towel ready to wipe off any oil from the bike, and old rags on the floor.

 

 

You DONT want any of this oil on the brake pads, nor on the brake disc !!!  Which brings me to another point - you say that you grab a handful of brake and the bike does not slow down ... that said, does the level move all the way to the grips, OR do you actually feel there is pressure in the system ??  All too often cleaning solvents or chain lube gets onto the rear brakes .... pressure in the system is fine, but you have ZERO stopping power !!

I will probably do the job here at work so cleaning up is sorted.

There is pressure in the system, the pads do move, just not far enough. I put some pads in with more life and they just touched. The lever moves all the way to the grip.

I will remove the whole brake from the bike completely and do the job far from my bike.

Thanks for the info.

[fanievb]

I will probably do the job here at work so cleaning up is sorted.

There is pressure in the system, the pads do move, just not far enough. I put some pads in with more life and they just touched. The lever moves all the way to the grip.

I will remove the whole brake from the bike completely and do the job far from my bike.

Thanks for the info.

 

try a "burp" bleed before you d full.

 

sounds like there is a bubble stuck which floated up during the storage

[Long Wheel Base]

try a "burp" bleed before you d full.

 

sounds like there is a bubble stuck which floated up during the storage

Burp bleed?

[fanievb]

Burp bleed?

 

basically brakes on bike (pads in etc.)

 

1. open the reservoir 
2. pump brakes and watch bubbles come up (while tapping the brakelines, caliper and reservoir, working from top to bottom)
3. keep on topping up the reservoir. (some spillage will occur)
4. once no more are bubbles top up oil to required level, close up and clean up.

no more spongy brakes (hopefully)

 

 

 

 

 

 

IIRC you can't youtube at work but here is the vid in any event.

 

https://www.youtube.com/watch?v=zckHR3-MMnY

 

 

[LOCO4360]

Burp bleed?

Where you level out the lever and make sure it is higher than the caliper (the more vertical you can get the bike the better -for rear brake). Open the bleed port on the lever, screw in the cup and fill it around a third with mineral fluid and then kind of pump the lever a bit and then flick the lever. Tap the brake hose from the caliper up to release air bubbles and this will generally assist with getting rid of spongy feeling. You may need to take the pads our and advance the pistons slightly. 

[fanievb]

Where you level out the lever and make sure it is higher than the caliper (the more vertical you can get the bike the better -for rear brake). Open the bleed port on the lever, screw in the cup and fill it around a third with mineral fluid and then kind of pump the lever a bit and then flick the lever. Tap the brake hose from the caliper up to release air bubbles and this will generally assist with getting rid of spongy feeling. You may need to take the pads our and advance the pistons slightly. 

 

m505 doesn't use the cup

 

[Long Wheel Base]

Where you level out the lever and make sure it is higher than the caliper (the more vertical you can get the bike the better -for rear brake). Open the bleed port on the lever, screw in the cup and fill it around a third with mineral fluid and then kind of pump the lever a bit and then flick the lever. Tap the brake hose from the caliper up to release air bubbles and this will generally assist with getting rid of spongy feeling. You may need to take the pads our and advance the pistons slightly. 

As Fanie said, mine doesn't have the little bleed port. My other bike does and that is much easier. Thanks I will try this burp method. 

[Long Wheel Base]

basically brakes on bike (pads in etc.)

 

1. open the reservoir 
2. pump brakes and watch bubbles come up (while tapping the brakelines, caliper and reservoir, working from top to bottom)
3. keep on topping up the reservoir. (some spillage will occur)
4. once no more are bubbles top up oil to required level, close up and clean up.

no more spongy brakes (hopefully)

 

 

 

 

 

 

IIRC you can't youtube at work but here is the vid in any event.

 

https://www.youtube.com/watch?v=zckHR3-MMnY

 

 

Thanks Fanie. Yeah no Youtube on work pc but I can check it on my phone. I have everything here at work so I will get to it just now.

[PhilipV]

basically brakes on bike (pads in etc.)

 

• open the reservoir
• pump brakes and watch bubbles come up (while tapping the brakelines, caliper and reservoir, working from top to bottom)
• keep on topping up the reservoir. (some spillage will occur)
• once no more are bubbles top up oil to required level, close up and clean up.

no more spongy brakes (hopefully)

 

 

 

 

 

 

IIRC you can't youtube at work but here is the vid in any event.

 

https://www.youtube.com/watch?v=zckHR3-MMnY

 

I've done that in the middle of an enduro race topping up with chain lube.

[PhilipV]

As Fanie said, mine doesn't have the little bleed port. My other bike does and that is much easier. Thanks I will try this burp method.

You'll probably find that there is very little fluid in the top reservoir. Maak hom vol.

 

I reckon take a Q-tip and put some oil around the pistons as well (sand pads please, and wipe off before replacing pads.) This makes it easier to centre pistons if they retract easily.

[DieselnDust]

You'll probably find that there is very little fluid in the top reservoir. Maak hom vol.

 

I reckon take a Q-tip and put some oil around the pistons as well (sand pads please, and wipe off before replacing pads.) This makes it easier to centre pistons if they retract easily.

 

 

 

NOOOOOOOOO! don't maak hom vol. It needs a bit of headspace to allow for fluid expansion. If you maak hom vol then brakes will start applying themselves

[ChrisF]

NOOOOOOOOO! don't maak hom vol. It needs a bit of headspace to allow for fluid expansion. If you maak hom vol then brakes will start applying themselves

 

Over filling is obviously a big no-no !!

 

 

What I did was to slightly over fill it -

 

 

I then placed the rubber bladder, gently pushing it down with my fingers, while the excess oil over flowed (great time to have that paper towel close by) -

 

 

 

With the system full, but not over-filled, I replaced the cap.