Hydraulic brakes mineral oil

[PhilipV]

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

When you insert the bladder, it squeezes out enough fluid. The expansion space is between the rubber bladder and the cap.

[PhilipV]

Over filling is obviously a big no-no !!

 

 

What I did was to slightly over fill it -

 

Mongoose revamp-221.jpg

 

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) -

 

Mongoose revamp-222.jpg

 

 

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

Netso.

If the bladder is in and seated, then it's nigh impossible (nothing is) to overfill the system.

Just slightly messy to clean up afterwards.

LWB fixes planes, he should understand this system when he is done.

 

My guess is that there isn't enough fluid in his system, so when he pulls the lever it is pushed into the top reservoir instead of applying pressure at the slave piston. If there is enough fluid, then he'll have sufficient pressure at the slave to apply force on the disc.

Edited June 26, 2019 by PhilipV

[Long Wheel Base]

Netso.

If the bladder is in and seated, then it's nigh impossible (nothing is) to overfill the system.

Just slightly messy to clean up afterwards.

LWB fixes planes, he should understand this system when he is done.

 

My guess is that there isn't enough fluid in his system, so when he pulls the lever it is pushed into the top reservoir instead of applying pressure at the slave piston. If there is enough fluid, then he'll have sufficient pressure at the slave to apply force on the disc.

Spot on. The reservoir is, for lack of a better description, just wet inside.

[DieselnDust]

Over filling is obviously a big no-no !!

 

 

What I did was to slightly over fill it -

 

Mongoose revamp-221.jpg

 

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) -

 

Mongoose revamp-222.jpg

 

 

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

 

 

 

YA I get that okes are doing this. Remember that the rubber gland is flexible and the fluid has pressure because it has nowhere to go. You will threrefore still have too much fluid volume .

 

I get around this byjust filling to the max fill line in the reservior and then gently replacing the rubber gland by pinching the two long ends together and then easing the gland in place from the centre to the outside. this pushes any air outward and there's enough expansion space.

[Jewbacca]

Yass you guys make a meal out of a relatively simple process! 

[Long Wheel Base]

Done. Wow brake feels good. Can't wait for my ride home. Probably going to lock up a few times initially. Flip it feels so good I think I am sommer going to do the front quickly.

[DieselnDust]

Yass you guys make a meal out of a relatively simple process! 

  cos we smaak the techiestuff man

 

 

 

Done. Wow brake feels good. Can't wait for my ride home. Probably going to lock up a few times initially. Flip it feels so good I think I am sommer going to do the front quickly.

 

 

I love mineral oil systems. So easy to work on

[Long Wheel Base]

[Long Wheel Base]

  cos we smaak the techiestuff man

 

 

 

 

 

I love mineral oil systems. So easy to work on

When I was still an appy, the aircraft I worked on used a very similar oil in the hydraulic system. It was nicknamed "red oil". Now the stuff we use on the big kites is terrible. It's called skydrol, it's flipping hazardous, chows paint. If you get that stuff on your skin it burns.

[DieselnDust]

When I was still an appy, the aircraft I worked on used a very similar oil in the hydraulic system. It was nicknamed "red oil". Now the stuff we use on the big kites is terrible. It's called skydrol, it's flipping hazardous, chows paint. If you get that stuff on your skin it burns.

 

 

Are you refering to Aeroshell 41?

[Long Wheel Base]

Are you refering to Aeroshell 41?

Depending on the brand it had different names. MIL-H-5606 is the spec. But yes, that is what shell calls their "red oil".

[madmarc]

I have bled many bike brake systems, mainly SRAM & Magura - what i have found is, there are so many nooks and kranies in the system where small amounts of air bubbles lodge, its difficult to get them out, when you think you have it sorted, a few days later the air bubbles dislodge from where they hiding and your brakes are spongy again so you need to re-bleed.

 

I normally bleed like normal then I remove the caliper and shake it around and tap with a screwdriver handle while pulling a vacuum on the syringe, do the same with the brake lever.

 

I tried a crazy thing the last time - I took my orbital sander (without the sandpaper of course) and held it against the caliper for a few seconds making sure the bleed port was at the highest point, at the same time pulling a vacuum and was surprised at the amount of air bubbles that were released - Seemed to work.

 

I have also found that if your brakes seem to lose pressure while standing for no reason then time for new seals in the lever and perhaps even new piston seal kits as well

[DieselnDust]

I have bled many bike brake systems, mainly SRAM & Magura - what i have found is, there are so many nooks and kranies in the system where small amounts of air bubbles lodge, its difficult to get them out, when you think you have it sorted, a few days later the air bubbles dislodge from where they hiding and your brakes are spongy again so you need to re-bleed.

 

I normally bleed like normal then I remove the caliper and shake it around and tap with a screwdriver handle while pulling a vacuum on the syringe, do the same with the brake lever.

 

I tried a crazy thing the last time - I took my orbital sander (without the sandpaper of course) and held it against the caliper for a few seconds making sure the bleed port was at the highest point, at the same time pulling a vacuum and was surprised at the amount of air bubbles that were released - Seemed to work.

 

I have also found that if your brakes seem to lose pressure while standing for no reason then time for new seals in the lever and perhaps even new piston seal kits as well

 

 

 

the SRAM bleed kit is the best one. the two syringes allow you to push and pull the fluid through the system to get the air out.

A trick i've used successfully is to turn a hairdryer onto the caliper to heat it up. this lowers the viscosity in the fluid and it sheds the air bubbles more quickly.

[ChrisF]

Capture.PNG

 

 

YUMMIE ..... that is one nice "tool box" ...    

[SwissVan]

Capture.PNG

Have you got a Form 8130/ One for those parts??

[madmarc]

Another problem is the pistons get stuck, so only one piston is actually cycling when pulling brakes. I remove the wheel and brake shoes - I pull the brakes while holding the moving piston back with a tyre lever, until the stuck piston moves, then i stroke both pistons out a bit and clean with earbud and benzene, lube with some brake fluid. they work like new afterwards