Yellow gunk in brake reservoir?

[Asher]

My friends master cylinder has stopped working and his reservoir has got this yellow gunk in it after a fluid change.
He was using Dot 4 fluid and replaced it with Dot 5.1 and he thought this might have cause a reaction but everything i have read says Dot 3-4-5.1 are all compatible with Dot 5 the odd one out.

Has anyone seen anything like this before and what do you think caused it?


316289

316290

[FJRider]

They are different formula's.

Your friend should drain and clean the lines before replacing with the (new/different) brake fluid.

[Asher]

Thats what im thinking too, although one would think that the entire point of the Dot standards is to avoid this sort of thing.

[FJRider]

Thats what im thinking too, although one would think that the entire point of the Dot standards is to avoid this sort of thing.

Dot 4 ... Dot 5.1. ..... a bit of a clue they are each a different standard ... ;)

[AllanB]

No issue going from 3 to 4 to 5.1 as they are all glycol based - the difference is their boiling point, higher as the numbers rise. I would add a full change of fluids should be done - not a top-up. I went from 4 to 5.1 with no issues at all.

Dot 5 is silicone based and must not be mixed with 3, 4 or 5.1.

Has he 5 in there? I suspect he has grabbed 5 not 5.1.

[Asher]

No issue going from 3 to 4 to 5.1 as they are all glycol based - the difference is their boiling point, higher as the numbers rise. I would add a full change of fluids should be done - not a top-up. I went from 4 to 5.1 with no issues at all.

Dot 5 is silicone based and must not be mixed with 3, 4 or 5.1.

Has he 5 in there? I suspect he has grabbed 5 not 5.1.

Yeah thats the same info as i have found but he is certain that he used Dot 4-5.1
I cant find any examples of anyone mixing Dot 5 with 3-4-5.1 so im not sure what that will look like.

[jellywrestler]

No issue going from 3 to 4 to 5.1 as they are all glycol based - the difference is their boiling point, higher as the numbers rise. I would add a full change of fluids should be done - not a top-up. I went from 4 to 5.1 with no issues at all.

Dot 5 is silicone based and must not be mixed with 3, 4 or 5.1.

Has he 5 in there? I suspect he has grabbed 5 not 5.1.

fuck, with all those numbers you'd be pretty well good at housie?

[AllanB]

fuck, with all those numbers you'd be pretty well good at housie?

Legs 11

88 two fat ladies

[boman]

Yeah thats the same info as i have found but he is certain that he used Dot 4-5.1
I cant find any examples of anyone mixing Dot 5 with 3-4-5.1 so im not sure what that will look like.

Look at your pictures. That's what it looks like to my memory.

I had to help someone clean out all their lines after they mixed DOT 4 & 5 together.

The mess resembled your pictures.

[AllanB]

Look at your pictures. That's what it looks like to my memory.

I had to help someone clean out all their lines after they mixed DOT 4 & 5 together.

The mess resembled your pictures.

Agree - if he still has the bottle I'd wage it is 5.0 NOT 5.1 ......

Nice avatar .... :niceone:

[AllanB]

All the manuals for the bikes I have owned have been pretty specifc about what number brake fluid to put in and nothing else. If you crash with a different brake fluid in you may not have insurance cover.

Yeah because your insurance company take brake fluid samples, boil them so they know the boiling point then assess if they are dot 4 or 5.1 .......

And then they check your oil to see if you had dino, semi-synthetic or full synthetic and check the oil weight against factory settings and determine if you deviated.

Then they inspect the tyre pressures and see if the match the factory recommendations.

And fuck me if you repainted anything you are totally stuffed.

[Kickaha]

If you crash with a different brake fluid in you may not have insurance cover.

You certainly haven't got any more intelligent

[Shaun Harris]

Yeah because your insurance company take brake fluid samples, boil them so they know the boiling point then assess if they are dot 4 or 5.1 .......

And then they check your oil to see if you had dino, semi-synthetic or full synthetic and check the oil weight against factory settings and determine if you deviated.

Then they inspect the tyre pressures and see if the match the factory recommendations.

And fuck me if you repainted anything you are totally stuffed.



Technically he is CORRECT ( Extreme yes, but correct) re the brake fluid. If an inspection of the fluid was done by the accessor, and he showed it had the wrong fluid in it, an insurance company could walk from the claim, as the bike was technically unsafe to be on the road, wof or no wof

[Big Dog]

Technically he is CORRECT ( Extreme yes, but correct) re the brake fluid. If an inspection of the fluid was done by the accessor, and he showed it had the wrong fluid in it, an insurance company could walk from the claim, as the bike was technically unsafe to be on the road, wof or no wof
Would that not only be so if you could be shown to have crashed due to brake failure and had fluid of a lower spec than specified?
My manuals have all stated a minimum rather than a specific spec.

Sent via tapatalk.

[schrodingers cat]

Nothing comes for free of course - the higher heat rated, silicon based fluids suffer from a little more compressibility and are more hydroscopic.

Unless you've ever actually boiled your brake fluid I cant see the point (esp for road use) to go any higher than DOT4.
In fact simply freshening the fluid every so often gives a better result than a 'better' fluid.
Want more feel? - get a different pad compound

If the brakes have had a real hiding - bleed them. A couple of pumps to get any old fluid out of the caliper and away you go again

[AllanB]

You have never heard of the serious crash unit have you? It would be them who would do any tests to see if the right fluid was used and the info would be passed to your insurance company in the same way as they will be notified if you crash without a warrant.

You watch too much TV. True if he had crashed and died they may have looked at that brake fluid.

None of this changes the fact that 3,4,5.1 are all compatible fluids when flushing out a system with new fluid.

DOT 5.0 IS NOT it is a silicone based fluid and WILL NOT MIX.

Maybe they should show this type of stuff on TV.


Adding to you insurance company rejection of a claim you will also find a clause stating illegal activity is not covered.

So never speed beyond the posted limit.
Shit don't go too slow either as you could get a ticket.
Never forget to indicate when turning.
Etc Etc Etc



Oh and a WOF is only a indicator of road worthyness at a given point in time. I have a new bike - it came with a three year WOF. Pretty sure my tyres won't last that long but it will still have a WOF. Your policy will speak to road worthyness or up to WOF standard.
Plenty of non roadworthy vehicles on the road with WOF's and no doubt many very road worthy ones with out them.

[AllanB]

Loath to get caught up in your posts but I am surprised you have not at least Googled your favorite brand of brake fluid to check. But your bikes manual will say you MUST take it to a authorized dealer to change the brake fluid so you probably have NO IDEA what DOT rating is in your own brake system ....

One thing I will note it was plain stupid labeling the non-compatible stuff as 'Dot 5'. Now that is dangerous given the previous labeling of 3, 4.

Here - I wasted some of my life for you:

http://www.elf.com/consumers/bike-oil/bikecare-product/elf-moto-brake-fluid-dot-5-1.html

http://www.mobil-carcare.com/products/brakefluid


Th OP needs to have his mate fess up at mixing Dot 5 in there, not the 5.1.

[Kickaha]

Maybe if you bought a workshop manual for your bike you may learn there is not the flexability with DOT ratings that you think for your bike.
Maybe if you knew what you were talking about you'd know there is

[nodrog]

Maybe if you knew what you were talking about you'd know there is

he's from the south island, he's trying his best.

[AllanB]

Maybe your Ducati manual says take it to a dealer but my Hondas have always stated a single DOT number and use nothing else. Honda actually stamp the DOT number on the cover of the fluid resovour too to try and ensure any fluid top up is correct. I am not interested in the opinions of non manufacterers recomendations for brake fluid so yes you have wasted your life looking up those websites. Maybe if you bought a workshop manual for your bike you may learn there is not the flexability with DOT ratings that you think for your bike.


Ah Grasshopper - up until two weeks ago I owned a HONDA from new for the past eight years. I even imported a full factory Honda manual for it (can't get them in NZ) Six of those years I ran DOT 5.1 in the brake systems (changed every two years) - and I added non-factory braided brake lines. Non-factory exhaust, bars, seat cover, levers, turn signals etc etc.

And that was South Island use too!

All brake reservoirs are labeled with a DOT rating - well at least for the past 34 years that I have been riding they have been. I hope you change your fluid at the Honda recommended intervals as otherwise your DOT rated factory approved fluid will be performing well below factory minimum specifications due to age and moisture absorption.

Interestingly you did not answer my question - who changes your fluid? And do you really know What they used?

Did you even read the links? In sue-me-for-farting-near-you US of A, how do you think those brake fluid makers can ever get away with such evil statements of rating capability?

So given all Ducatis come from the factory filled with Shell full synthetic and a sticker on the filler stating use Shell XX, do you think I should be worried that my Ducati dealer uses Motul or Castrol Oil? I'll be fine though as one of the first things I do with a bike is remove those pesky eye sores of 'must wear a helmet, adjust your chain, bla bla' stickers so the full glory of my bike is evident to all.

Did you frequent a Kawasaki USA web site about 10 years back? There was a guy on there who believed the old decent paint was factory paint - one should never use any other paint. He had even sold a bike once as the tank go a scratch in the paint and he could not have it repainted as Kawasaki did not build that bike anymore or stock a genuine factory painted tank.

[onearmedbandit]

For a thread on brake fluids this has provided me with much mirth.

[bogan]

For a thread on brake fluids this has provided me with much mirth.

I'm addicted to brake fluid...


...but I can stop anytime I want :bleh:




















what can't stop, is that joke being hilarious :innocent:

[Shaun Harris]

Would that not only be so if you could be shown to have crashed due to brake failure and had fluid of a lower spec than specified?
My manuals have all stated a minimum rather than a specific spec.

Sent via tapatalk.



NO mate. It proves alone that the vehicle was in an unsafe condition technically, so the Insurance company wins. But it would take a total ass hat and or cleaver adjuster to pick up on it. Most of them are just pen pushers really in reallity.


Min V a specific spec is stuck too, means the bike is technically safe as per manufacturers specifications.

[onearmedbandit]

NO mate. It proves alone that the vehicle was in an unsafe condition technically, so the Insurance company wins. But it would take a total ass hat and or cleaver adjuster to pick up on it. Most of them are just pen pushers really in reallity.


Min V a specific spec is stuck too, means the bike is technically safe as per manufacturers specifications.

As long as the performance of the brakes are not a contributing factor the insurance company can't walk away. During my years in the car industry I've seen insurance companies pay out even with a vehicle that either didn't actually have a WoF or had issues that had no bearing on the accident. Shit a good friend of mine was blinded by the sun, was involved in an accident that rolled his car and was paid out by the insurance company. The car hadn't even been vinned let alone have a warrant or rego.

[Shaun Harris]

Someone else as well as me who takes the instructions in manuals seriously. I bet if they bought out a DOT 10 brake fluid there would be some on this site rushing to buy it for their non Dot 10 brakes thinking they would be able to stop quicker.




yep, ignorance is bliss eh. Same re tire pressure also actually. The bike has a rec psi setting on it, but that is rellivant to the OEM tires it came out with. So throw on a diff set of hoops from a different company and different scientist that created them, and you need to RUN the new tires psi settings, not the old numbers on the chassis. ((5 Of most bikes shops do NOT even know that or consider it, they just follow the instructions from the original bike settings. Seriously bad and ignorent I say. Again, an Insurance could argue and win if they chose too, but doubt they would on that one, as I know for sure they would not have a clue about that either.

[Shaun Harris]

Nothing comes for free of course - the higher heat rated, silicon based fluids suffer from a little more compressibility and are more hydroscopic.

Unless you've ever actually boiled your brake fluid I cant see the point (esp for road use) to go any higher than DOT4.
In fact simply freshening the fluid every so often gives a better result than a 'better' fluid.
Want more feel? - get a different pad compound

If the brakes have had a real hiding - bleed them. A couple of pumps to get any old fluid out of the caliper and away you go again


I get your point re reg bleeding but, Another tech mistake re bleeding dude that many make, Air rises, so if any air is in the system, start at the master first, so you do not just push the air down from master to callipers. Or, purchase a very large Syringe, and reverse bleed, ie, fill syringe with app fluid, and attach hose to calipers and remove master cap, place good amount of rags to protect your bike, and flush fluid into the calipers and back out the master cyl. Hey presto, awesome leaver feel. Also tapping the callipers and brake lines whilst bleeding, helps release trapped air in the couplings, which are a major trapping point for air in brake systems.

[Shaun Harris]

As long as the performance of the brakes are not a contributing factor the insurance company can't walk away. During my years in the car industry I've seen insurance companies pay out even with a vehicle that either didn't actually have a WoF or had issues that had no bearing on the accident. Shit a good friend of mine was blinded by the sun, was involved in an accident that rolled his car and was paid out by the insurance company. The car hadn't even been vinned let alone have a warrant or rego.



No warrant or vin does not matter, as long as the vehicle is road worthyness, " FACT " ie up to a wof std condition. So YES they can dude, I also did a lot of insurance repair work here, and studied it very hard, in case I needed to fight for a customer,. As the repairer of such bikes, I worked for the customer, not the insurance companies. They the insurance companies just paid the bills. This is all tech man, so if the Insurance company wanted to fight you/us, tech they could, and would win, but they really do this, as time is money to them, and the negative PR would loose them future sales. I never had any dramas of 3 years with insurance companies and pay outs for jobs I quoted on. All the customers I did work for, were customers of Kiwibike insurance, a great broker for bike insurance, they also fight for there customers, not for the insurance companies as such.

[onearmedbandit]

No warrant or vin does not matter, as long as the vehicle is road worthyness, " FACT " ie up to a wof std condition. So YES they can dude, I also did a lot of insurance repair work here, and studied it very hard, in case I needed to fight for a customer,. As the repairer of such bikes, I worked for the customer, not the insurance companies. They the insurance companies just paid the bills. This is all tech man, so if the Insurance company wanted to fight you/us, tech they could, and would win, but they really do this, as time is money to them, and the negative PR would loose them future sales. I never had any dramas of 3 years with insurance companies and pay outs for jobs I quoted on. All the customers I did work for, were customers of Kiwibike insurance, a great broker for bike insurance, they also fight for there customers, not for the insurance companies as such.


Sorry my experience and discussions with the insurance ombudsman tells me otherwise. Do you seriously think an insurance company could refuse a claim if one of your headlights was out yet the accident happened during the day and headlights were'nt required. Technically that vehicle would be unsafe for the road as well.

[Shaun Harris]

Sorry my experience and discussions with the insurance ombudsman tells me otherwise. Do you seriously think an insurance company could refuse a claim if one of your headlights was out yet the accident happened during the day and headlights were'nt required. Technically that vehicle would be unsafe for the road as well.



as I did say dude, Technically they could, but also said, very much doubt it. I am the kinda person that likes to share all the facts, then it is up to whom ever to make there own decisions based on them. I will leave i at that now, no point in us debating about scemantics man.

[Big Dog]

Loath to get caught up in your posts but I am surprised you have not at least Googled your favorite brand of brake fluid to check. But your bikes manual will say you MUST take it to a authorized dealer to change the brake fluid so you probably have NO IDEA what DOT rating is in your own brake system ....

One thing I will note it was plain stupid labeling the non-compatible stuff as 'Dot 5'. Now that is dangerous given the previous labeling of 3, 4.

Here - I wasted some of my life for you:

http://www.elf.com/consumers/bike-oil/bikecare-product/elf-moto-brake-fluid-dot-5-1.html

http://www.mobil-carcare.com/products/brakefluid


Th OP needs to have his mate fess up at mixing Dot 5 in there, not the 5.1.

Other possibility, it already had 5 in it and his mate put 5.1 in?
Do any of us really know what the last mechanic put in the bike unless we bought it in the crate and installed the fluids ourselves?

[Katman]

....and are more hydroscopic.

As odd as it might sound, the word is actually hygroscopic.

[AllanB]

Other possibility, it already had 5 in it and his mate put 5.1 in?
Do any of us really know what the last mechanic put in the bike unless we bought it in the crate and installed the fluids ourselves?

Awwww man now you are really fucking with Casssssss's head! But a fair point.

[nodrog]

As odd as it might sound, the word is actually hygroscopic.

its grease lightening.....

[schrodingers cat]

As odd as it might sound, the word is actually hygroscopic.

Hmmm struggled there didn't I?
Mind you, I can spell pedant.