Flush brake fluid

[DriveHard]

Originally Posted by Dackelone

Back when I use to do a lot of track days and we (a friend of mine) raced in the SCCA's ITb class... we used Ford's H.D. brake fluid DOT4. Laugh if you want but the specs of that stuff was better than almost anything else around. AND it was dirt cheap. We also used AP's 550 brake fluid - but that stuff was more $$. But the problem with AP's (or any other racing) brake fluid is the wet boiling point is kind of low and it attracts moister faster than OE brake fluid. Corosion is not good with todays ABS and traction control systems. BLLED YOUR BRAKES!

So.... IF you run a racing brake fluid... change it often - atleast twice a year. More often if you do HPDE or races.


For US cars BMW says to change the brake fluid every two years. Over here, BMW AG says to change the brake fluid every year.

When a German takes his car to the German safety inspection place (TUV) they take a small sample of brake fluid out and put it in a little heating device that measures the point at which the fluid boils. Your car MUST pass this test. This is a good idea.


For the street I use a German DOT4 brake fluid from my indi parts place over here - Stahlgrube: Car Technic wet boiling point - 165'C and dry boiling pont of 265'C.







Does anyone know what the specs are for BMW's OE brake fluid? The stuff that the dealer sells? I bet its made by either ATE or Castrol.


Dackel

BMW High Performance Brake fluid Dot 4 P/N 81220142156
Conforms to FMVSS No: 116 and SAE J1703

Minimum Wet Boiling 311*f (155*c)
Minimum Dry Boiling 446*f (230*c)

Made in USA Dist. by BMW NA ... no other indications of manufacturer of fluid..

[Dackelone]

Originally Posted by DriveHard

BMW High Performance Brake fluid Dot 4 P/N 81220142156
Conforms to FMVSS No: 116 and SAE J1703

Minimum Wet Boiling 311*f (155*c)
Minimum Dry Boiling 446*f (230*c)

Made in USA Dist. by BMW NA ... no other indications of manufacturer of fluid..

Thanks DriveHard! Looks like my stuff has better specs. And its pretty cheap too over here (five euros for 1L bottle).


Dackel

[Lubo]

Originally Posted by Dackelone

Then follow Castrol's recomendations. I realy can not say one way or the other. I would still go with BMW AG's recomendation of yearly brake fluid changes though.

I do think IF you are going to track your car... you should be flushing the brake fluid and changing the engine oil before each event. I think that is just basic mantainence (& commen sense) for track cars. Besides... when you start to pull off wheels and do the brake fluid flush... you are liable to discover a small problem that could develop into something big. Afterall... it is YOUR life on the line.

You do not need to flush the SRF prior to each event. That is $70/.5liters you would be wasting. And you need 3 to 4 bottles to do a complete flush. If you did cook the fluid and got some air in the lines you need to adjust your driving style as there is nothing else with higher boiling temperature.

[DriveHard]

Originally Posted by Dackelone

Thanks DriveHard! Looks like my stuff has better specs. And its pretty cheap too over here (five eurps for 1L bottle).


Dackel

exactly how much is an "eurps" ???? LOL

and your welcome !! yeah your stuff looks good.. USA stuff retails for $7.48 for .35 Liters ( 12 oz)

I use ATE.. I like the pretty blue color

and i only do a quick bleed after every event...no flush till end of season

[Dackelone]

Originally Posted by Lubo

You do not need to flush the SRF prior to each event. That is $70/.5liters you would be wasting. And you need 3 to 4 bottles to do a complete flush. If you did cook the fluid and got some air in the lines you need to adjust your driving style as there is nothing else with higher boiling temperature.

You got me curious about this Castrol SRF (racing)brake fluid, so I googled the specs...

DOT4

dry boiling point: 320' C
wet boiling point: 270' C

50 euros for a 1L bottle.

http://www.oelwelt24.de/catalog/1+L....ng+Brake+Fluid


Still... it IS marketed as a racing product so that really means you must test it or replace it often. Not pour it in and forget like a street product. I think yearly brake fluid flushes make sense for street cars. As for race cars or street cars that see a lot of HPDE... if you can afford to pay... don't play. Replacing brake fluid, engine oil, trand and diff fluid, tires, brake pads and rotors... is just the price "we" pay to play out on the race track.

[Dackelone]

Originally Posted by DriveHard

exactly how much is an "eurps" ???? LOL

and your welcome !! yeah your stuff looks good.. USA stuff retails for $7.48 for .35 Liters ( 12 oz)

I use ATE.. I like the pretty blue color

and i only do a quick bleed after every event...no flush till end of season

ok, I fixed that typeo of mine! You made me chuckle! lol

Yea... well... even a quick bleed is better than nothing. Its just some people think since they have the GOOD STUFF in there... they can forget about it. That is all I was trying to say.

You know its like Mark Donohue and Roger Penske have written about... when your race car is clean... and detailed... it makes it easier to find/discover when something is broken or about to break/crack.

When you are doing HPDE and pushing yourself AND your car... you should take time to check all those little things that can lead to a big accident. Even something simple as bleeding your brakes.

Dackel

[pixelblue]

I think Dackel is referring to me above from an earlier post. guess I should clarify a few things before I am painted with a broad brush and categorized as a reckless speed crazed nut

as a part of my post track day inspections, I take apart the brakes after each event and thoroughly inspect everything for signs of wear and stress. I haven't bleed my brakes partly because I haven't noticed any sponginess or decrease in brake performance.

my service guys run the insight racing team in the continental tire series and last year before the track season I had them throughly inspect the car and told them to flush all the fluids including the radiator but they told me it's too early to worry about it and I should do it the following year. they told me that if oil temps don't go over 280 I wouldn't need to change the motul 300v oil and it should be good for 6-8 track days. obviously their knowledge and experience is invaluable to me.

so yes I wish I could afford to change everything after every track event but as you said, it gets expensive when you start adding everything up. meanwhile I have to take extra caution and keep a sharp ear and sense for how the car behaves and to make sure you don't drive the car recklessly but still have a ton of fun within the limits

[Dackelone]

Originally Posted by pixelblue

I think Dackel is referring to me above from an earlier post...

No, no. I wasn't talking about anyone in particular! (in past above posts). I was only talking in general terms of track maintenance needs.

[Xaeryan]

Originally Posted by pixelblue

I think Dackel is referring to me above from an earlier post. guess I should clarify a few things before I am painted with a broad brush and categorized as a reckless speed crazed nut

as a part of my post track day inspections, I take apart the brakes after each event and thoroughly inspect everything for signs of wear and stress. I haven't bleed my brakes partly because I haven't noticed any sponginess or decrease in brake performance.

my service guys run the insight racing team in the continental tire series and last year before the track season I had them throughly inspect the car and told them to flush all the fluids including the radiator but they told me it's too early to worry about it and I should do it the following year. they told me that if oil temps don't go over 280 I wouldn't need to change the motul 300v oil and it should be good for 6-8 track days. obviously their knowledge and experience is invaluable to me.

so yes I wish I could afford to change everything after every track event but as you said, it gets expensive when you start adding everything up. meanwhile I have to take extra caution and keep a sharp ear and sense for how the car behaves and to make sure you don't drive the car recklessly but still have a ton of fun within the limits

I started with fresh oil, then did a UOA after two track days. Results were waaay within spec. So I went four track days before the next UOA - results still very much in the clear. So next I will try one after 6 track days, which I am guessing will still be in the clear, but might give a comfortable buffer (peace of mind). It gets expensive to replace oil all the time, so I use data to determine when it is actually needed. I'll use the money saved to attend more track days, and a virtuous cycle ensues.

I'd like to do the same with the brake fluid, to at least give me a general guideline for how long before the dry boiling point is reduced to wet for the fluid I use, but haven't got around to figuring out how I can get it tested myself. So far, I started the season with a flush and had no issues 6 track days in. I just did a flush as a precautionary measure, but I doubt I was anywhere close to the current boiling point anyway.

As for the aforementioned pre/post track inspections, definitely mandatory. You'll wanna include checking the ceramic piston caps to make sure they haven't powderized.

[DriveHard]

We could all buy this !!!! ( im joking...ill just bleed them damn things LOL )

http://www.amazon.com/Brake-Fluid-Sa...=pd_sbs_auto_3

[pixelblue]

Originally Posted by Dackelone

No, no. I wasn't talking about anyone in particular! (in past above posts). I was only talking in general terms of track maintenance needs.

ok nevermind

[romak47]

do our cars require the wheel off to reach the bleeder valve on the front and rear brakes?

which fluid is clear and has a better / higher boil point than the OEM stuff?

Also, whats the process to bleed the brake pump cylinder when using the motiv bleeder?

[pixelblue]

Originally Posted by romak47

do our cars require the wheel off to reach the bleeder valve on the front and rear brakes?

which fluid is clear and has a better / higher boil point than the OEM stuff?

Also, whats the process to bleed the brake pump cylinder when using the motiv bleeder?

yeah you need to take the wheels off. I use motul RBF 600 which is considered one of the better ones. of course castrol SRF is considered the best but it costs $75 for a small bottle. as far as the bleeder, it's quite simple. you attach the pressure cap to the reservoir and you pump enough pressure into it and the rest is normal method to bleed. some people actually place the brake fluid directly inside the motiv container but I don't because cleaning that sh*t later is not fun.

[Dackelone]

Originally Posted by romak47

Also, whats the process to bleed the brake pump cylinder when using the motiv bleeder?

Also... when using any pressure bleeder do not pump it up more than say 10 psi. I once saw a mechanic pump it up to 15 psi and the prssure bleeder blew off the res from the master cylinder! What a mess! So this is the reason why you don't want to go over 10 psi.

Always start your bleeding from the longest brake line first: right rear, left rear, right front, left front. For UK drivers IF the master cylinder in on the "other side" (ie in front of the driver, then you have a different bleeding order). Just remember longest brake lines first!

Sometimes it doesn't hurt to use a small rubber hammer to tap the brake caliper as you have the bleed nipple/valve open. This will "move" any trapped air bubbles.

I always use a CLEAR (6mm ?) hose on the bleeder valves. This will show you when there are air bubbles in that caliper. I always like to bleed each corner a few times. Brake fluid is cheap.

AFTER you are done... depressurize the Motive bleeder. You do this by SLOWLY opening the T-handle pump (CC). Do it slowly so you don't spray any brake fluid all over your car! Then, once depressurize - you can remove the brake res adpator cap. The brake res will be over filled at this point. I use a clean Turkey baster to remove some brake fluid from the res. Make sure you are at the MAX mark on the res. There is an arrow on the side of the res.

Some other tips... spray some penatraiting oil on the bleed valves BEFORE you try tp open them. USE a 12 point wrench or better yet, buy some flare tool wrenches. This will grab and hold the bleed vales better and not be prone to stripping or rounding the valve. Nothing worse than breaking one while trying to bleed your brakes. Don't go nut retightening them either. ALWAYS have some "Brake Kleen" on hand, just incase you spill some brake fluid on a painted surface. I like to use the CRC products bc they are non flamable.


Dacxkel

[pixelblue]

^ spot on directions! Flare wrench is a must. I believe it's a 11mm?

[Dackelone]

Yes, 11mm. Just incase someone does not know what a flare wrench tool looks like... here is a pic...

[e82n54]

Well, I flushed my brake fluid for my first time... and the brakes stop the car with little to no fade so far.

I don't think it went as well as it should have though. For one thing it took hours, but the main problem was that the fluid never came out the color I expected. I was going to go with Motul RBF600, but I had already ordered Castrol SRF and it was too late to cancel it, so I just used it. I also decided against the ATE Super Blue as an indicator. The Castrol fluid looks completely clear. The fluid in my brake reservoir was brown and had junk floating in it! I just had my rear brake pads replaced at the dealer!

So here's what I did:
I wanted to make sure I didn't waste the Castrol fluid, so I suctioned out most of the fluid in the reservoir with a surgical irrigation syringe. I stopped when the old fluid was up to about the "Min" (minimum) mark. I put all the suctioned fluid in a plastic water bottle and marked a line at the fluid level to record this volume of fluid. I dumped out the plastic bottle into a glass jar for disposal somewhere (don't know where). I then poured in the Castrol fluid up to the "Max" arrow and hooked up and pressurized the empty motive pressure bleeder. I started with the passenger rear. At first the fluid came out dirty brown, then changed to a pale yellow, but it didn't come out clear. At this point I had reached the mark on the plastic bottle, so I decided to move on and avoid running out of new fluid. All four wheels and the clutch did the same thing. I used up all the fluid and the reservoir is now filled to about 75%. It's well above the "Min" so I assume it's okay.

I assume that the old fluid and the Castrol mixed in the reservoir and some of the old fluid is mixed in with the new fluid. If this is what happened, then my question is... will the fluid boil at the old fluid's boiling point or somewhere in between the old and new fluids' boiling points?

Thanks!

[Lubo]

Originally Posted by Scuderia000

Well, I flushed my brake fluid for my first time... and the brakes stop the car with little to no fade so far.

I don't think it went as well as it should have though. For one thing it took hours, but the main problem was that the fluid never came out the color I expected. I was going to go with Motul RBF600, but I had already ordered Castrol SRF and it was too late to cancel it, so I just used it. I also decided against the ATE Super Blue as an indicator. The Castrol fluid looks completely clear. The fluid in my brake reservoir was brown and had junk floating in it! I just had my rear brake pads replaced at the dealer!

So here's what I did:
I wanted to make sure I didn't waste the Castrol fluid, so I suctioned out most of the fluid in the reservoir with a surgical irrigation syringe. I stopped when the old fluid was up to about the "Min" (minimum) mark. I put all the suctioned fluid in a plastic water bottle and marked a line at the fluid level to record this volume of fluid. I dumped out the plastic bottle into a glass jar for disposal somewhere (don't know where). I then poured in the Castrol fluid up to the "Max" arrow and hooked up and pressurized the empty motive pressure bleeder. I started with the passenger rear. At first the fluid came out dirty brown, then changed to a pale yellow, but it didn't come out clear. At this point I had reached the mark on the plastic bottle, so I decided to move on and avoid running out of new fluid. All four wheels and the clutch did the same thing. I used up all the fluid and the reservoir is now filled to about 75%. It's well above the "Min" so I assume it's okay.

I assume that the old fluid and the Castrol mixed in the reservoir and some of the old fluid is mixed in with the new fluid. If this is what happened, then my question is... will the fluid boil at the old fluid's boiling point or somewhere in between the old and new fluids' boiling points?

Thanks!

How many bottles did you end up putting in?

[e82n54]

I put in 1 bottle, which is 1 liter.

[Dackelone]

Originally Posted by Scuderia000

...
I assume that the old fluid and the Castrol mixed in the reservoir and some of the old fluid is mixed in with the new fluid. If this is what happened, then my question is... will the fluid boil at the old fluid's boiling point or somewhere in between the old and new fluids' boiling points?

Thanks!

Short answer is: somewhere in between.

Your new brake fluid (SRF) is dilluted with some of the old brown fluid. The only way to know at what point it will boil is to take a sample and you guessed it(!) boil (test)it!

I don't think anyone in the US has the brake fluid testers that they have over here in Germany. You are probably fine with your fluid. But IF it really bothers you you should bleed your brakes again - until the fluid come out clear.

[Lubo]

Originally Posted by Scuderia000

I put in 1 bottle, which is 1 liter.

Where did you find 1 liter bottle? I thought the SRF only comes in .5 liters.

If you want to do a complete flush you will need approximately 1.5-2 liters of fluid to flush the old one completely.

[Dackelone]

Originally Posted by Lubo

Where did you find 1 liter bottle? I thought the SRF only comes in .5 liters.

If you want to do a complete flush you will need approximately 1.5-2 liters of fluid to flush the old one completely.

These guys sell the 1L bottle.

http://www.oelwelt24.de/catalog/1+L....ng+Brake+Fluid

50 euros for a 1L bottle.