caliper bleed screw leaking...?
#1
Rennlist Member
Thread Starter
caliper bleed screw leaking...?
right rear corner, outboard.
while washing car after my DE this past weekend, i noticed dried brake fluid trails/stains on the caliper stemming from the bleeder screw. however the rubber grommet (?? attached to the rubber cap) still looked wet with a bit of fluid. i tried to tighten it but seemed pretty tight already and i didnt want to over-torque it. i've not noticed this before and this is the 3rd DE since fluid change (i know, i know, i've been bad, ok?!?) so it's not like the screw has recently been opened, etc.
FYI: the reservoir is not overfilled and it doesnt look like i lost much fluid at all; i'm using pagid yellow pads with plenty of life left, on stock discs which are in good condition; the brakes performed fine on the track; i've driven since washing but no evidence of more leaking.
anyone had this issue? is there a...washer or gasket or whatever it's called, on the screw aside from the one which holds the protective cap on? is this normal from time to time under heavy track use?
any insight would be appreciated.
thanks.
while washing car after my DE this past weekend, i noticed dried brake fluid trails/stains on the caliper stemming from the bleeder screw. however the rubber grommet (?? attached to the rubber cap) still looked wet with a bit of fluid. i tried to tighten it but seemed pretty tight already and i didnt want to over-torque it. i've not noticed this before and this is the 3rd DE since fluid change (i know, i know, i've been bad, ok?!?) so it's not like the screw has recently been opened, etc.
FYI: the reservoir is not overfilled and it doesnt look like i lost much fluid at all; i'm using pagid yellow pads with plenty of life left, on stock discs which are in good condition; the brakes performed fine on the track; i've driven since washing but no evidence of more leaking.
anyone had this issue? is there a...washer or gasket or whatever it's called, on the screw aside from the one which holds the protective cap on? is this normal from time to time under heavy track use?
any insight would be appreciated.
thanks.
#2
Most likely just dribbled from last bleed. Brake fluid if not cleaned off quickly and completely will stain the paint of your caliper.
If concerned and want to be sure, you can dry area and pull rubber cap then have someone press firmly on brake pedal while you watch closely for any leakage. Most likely you will find not leaking.
If concerned and want to be sure, you can dry area and pull rubber cap then have someone press firmly on brake pedal while you watch closely for any leakage. Most likely you will find not leaking.
#3
There is no gasketing on the screw the parts catalog will confirm this. A long time ago on another car of mine this happened as the result of a stripped threads on the caliper. Somebody over tightened the bleed screw. What I'd do? Get the car in a safe place and loosen screw and have somebody pump brake just a little. This might flush out a bit of dirt causing a bad seal, retighten and cross your fingers. It's a long shot, probably won't work, but it's all I can think of. If that doesn't work, something's stripped or cracked or deformed.
Could also be some [insert expletive here] mischief maker with an 11mm wrench? Think about it: those screws are extremely easy to mess with! It's surprising more bulsh*t doesn't happen with them.
Could also be some [insert expletive here] mischief maker with an 11mm wrench? Think about it: those screws are extremely easy to mess with! It's surprising more bulsh*t doesn't happen with them.
#4
i have had this issue and it only leaks when on the track (cant be that hard on the brakes on the road)
basically if its leaking it was overtightened and you will need to rebuild or replace the caliper... its an expensive mistake
basically if its leaking it was overtightened and you will need to rebuild or replace the caliper... its an expensive mistake
#6
Rennlist Member
Thread Starter
(assuming it IS an actual leak,) yep, my first thought was "over tightened". but what i cant figure out is, if that's the case, why did the symptom just show up now? as mentioned, this is the first time i've noticed the leak BUT i have def done other events since the last bleed/last time i touched that screw. and i clean the car/calipers regularly, so i would have noticed before this.
in any case, i will have someone press the brakes while i look at it. also, i plan on changing fluid this weekend anyway, so will keep an eye on it afterwards and esp at the next event.
thanks all...
in any case, i will have someone press the brakes while i look at it. also, i plan on changing fluid this weekend anyway, so will keep an eye on it afterwards and esp at the next event.
thanks all...
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#8
Race Director
This happens due to the brake pressure at the track. The bleed screw was either over tighten or or some fluid leaked out at a bleed and was not thoroughly cleaned off the caliper. Something like this happened on my 07 but I never had an issue on the street or track.
After a year (around 10 de's or so) and your threshold braking and really using the brakes they will start to turn a dak red to dark maroon due to heat. This happens but you will need to rebild the calipers, replace the seals and dust boots. At that time you can look into the possible fluid leak.
After a year (around 10 de's or so) and your threshold braking and really using the brakes they will start to turn a dak red to dark maroon due to heat. This happens but you will need to rebild the calipers, replace the seals and dust boots. At that time you can look into the possible fluid leak.
#9
Race Director
#10
Rennlist Member
Thread Starter
#11
Teflon tape (plumbing tape) is a bad idea in my "guy-on-the-internet" opinion.
1. It is designed for use on tapered compression-fitting pipe joints. It will reduce friction during installation of such pipe joints so a firmer compression fit can be established with NPT (tapered thread) joints. The tape itself isn't necessarily what seals the joints, the tape facilitates the production of massive pressures of the compression fit along the tapered threads which is what does the sealing.
2. On a brake caliper bleed screw it makes no sense as far as stopping leaks or dribbles bypassing the threads because the seal on the screws is at the base or seat of the screw and comes up thru the drilled center. Also, there is obviously no tapered thread on a bleed screw making teflon tape basically unworkable in the way it was intended.
Then again? Try it and see if it works. I could be wrong.
1. It is designed for use on tapered compression-fitting pipe joints. It will reduce friction during installation of such pipe joints so a firmer compression fit can be established with NPT (tapered thread) joints. The tape itself isn't necessarily what seals the joints, the tape facilitates the production of massive pressures of the compression fit along the tapered threads which is what does the sealing.
2. On a brake caliper bleed screw it makes no sense as far as stopping leaks or dribbles bypassing the threads because the seal on the screws is at the base or seat of the screw and comes up thru the drilled center. Also, there is obviously no tapered thread on a bleed screw making teflon tape basically unworkable in the way it was intended.
Then again? Try it and see if it works. I could be wrong.
#12
No way use teflon tape. It would take the heat but as mdrums indicated, you don't want to risk a piece breaking off and going somewhere that requires a major rebuild. Bleeder screws are designed to seal with no tape or other sealant.
1) Confirm there is a leak - probably just staining from poor cleaning after prior bleed
2) If there is a leak try a new bleeder screw, if that doesn't resolve issue seek professional help
My money is on staining from poor cleaning after bleeding and some track heat accelerating the staining. Common problem.
1) Confirm there is a leak - probably just staining from poor cleaning after prior bleed
2) If there is a leak try a new bleeder screw, if that doesn't resolve issue seek professional help
My money is on staining from poor cleaning after bleeding and some track heat accelerating the staining. Common problem.
#13
Burning Brakes
Just a heads up, sealing on the bleeder screw doesn't occur at the threads. The head is tapered and is the sealing surface. When it's tightened down, the pointed head of the screw blocks the hole at the bottom of the caliper. When you twist it off a little it opens up the hole and allows fluid to pool around the unthreaded base of the screw and into the hole in the side and through the hollow centre.
Teflon tape, even if there wasn't an issue, wouldn't help. If there's a sealing problem you have to repair/replace the caliper. Take the screw out, examen the surface at the screw and in the hole. Clean it well and replace the screw if there is any question as to the quality of the sealing surface.
Good luck. I hope it's a simple fix.
P.S. I'm with the others that think it's just remnants from a previously uncleaned bleed, but keep an eye out incase! In my experience when a brake component goes, it goes BAD and is clearly a problem.
Teflon tape, even if there wasn't an issue, wouldn't help. If there's a sealing problem you have to repair/replace the caliper. Take the screw out, examen the surface at the screw and in the hole. Clean it well and replace the screw if there is any question as to the quality of the sealing surface.
Good luck. I hope it's a simple fix.
P.S. I'm with the others that think it's just remnants from a previously uncleaned bleed, but keep an eye out incase! In my experience when a brake component goes, it goes BAD and is clearly a problem.
#14
Rennlist Member
Thread Starter
i plan on bleeding the system this weekend. i'm just baffled as to why the symptom showed up only now (as stated, i clean my calipers after every event or every 2 wks, whichever first, and havent bled them or touched the screw since april).
ok, stupid question alert but...how do i back out screw all the way to examine it without fluid getting all over the place or at the very least, constantly draining into a bottle? i.e. 1/2 turn is usu enough to get it flowing, i can imagine it's worse/messier if the screw is backed out completely.
ok, stupid question alert but...how do i back out screw all the way to examine it without fluid getting all over the place or at the very least, constantly draining into a bottle? i.e. 1/2 turn is usu enough to get it flowing, i can imagine it's worse/messier if the screw is backed out completely.
#15
Rennlist Member
Just a heads up, sealing on the bleeder screw doesn't occur at the threads. The head is tapered and is the sealing surface. When it's tightened down, the pointed head of the screw blocks the hole at the bottom of the caliper. When you twist it off a little it opens up the hole and allows fluid to pool around the unthreaded base of the screw and into the hole in the side and through the hollow centre.
if one would have to replace whole caliper every time bleeder is messed up world would run out of calipers long ago.