Just finished flushing the brake fluid on our 2013 Civic LX. The master cylinder cap has a lot of wiggle to it after tightening it as much as possible (unless I am missing some trick involved in it's tightening). Is this normal? I find it hard to believe that this could be normal !
loose master cylinder cap
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Originally Posted by Lubener
Does it leak past the cap? Every cap I have seen was a tight fit. Get a new one, can't be very expensive.
No leakage
. I will be getting a new cap. The thing is, though, it's a very simple arrangement of the plastic cap and the gasket, and they both look perfect.
Does it leak past the cap? Every cap I have seen was a tight fit. Get a new one, can't be very expensive.
No leakage
. I will be getting a new cap. The thing is, though, it's a very simple arrangement of the plastic cap and the gasket, and they both look perfect.
cap might have swole up over time or made wrong (high side of tolerances) from day one.
Originally Posted by toad
Just finished flushing the brake fluid on our 2013 Civic LX. The master cylinder cap has a lot of wiggle to it after tightening it as much as possible (unless I am missing some trick involved in it's tightening). Is this normal? I find it hard to believe that this could be normal !
It's hard to answer your question because "a lot" and "wiggle" are highly subjective terms.
Some small amount of rotational movement is normal. Maybe 5mm in each direction. I know because I've had a lot of Civics (2009, 2011, 2015 to name a few), all of them use the same master cylinder (or very close). The important thing is the cap does not wiggle vertically, if you can lift the cap up that's abnormal. Once you tighten it fully it is normal for the cap to have some rotational play though before it hits the stop that prevents it from tightening any more or the stop that starts loosening it.
If it's anything more than that check the cap carefully, there's a track the lips on the cap are supposed to ride, eventually the track forms an angle to force the cap to tighten downward.
Just finished flushing the brake fluid on our 2013 Civic LX. The master cylinder cap has a lot of wiggle to it after tightening it as much as possible (unless I am missing some trick involved in it's tightening). Is this normal? I find it hard to believe that this could be normal !
It's hard to answer your question because "a lot" and "wiggle" are highly subjective terms.
Some small amount of rotational movement is normal. Maybe 5mm in each direction. I know because I've had a lot of Civics (2009, 2011, 2015 to name a few), all of them use the same master cylinder (or very close). The important thing is the cap does not wiggle vertically, if you can lift the cap up that's abnormal. Once you tighten it fully it is normal for the cap to have some rotational play though before it hits the stop that prevents it from tightening any more or the stop that starts loosening it.
If it's anything more than that check the cap carefully, there's a track the lips on the cap are supposed to ride, eventually the track forms an angle to force the cap to tighten downward.
Is there a missing o-ring ? Can you add an o-ring to fix it ?
If the Cap is made of 'plastic', could it have a hair-line crack in it.
If it does, it would look normal, but not tighten completely.
Buying a 'new' Cap would be the quickest fix.
There may even be 'after-market' Caps available at AZ, AAP
If it does, it would look normal, but not tighten completely.
Buying a 'new' Cap would be the quickest fix.
There may even be 'after-market' Caps available at AZ, AAP
It should pull up tight. Being that your Civic is a 2013, this seems odd.
Was it tight when you removed it?
Was it tight when you removed it?
Are you sure it is not like a gas cap where you reach a tight point and then there is some free-play. Ed
Originally Posted by NoNameJoe
Originally Posted by toad
Just finished flushing the brake fluid on our 2013 Civic LX. The master cylinder cap has a lot of wiggle to it after tightening it as much as possible (unless I am missing some trick involved in it's tightening). Is this normal? I find it hard to believe that this could be normal !
It's hard to answer your question because "a lot" and "wiggle" are highly subjective terms.
Some small amount of rotational movement is normal. Maybe 5mm in each direction. I know because I've had a lot of Civics (2009, 2011, 2015 to name a few), all of them use the same master cylinder (or very close). The important thing is the cap does not wiggle vertically, if you can lift the cap up that's abnormal. Once you tighten it fully it is normal for the cap to have some rotational play though before it hits the stop that prevents it from tightening any more or the stop that starts loosening it.
If it's anything more than that check the cap carefully, there's a track the lips on the cap are supposed to ride, eventually the track forms an angle to force the cap to tighten downward.
The movement is vertical but small, perhaps 1.5 mm. I was able to see the track the lips ride on and the cap was right up against the hard stop.
Originally Posted by toad
Just finished flushing the brake fluid on our 2013 Civic LX. The master cylinder cap has a lot of wiggle to it after tightening it as much as possible (unless I am missing some trick involved in it's tightening). Is this normal? I find it hard to believe that this could be normal !
It's hard to answer your question because "a lot" and "wiggle" are highly subjective terms.
Some small amount of rotational movement is normal. Maybe 5mm in each direction. I know because I've had a lot of Civics (2009, 2011, 2015 to name a few), all of them use the same master cylinder (or very close). The important thing is the cap does not wiggle vertically, if you can lift the cap up that's abnormal. Once you tighten it fully it is normal for the cap to have some rotational play though before it hits the stop that prevents it from tightening any more or the stop that starts loosening it.
If it's anything more than that check the cap carefully, there's a track the lips on the cap are supposed to ride, eventually the track forms an angle to force the cap to tighten downward.
The movement is vertical but small, perhaps 1.5 mm. I was able to see the track the lips ride on and the cap was right up against the hard stop.
Originally Posted by MasterSolenoid
If the Cap is made of 'plastic', could it have a hair-line crack in it.
If it does, it would look normal, but not tighten completely.
Good Idea but I could not find one.
Buying a 'new' Cap would be the quickest fix.
There may even be 'after-market' Caps available at AZ, AAP
Even Rock auto does not carry it.
If the Cap is made of 'plastic', could it have a hair-line crack in it.
If it does, it would look normal, but not tighten completely.
Good Idea but I could not find one.
Buying a 'new' Cap would be the quickest fix.
There may even be 'after-market' Caps available at AZ, AAP
Even Rock auto does not carry it.
Originally Posted by Eddie
Are you sure it is not like a gas cap where you reach a tight point and then there is some free-play. Ed
There is some rotational free play built into the thing as someone else mentioned, but I wouldn't expect vertical free play.
I last flushed the brake fluid 3 years ago and I remember that it was loose then. The interesting thing is that the rubber membrane in the cap was pulled inward by just the amount I would expect from 3 years of caliper pad wear suggesting that the reservior was sealed
Are you sure it is not like a gas cap where you reach a tight point and then there is some free-play. Ed
There is some rotational free play built into the thing as someone else mentioned, but I wouldn't expect vertical free play.
I last flushed the brake fluid 3 years ago and I remember that it was loose then. The interesting thing is that the rubber membrane in the cap was pulled inward by just the amount I would expect from 3 years of caliper pad wear suggesting that the reservior was sealed
Originally Posted by Gebo
I just finished changing the brake fluid on my cars and my LS400's cap was a little loose as well. I just got it snug and let it go. Let us know if the new cap fixes it.
Will do. Might take a while as it seems to be a dealer only item, and I would bet they would have to order it. If they needed one quickly they would probably pull one off a master cylinder in stock and replace it later.
I just finished changing the brake fluid on my cars and my LS400's cap was a little loose as well. I just got it snug and let it go. Let us know if the new cap fixes it.
Will do. Might take a while as it seems to be a dealer only item, and I would bet they would have to order it. If they needed one quickly they would probably pull one off a master cylinder in stock and replace it later.
Is the inner screen assembly inside the reservoir? As far as I'm concerned when you lock the cap down, the seal is actually being created between the rubber on the underside of the cap and the plastic assembly inside the reservoir with the screen. There's a bit of sealing occurring between the rubber diaphragm and the wall of the reservoir at the mouth but not much.
If the plastic assembly inside the reservoir is missing, the rubber would not have anything to push against when the cap is sealed and the cap would move a little vertically.
If the plastic assembly inside the reservoir is missing, the rubber would not have anything to push against when the cap is sealed and the cap would move a little vertically.
![[Linked Image]](https://www.bobistheoilguy.com/forums/attachments/usergals/2019/10/full-69841-37696-img_7027.jpg "[Linked Image]")
Originally Posted by NoNameJoe
Is the inner screen assembly inside the reservoir? As far as I'm concerned when you lock the cap down, the seal is actually being created between the rubber on the underside of the cap and the plastic assembly inside the reservoir with the screen. There's a bit of sealing occurring between the rubber diaphragm and the wall of the reservoir at the mouth but not much.
If the plastic assembly inside the reservoir is missing, the rubber would not have anything to push against when the cap is sealed and the cap would move a little vertically.
The inner screen assembly is in place. I had to remove it to suck out the old fluid, then I put it back in.
Is the inner screen assembly inside the reservoir? As far as I'm concerned when you lock the cap down, the seal is actually being created between the rubber on the underside of the cap and the plastic assembly inside the reservoir with the screen. There's a bit of sealing occurring between the rubber diaphragm and the wall of the reservoir at the mouth but not much.
If the plastic assembly inside the reservoir is missing, the rubber would not have anything to push against when the cap is sealed and the cap would move a little vertically.
The inner screen assembly is in place. I had to remove it to suck out the old fluid, then I put it back in.
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