Brake System Leak - advice needed

Wheels, Suspension, Brakes & Tyres questions and answers

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inventiv

Brake System Leak - advice needed

Postby inventiv » Sat Jul 21, 2012 5:17 pm

Hey fellow MX5ers,

I'm wondering if someone who has experience with this sort of thing could please offer some advice...

I have sprung a leak - ok maybe a couple:

https://skydrive.live.com/?cid=d65706d9 ... 17AA%21160

The main one is indicated by the red arrow. In fact when I push down on the brake reservoir lid, I can see the fluid seeping out at that black rubber gasket and also, a few air bubbles moving about in there. The leak marked with a green arrow on the master cylinder seems to be drier, so not sure if the fluid is traveling away from the red arrow down that way or if it's a leak of it's own.

Can someone shed some light on what I new brake master cylinder costs, and if a new reservoir tank and gaskets in question would come with it to replace the leaking ones? Or will I in fact need a new one?

What are my options to have this fixed? Am I up for a new master cylinder assembly or can this be repaired?

I want to play it safe (this thing helps stop the car after all) but I'm not keen on spending stooopid money :mrgreen:
I'm limited to having someone fix this for me as I have no experience with this sort of stuff.

It's an NA6 by the way.

Any advice is appreciated :beer:

inventiv

Re: Brake System Leak - advice needed

Postby inventiv » Sat Jul 21, 2012 5:29 pm

I've oploaded a video to clarify:
http://www.youtube.com/watch?v=X3oQ-Pi3 ... e=youtu.be

Has anyone else run into this problem?

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Locutus
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Re: Brake System Leak - advice needed

Postby Locutus » Sun Jul 22, 2012 12:28 am

the black rubber seal/bushing that joins the reservoir to the master cylinder does have it's own mazda part number, but i don't know if they sell it separately. for the NA8 the part number is 49-686B, but i don't have a NA6 parts catalogue handy. perhaps simply try disassembling your unit and giving all the sealing surfaces a good clean and inspection?

to replace the whole unit:
http://www.mx5parts.co.uk/brake-master- ... p-795.html
sit down before ringing a local mazda dealership for a price.

you might want to get that firewall resprayed while you're there. :shock:

inventiv

Re: Brake System Leak - advice needed

Postby inventiv » Sun Jul 22, 2012 8:57 am

Thanks for the info. Yup, the Mazda stealer is off limits, I have no interest in getting taken for a ride.

Ha ha, yes that part of the firewall will get some attention before the new stuff goes on. I believe autobarn stores can mix paint up and package into aerosol cans.

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Zcootz
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Re: Brake System Leak - advice needed

Postby Zcootz » Sun Jul 22, 2012 11:10 am

Sometimes the dealers are cheaper than the chain stores for that kind of stuff. I've found that with my other car for things like seals.
With two laps to go then the action will begin, unless this is the action, which it is.
Murray Walker

inventiv

Re: Brake System Leak - advice needed

Postby inventiv » Sun Jul 22, 2012 12:04 pm

Ok so I'm going to attempt this first:

http://www.ebay.com.au/itm/370505911501 ... 1438.l2649

Hopefully that solves it. I'll keep everyone posted.

Cheers

inventiv

Re: Brake System Leak - advice needed

Postby inventiv » Sun Jul 22, 2012 5:03 pm

Zcootz wrote:Sometimes the dealers are cheaper than the chain stores for that kind of stuff. I've found that with my other car for things like seals.


Ok good call. I'll call Mazda tomorrow morning. Might save on delivery time too if they have them.

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inventiv

Re: Brake System Leak - advice needed

Postby inventiv » Thu Sep 06, 2012 11:30 pm

Problem solved. It was the rubber seals for me. The ones that join the plastic reservoir to the cylinder. Cheap enough fix in the end, deffinitely replace these first if you think your master cylinder is faulty as the rubber seals cost pocket change.

Just a heads up to those who do end up tackling this job:
1. The plastic reservoir is a b*tch to get off. I started by pulling gently, moved on to pulling harder, then yanked on it like there's no tomorrow, then got a screw driver and tried to pry it away, nothing worked. In the end I reserved myself to the fact that I might break it to get it off so I just put it on the ground, placed my foot on the cylinder to hold it down and pulled upward on the plastic tank as hard as I could. With some considerable effort it did come off that way. Not that I'm recommending this method to anyone, but just wanting to let people know that this might be on the cards for others as well. Mine did not break, in fact I found the plastic to be quite good quality considering it is 20 odd years old.
2. You will lose enough fluid both in the cylinder and the reservoir that you will have to flush your break system fully. Both up at the master cylinder, and at all four calipers. It's not as daunting as it sounds. It's the first time I ever did it and after a couple of YouTube videos and a full Saturday taking my time it was easily done. Well worth it too, my brakes feel much better.
3. An enclosed spanner is a must for the metal brake lines.
4. Don't let the brake fluid touch any paint. I left the fluid drop onto the paint in the engine bay and over time it has lifted it off the car (see photos above). I spent most of the day prepping and repainting the engine bay under the brake cylinder. She's all new now.

Thanks to everyone for their input.
:beer:

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nGtim
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Re: Brake System Leak - advice needed

Postby nGtim » Sat Oct 06, 2012 2:16 pm

Hi mate, good to hear problems solved!
I'm running into the exact same issue. However on inspection when I changed my pads,
noticed the seal was broken so I know what I'm up against (I think).
Where and how much did you purchase your replacement seals?

nGtim.
http://www.dtpanels.com.au/ | | kits . panels . paint

inventiv

Re: Brake System Leak - advice needed

Postby inventiv » Sat Oct 06, 2012 2:36 pm

Go to eBay mate. It was $5 or so from miatamecca in the states. Took a couple of week to get here but ive used them often and they never dissapoint.

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