Where could this leak be coming from?

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songzunhuang
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Where could this leak be coming from?

Post by songzunhuang »

Ok, I have a leak and I cannot seem to locate the source. The fluid is red in color, which leads me to believe that it is transmission fluid (dextron III stuff also used for power steering and the brake bomb), but the location has got me scratching my head. The drips are spotted at the bottom of what appears to be the master brake cylinder. You can see the brake bomb on the bottom right in the picture below. This is shot looking up to the bottom where you can see the red fluid forming another drip.
Fluid leak dripping from brake master cylinder?
Fluid leak dripping from brake master cylinder?
Dextron III Leak.png (1.9 MiB) Viewed 11252 times
I cannot for the life of my understand why that red fluid would be accumulating in that spot. It's clearly not brake fluid.
It leaves a sizable spot under the car each day. I've been watching it for days and a drip forms every day. I've looked around for signs of fluid being flung or leaking from any high pressure power steering hoses and none seem to be wet with fluid. Anyone have any ideas?
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Song Huang
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jps635
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Re: Where could this leak be coming from?

Post by jps635 »

May help
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olympia57
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Re: Where could this leak be coming from?

Post by olympia57 »

This may , or may not , be a silly question based on where you live , but do you use red antifreeze in your cooling system ? if so taste the drip to see if it is sweet.
You certainly should have a corrosion inhibitor in your cooling system .
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Re: Where could this leak be coming from?

Post by 86_6series »

Coming from #1

https://www.realoem.com/bmw/enUS/showpa ... Id=34_0296

Have Jay rebuild it for you, he's the best.

viewtopic.php?f=24&t=28245
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songzunhuang
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Re: Where could this leak be coming from?

Post by songzunhuang »

Thanks everyone, that makes sense now. I didn’t realize the brake bomb also routed to the master cylinder, but after seeing the picture it makes sense. Ok, I’ll look up Jay!
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Song Huang
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Re: Where could this leak be coming from?

Post by songzunhuang »

olympia57 wrote: Mon Dec 30, 2019 2:28 pm This may , or may not , be a silly question based on where you live , but do you use red antifreeze in your cooling system ? if so taste the drip to see if it is sweet.
You certainly should have a corrosion inhibitor in your cooling system .
Don
Don, definitely not anti-freeze. I use that Xerex gold stuff in my cooling system. Goodness knows I’ve bought many gallons of that!
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sansouci
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Re: Where could this leak be coming from?

Post by sansouci »

Song,
Definitely let Jay Stratton rebuild your booster with new seals. Also suggest you contact Bill Fox (Max Lumens) [email protected] for the machined aluminum seal carrier to replace the plastic one and then send it with your booster to Jay.
One assembly tip: fit the hydraulic lines to the M/C and booster BEFORE you reattach it the firewall. Then there is some space to drop the ball under the booster and tighten it. It is a blind operation and small hands work best.
Also, I think there is a ceramic filter in the bottom of the reservoir that can be replaced easily.
Happy New Year
Best,
Ken
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Re: Where could this leak be coming from?

Post by songzunhuang »

sansouci wrote: Mon Dec 30, 2019 9:32 pm Song,
Definitely let Jay Stratton rebuild your booster with new seals. Also suggest you contact Bill Fox (Max Lumens) [email protected] for the machined aluminum seal carrier to replace the plastic one and then send it with your booster to Jay.
One assembly tip: fit the hydraulic lines to the M/C and booster BEFORE you reattach it the firewall. Then there is some space to drop the ball under the booster and tighten it. It is a blind operation and small hands work best.
Also, I think there is a ceramic filter in the bottom of the reservoir that can be replaced easily.
Happy New Year
Best,
Ken
Thanks for the tips. I've reached out to Jay and will await his response. Also, I already purchased the ceramic filter in preparation for when I do all this work. I hadn't heard about the aluminum seal carrier. I'll have to dig a bit more about that.
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Song Huang
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Re: Where could this leak be coming from?

Post by zinnocoupe »

I used a booster rebuilt by Jay and it all want very smoothly. Jay has excellent instructions included with his rebuilt boosters as well. That was a few years ago and no leaks at all. I hadn't heard of the aluminum seal till now though.
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Re: Where could this leak be coming from?

Post by sansouci »

Zinnocoupe: It's not a seal but a "seal carrier" that is shaped like a plug. Jay said it's not necessary, but what the hell, I was preparing for the worst. Cheaping out on brakes and brake parts is foolish. It goes in the servo unit. See realoem

!https://www.realoem.com/bmw/enUS/showpa ... Id=34_0296
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Re: Where could this leak be coming from?

Post by songzunhuang »

zinnocoupe wrote: Wed Jan 01, 2020 5:02 am I used a booster rebuilt by Jay and it all want very smoothly. Jay has excellent instructions included with his rebuilt boosters as well. That was a few years ago and no leaks at all. I hadn't heard of the aluminum seal till now though.
Just ordered the aluminum carrier for the seal (from: [email protected]) as recommended earlier in this thread. It was $60 and includes the seal already installed in the carrier. The seller was super responsive and I ordered it at about 11:34pm PST on 12/31/19. It was his last order of the year! lol!

This will save me a lot of trouble and the stress of having to dremel out the old brittle plastic part and worrying about it breaking. It'll also allow me to avoid one of the custom tools that Jay describes in order to pull the old seal without breaking the brittle decades old plastic carrier. I figured for $60, it's well worth it.

As usual, I'll document all this when I install it. I'm still waiting to get a reply from Jay so that I can get the rest of the seals for the booster unit. OK, thanks everyone and Happy New Year to you!
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Song Huang
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Re: Where could this leak be coming from?

Post by JCS »

Hi Song,

You already have my website link, if you want to order a seal kit, all you need to do is send the money to my PayPal account,

Best,
Jay
'88 M6, Red/Tan
My NEW Website https://www.jaysbmwparts.com/
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Re: Where could this leak be coming from?

Post by songzunhuang »

JCS wrote: Tue Jan 07, 2020 4:43 pm Hi Song,

You already have my website link, if you want to order a seal kit, all you need to do is send the money to my PayPal account,

Best,
Jay, sent you payment to your PayPal as requested. FYI - I send a few questions to your hotmail account (associated to your PayPal) and didn’t get any response. I wasn’t sure if it was still active. Anyhow, since you answered here I sent along payment.

One caveat. I ordered the aluminum replacement part for the brake booster as recommended by another forum member. That came with the seal and a O-Ring (See image below). I think your kit may have redundant parts for those. I don’t know if it’s matters, but I guess I don’t really need those pieces anymore. Feel free to omit them from the kit you send me. Thanks and I look forward to eliminating this pesky leak.
AlumBooster
AlumBooster
4445F4B0-2E06-44E4-A2B8-5553167029E3.jpeg (269.1 KiB) Viewed 10945 times
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Song Huang
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Re: Where could this leak be coming from?

Post by zinnocoupe »

OK this is interesting I haven't ever seen anything about this "seal carrier" before. I'll be watching to see how this all goes Song. Just for the record I just got a rebuilt booster from Jay and only had to re&re the unit and send the old one back to Jay. I did it the lazy way . LOL .
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Re: Where could this leak be coming from?

Post by JCS »

songzunhuang wrote: Thu Jan 02, 2020 2:48 am

As usual, I'll document all this when I install it. I'm still waiting to get a reply from Jay so that I can get the rest of the seals for the booster unit. OK, thanks everyone and Happy New Year to you!
Dear Song,

Please check your own messages next time before you mention that I did not get back to you, in written post, on a Forum
I e-mailed and told you to check my website, as info ordering a kit is there.
I also asked previously if you had a daily driver, and you did not reply.

Jay
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Re: Where could this leak be coming from?

Post by songzunhuang »

JCS wrote: Fri Jan 10, 2020 7:27 pm
songzunhuang wrote: Thu Jan 02, 2020 2:48 am

As usual, I'll document all this when I install it. I'm still waiting to get a reply from Jay so that I can get the rest of the seals for the booster unit. OK, thanks everyone and Happy New Year to you!
Dear Song,

Please check your own messages next time before you mention that I did not get back to you, in written post, on a Forum
I e-mailed and told you to check my website, as info ordering a kit is there.
I also asked previously if you had a daily driver, and you did not reply.

Jay
Jay, no negativity intended, it seems we’ve been chatting via Facebook messenger, regular eMail and also this forum in private and public. At the time I posted that message, I didn’t see anything in email, which is where I sent the original message. Also, I can’t find a reply from you with regards to further questions I had after reading your photo site. I also can’t seem to locate a message asking about my daily driver, but again, maybe just too many message platforms crossing paths. I figured given the timing (around Xmas / New Years) you may have been on holiday.

So I noticed you were active on the public forum and used that as the next logical place to try. It seems we both check here. In any case, I went ahead and ordered your booster seal kit by sending you a PayPal. I look forward to getting it so I can fix that darn leak.

Perhaps something got mixed up in all those various forms of communication.

====< Wednesday, January 15, 2020 >====
I received all the o-rings from you today. I'll be all ready to attack this project this weekend and stop the stains in my driveway. Thank you.
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Song Huang
1984 633CSi
Last 7 of VIN: 6997383
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