Leaking from (sort of) master cylinder help

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Joined
Mar 4, 2018
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Location
St. Louis, MO
Was wondering if I could get some advice from people that have been down this road before. So my 100 started leaking brake fluid, found out when it left a substantial puddle in my driveway. It was leaking from the typical master cylinder area, so I ordered the rebuild kit and some grommets, and today I pulled the unit.

I believe what I've received is some bad news, hoping someone can explain this. See attached photos. The master cylinder itself is dry, nothing wet around the bellows, firewall is dry. The unit is wet underneath the black computer area and seriously wet under the rubber electrical terminal covers for what I'm guessing is the abs controller. Most of the lower portion is covered in this weird gelatinous brake fluid(?) flim.

Is the whole unit shot? If not, what do I buy to fix this?

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I think that looks bad. There are no replacement seals for that section. The corrosion is pretty advanced and would make me nervous even without the leak.
This will get you everything.
BRAKE BOOSTER ASSY, W/MASTER CYLINDER

If you think the Booster pump and Accumulator has life in it get this.
BRAKE MASTER CYLINDER SUB-ASSY
With the corrosion under there I wonder how long that pump will last.

Each of these have different part numbers depending on year of truck.
 
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I have not been down this road yet, but looks like it has been leaking for some time. Before re-install, I would scrape the surface rust and brush on some POR-15 or equal to the body and brackets to keep that rust from spreading. Hope you get everything worked out.
 
Not sure what year you have, but if you have a 1998 or 1999, here is an option.
It's $805 shipped and if you return your core, they refund you $300, so total out of pocket is $505 for the part.
This beats the heck out of $2000+ for a new one.
ABS Pump Master Cylinder Booster Actuator TOYOTA LAND CRUISER LX470 Stk L327F8 | eBay


Here's the 2000-2002 one. ($200 core credit)
ABS Pump Master Cylinder Booster Actuator TOYOTA LAND CRUISER LX470 2000-2002 | eBay

Here's the 2003-2006 one ($200 core credit)
ABS Brake Pump Master Cylinder Booster Actuator TOYOTA LAND CRUISER LX470 03-06 | eBay
 
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Thanks for the replies gentlemen. Based on this, and that I've read that its basically impossible for the black computer portion to leak, I've purchased a used accumulator/pump assembly. I'll rebuild the master and replace the rest, hopefully that will cover all the bases. I'll let you know how I get on.
 
Well, after a long saga, I believe this issue was the previous owner partially stripped one of the hard line connections to the master cyl, causing a slight weep that had coated the components below. The shop I took the truck to for an alignment must have banged that line and stripped it out the rest of the way, as that visit coincided with the massive leak. I put a timesert in the stripped connection and it appears fixed now (nerve wracking operation because I didn't want to ruin the $2000+ master cyl). I of course replaced the half rotten booster section with the mint looking used one I bought, and it is operating as intended.

I'm calling this one case closed.
 

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