Brake Booster/Master Cylinder Upgrade/Fix

Hi all,

I've got the infamous "unicorn" master cylinder on my first-gen Tundra. I took the unicorn, secondary MC piece apart and found what I believe to be the source of the issue--a warped seal.

I've been going back and forth debating on how I want to fix the thing--since I can't locate a rebuild kit and Toyota wants half my soul for the entire assembly--and I've been considering the T100 upgrade detailed here.

I was wondering if anyone has tried this upgrade with a DC pickup, as OP's truck has the access cab.

Or, if anyone has figured out another way to fix the issue without dishing out the $1,200+ that Toyota wants for the booster/MC assembly, I'd love to hear what you did.

Thanks in advance for any advice!

 

If this is the “unicorn” booster/MC you speak of, you’re going to have significant hurdles attempting the T100 upgrade. There’s a dedicated brake line to each wheel and they play into the “auto-LSD” dif we have. All that would have to go away and you’d have to learn to live with all the codes and lights on your dash when you get rid of it.

 

That's the VSC booster/MC and whatnot.

I think he's talking about the MC that's technically 2 pieces MC, with a standard booster. VSC have the little keg-can booster (or whatever function it serves)

 

I think that's the model with VSC. I should have mentioned that my truck does not have VSC. My issue is the same as the one discussed in this thread.

 

That is the unicorn DC with brake control system. I think you have to buy the entire booster/MC assembly
https://toyotaparts.ourismantoyotaofrichmond.com/oem-parts/toyota-power-brake-booster-472000c073

 

Yeah that’s what I’m trying to avoid doing if I can

 

Several lengthy threads about this past couple yrs. I don’t recall anyone posting a follow-up with a satisfactory solution other than BOHICA at parts dept