My booster and MC are all crusty rusty (calipers and rotors are bad too). There is a 95 T100 at the local junkyard with a new looking booster/mc and I’d probably get it for $50 or less. Is there any downside to this? I’m not looking for performance improvements. Just think this might be a better way than buying an aftermarket booster and MC. I know I’ll have to bend the brake lines and require the cap but can’t see any other issues. I plan on symticking with stock calipers and rotors.

 

the MC is designed to work with calipers with a specific piston surface area (volume) in order to operate correctly. if the MC you swap in isn’t matched to your components, the braking action might surprise you: either grabby/lockup braking action, or excessive pedal effort needed to apply them.

 

At that price point, you might buy it just to try it out and see how it does. Some of the 1st Gen Tundra guys retrofit to the T100 booster to solve some of their braking issues, so these things do get swapped around to a decent extent. The trucks aren't that different in weight, so I bet there's a good chance you can get it to work out. The worst behavior is when the rear brakes lock before the front brakes and they truck tries to swap ends. You can dial back the LSPV if that happens. I'd probably give it a try. If you really want to have fun, grab the calipers and rotors from the T100 while you're there and try to transplant everything.

Editing the reply. There was a related thread where somebody did the T100 booster and MC in a 4Runner and had success. Somebody else used T100 rotors and calipers with the stock MC/booster in another 4Runner. That's a good sign that at least everything bolts together without a lot of modification.