Norcal Spotted and BS Thread

Yea i have an 01, fb marketplace guy has a 96 4R with Mc and booster.

I have an issue where I swapped (and bench bled) the Mc, Tundra Calipers (oriented correctly) and bled the system multiple times. I know I missed the bpv but we ran a ton of fluid through, amd beforeni commit to a purchase, i need to bleed again. The issue is that with the motor off, pedal is firm and holds strong. With the motor on, pedal drops to the floor and there is no feel to it. Like beyond spongy. Old mc did it too but no nearly as noticeable, and i changed it because pedal that drops slowly=bad mc typically. Even with some air id expect the soft feel but a bit of resistance. If the mc was bad, it would drop slowly with the engine off. This is unsafe to drive. And im trying to figure out my options

 

Is there a benefit to the dual diaphragm? And any info on the bpv dial?

 

IDK if it’s a coincidence but 2 guys I know personally did the TBU and hate it. Brake worst than the Tacoma. Yes, I know, the Tacoma brakes are smaller but somehow it brake better. I drove both and can confirm.

 

A dual diaphragm will generate more force vs a single.

 

If you don’t want to modify, you need to source a single. They typically go for 50-70 buck on marketplace. A dual from a 4R or pre00 Tacoma, you will need to modify the push rod and brake pedal setup to engage the push rod. Simple to do IMO but that depends on your skill level and comfort.

 

Is there a write Up on this? Im pretty handy but would like to know more

 

And idk, I didn't really have any issues with the tbu. I felt like I had a noticeable improvement on 33s and I can lock up the 35s. Idk whats wrong in my system right now but i need to figure something out... the only things left oe are the booster and wheel cylinders. Everything else has been touched.

 

Do the 1Gs have a proportioning valve? My pickup had one and the brakes were super goofy after upgrading the booster. I ended up pinching the return line from the rear with some vice grips and it definitely helped.

I did something with the valve on my jeep too but I don’t recall right off the bat what I did. Need to look at it again. I think I bypassed it when I went to disk in the rear.
Good luck!