T100 Brake Booster Upgrade

I have a 2005 Tundra SR5 Access Cab. I do have ABS but the module is on the other side of the engine bay near the air box. My ABS was unaffected by this upgrade. I don't think this will work if your Tundra has VSC since that master cylinder is very complex.

Here is my before and after installing the T100 brake booster and Master Cylinder.
Before:
After:

Here are the links for the parts I purchased:
Brake Booster: https://www.ebay.com/itm/223112298169
Master Cylinder: https://www.ebay.com/itm/231091919940
Brake Fluid:

$20 BOSCH ESI6-32N Brake Fluid (Direct Replacement for DOT 3, DOT 4, and DOT 5.1) - 1 Quart

https://www.amazon.com/dp/B07338GQM8/ref=cm_sw_r_cp_apa_glc_fabc_9TZQ3T1DSA7Y76YWZCBZ?_encoding=UTF8
(This brake fluid is compatible with all DOT specs except for for 5. It also has the highest boiling point and will take heat better)

My reason for doing this upgrade was to both stiffen the pedal and to get ready for a front brake upgrade (GX460 Calipers and rotors). The pedal is incredibly stiff, touchy, and feels great even with the factory 2005 calipers.

I began by bench bleeding my master cylinder in a vice. This is to prep the Master Cylinder (MC) for the fluid and to make bleeding a much more simple task.

To remove the factory MC and Booster I removed these 4 nuts above the brake pedal inside the cab.
There is also a small shaft in between the center of these nuts with a pin and cotter pin that need to be removed. I didn't take a pic of it unfortunately.

After doing this, I unbolted the MC and removed it entirely. This allowed me to push the brake lines out of the way enough to slide out the booster. Be careful not to kink or damage any brake lines. The less they bend the better.

Once the factory booster was out, I measured the distance from the mating face of the booster to that cotter pin clip I didn't get a picture of earlier. In my case, the I needed to cut 1/4" at a minimum to about 1/2" at a maximum. I ended up bottoming out the clip on the new booster and cutting about 5/16" of the new booster's shaft to allow the clip thing to screw all the way down.
Before cutting:
After Cutting (I had to cut that last 1/16" of the shaft after taking this pic because it wouldn't fit):

When reinstalling, I wasn't able to and didn't need to reuse that aluminum spacer behind the factory booster. The only snag I ran into was in regards to this bracket.

The new booster studs were closer together than the stock one. I had to pinch and bend the bracket slightly to allow the holes to line up with the studs. This was done easily with a pair of adjustable pliers.
I was also able to stretch the brake fluid sensor plug underneath the MC enough to plug into the new reservoir (The new and old MCs use the same plug for the fluid level sensor).

After reattaching the two brake lines that connect directly to the MC, I was ready to bleed the brakes. Make sure you bleed in the correct order and absolutely ensure you bleed the LSPV that is above the rear axle against the underside of the truck bed. There was a lot of air in the lines and it took me an entire bottle of brake fluid to properly get the air out.

The correct bleeding order is: Rear right brake, rear left brake, LSPV, front right brake, and then the front left.

Here was the final product put back together including my oil catch can that is in the way.

 

Sub'd for future reference. Very nice sir. Love to hear an update after some further driving experience.

 

Thank you for doing this write up. It's crazy how much thicker that booster is. I bet she's going to stop very well.

What's the purpose of that port on the booster? Circled in blue.

 

That is the nipple the vacuum line attaches to. The factory one has one in the same place and it fits just the same too. The vacuum from the line that connects to that is what makes the booster actually boost the braking!

That booster is smaller but also thicker than the factory one because it has two diaphragms inside it. The factory one only has one. Two diaphragms definitely increase the boosting capability.

 

Great write up. Agreeing with @KNABORES on more drive time experience reports!

I'll be sticking this one in my personal sticky thread.

 

Thanks. When will you be installing the calipers?

 

My only concern is in regards to the lifespan of the cheaper parts. They are remanufactured and seem to have good reviews. If you can, it's always an option to buy OEM from the dealership. You know for sure the parts will be solid, but your wallet will be lighter for sure.

 

I will get them in this Friday and will likely have them machined the following week. I expect to tackle the brakes two weeks from now when all of my parts are in.

 

Nice! Excellent walk through.

I like the methodical approach of installing the Cylinder and Booster first to work out the kinks. Also lets you test apples to apples on the Calipers (old vs new) with the new system.

Looks like the lines matched up well? No flaring needed?

 

A couple more quick questions:

1) Is that Brake Booster a Double Diaphragm? (unclear in link)

2) Have you tried to test your brakes to activate the ABS System to see how the new components interact?

 

This is the part I'm wondering about too. In that old TundraSolutions thread they made it seem like it was necessary to match ABS MC with ABS equipped truck. It seems like that may not be necessary. There are only 2 ports on the MC and my understanding is that one is for the rear wheels, and one is for the front. It's not like there is a separate port just for the ABS.

I also thought it was great that @Thrussn didn't have to extend the wires for the brake fluid sensor like they claimed.

 

Great write-up, big thanks for doing this!

One thing that is a little perplexing though is that MC you used says it's for non-abs T100s and it's hard lines seem to connect just like your OEM Tundra with ABS....this one says it's for an ABS T100 and the front line connects on the top....

https://tinyurl.com/3k92whyn

I'm really interested to hear your experience with this. Maybe you could test the ABS function in the wet at some point? Thanks!

 

Ya. We saw the same things which is a good question. The 2002 ABS Module is off to the pass side like Thrussn 2005. The OEM BB and MC look identical to each other 2002 vs 2005.

 

Looks like you should go reread the thread.

 

@Thrussn post up part #’s that you see on your MC and BB parts please so we have specifics.

Quick search seems Reman’d is the only option on these Brake Boosters.

Master Cylinder options limited so Reman seems the way with these, as well.

 

Thanks! I read a lot of people will have the mushy pedal feeling with the GX460 brake caliper upgrade and figured I'd do this upgrade first. It gave be a solid before and after while also ensuring I won't have to worry about a soft pedal.

I didn't have to flare any brake lines or anything. The only brake lines I actually disconnected were these two.

I'm 99% sure it is a double diaphragm booster. I believe all T100s came with them, but don't quote me on that. I'm also pretty sure that thicker appearance combined with that slight step down on the boosters shape indicates it's double diaphragm as well.

I will be actively testing my ABS on a dirt road today and will follow up on it!

 

I did pull that harness wiring a tad tighter than you should. In my case, I didn't have to extend anything, but it would definitely be a more safe approach to do so.

I'll follow up on that ABS stuff today, but theoretically there should be no reason for it to stop working. The ABS module shouldn't even notice the swap since I didn't touch it at all.

 

Thanks. Yeah the BB looks DD like you say. Just was checking to make sure. Posted another parts list above and seems your Reman is the best route. Been on the phone a bit this morning so catching up on things here.

Nice on the flare line mate ups. I’m remembering another write up from somewhere where a guy did what you did, but ended up welding that BB plunger rod that you cut. Cutting seems way simpler and almost plug and play.

 

The only thing I would imagine is different between the MCs is the location of that front port. I'd imagine the job they both perform are identical and the actual ABS functions are performed by the seperate module. Perhaps the ABS MC you linked is different only to allow a more direct replacement for the vehicle it was designed to go in without bending any brake lines.

I also looked at the compatibility list of the MC I have and it has both abs and non-abs vehicles in the listing.
This is promising, but I'll put my money where my mouth is on a dirt road later today lol.

 

I'll be sure to see if I can find any part numbers on them. When ordering, I specifically ordered for a 95 T100 on both parts if that helps at all in the meantime.

 

I hope you are right, but I think you are mis-interpreting that chart. All the vehicles listed with no reference to ABS are vehicles that were never offered with ABS...the ones that are listed as "non-ABS" are listed that way, because ABS was an option for that model/year...and none of those are listed w/ABS

 

I'll update the thread when I find out

 

A far fetched idea to *maybe* solve the Fluid Level Wire Connection... reverse the seating of the rez 180°?

 

I thought the same thing as well as seeing if the stock reservoir would fit the new MC

 

Yeah. Thats a good one. I like a Mojo to Mojo connection. Old Mojo might work, but New Mojo may be better.

 

I just spent the last 30 minutes out on some dirt roads slamming on my brakes.

I was correct in my hypothesis and the abs still works just as good as it did before the swap. It didn't seem to have any issues at all after the endeavor as well. No leaks and the pedal felt like it normally does when the abs is activated.

 

@Thrussn thanks for being the guinea pig on this one.

 

First he converts his truck to 4wd, then he does the T100 swap that we were all afraid to try. If I could give an award I would.