07-29-2019, 08:00 PM
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#16
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Quote:
Originally Posted by jeech
Hey guys, I just did a TBU last weekend, but the brake pedal travel was pretty bad, almost to the floor. I got it into a local shop that got good reviews, and they're telling me that I might have gotten air into the ABS system when I did my flush, and that they'll need to bleed the ABS and adjust the brake push rod. They're quoting all of this at several hours over the initial quote for a brake system flush ($411 vs $140). Now granted, I haven't don't a brake bleed/flush since I was about 14, so I'll be the first to admit I probably did a sub-par job. But this seems a little steep for the work they're talking about doing.
Am I getting had?
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I went back to stock calipers because I chased this problem for a year. I tried everything but I could never really get rid of the soft pedal. I even rebuilt the master with new piston seals. the new piston seals made the problem better but the pedal was still softer than I like.
after I went back to brand new stock sized calipers the pedal is perfect, so the only thing that was different for me was the calipers. I honestly think the TBU is a terrible idea for the older trucks.
if you have an 01-02 you have a completely different braking system than the 96-00 trucks. the 01-02 do have the special bleed procedure for ABS.. not sure what year truck you have?
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07-29-2019, 08:12 PM
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#17
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I'm putting a larger master cylinder in. :/
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07-29-2019, 08:38 PM
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#18
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Join Date: May 2013
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Quote:
Originally Posted by eimkeith
I'm putting a larger master cylinder in. :/
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I upgraded to the master and booster off the 4x4 T100. I have tip toe brakes now. They get a little softer when the rears come out of adjustment since the auto adjusters quit, but when everything is tight it's stupid how hard it stops with a solid pedal.
Having had the TBU on two different truck and setup with the stock hydraulics and the T100 stuff, I really think that this mod shouldn't be done without the full upgrade. Always had to do the double pump on the stock stuff, not an issue with the new MC and booster.
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07-29-2019, 08:58 PM
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#19
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It makes sense that the 231's will not feel right in our trucks, that's a lot more fluid to push with a master cylinder not designed/sized for that. So I think
@ eimkeith
is on the right path with the bigger master cylinder
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07-31-2019, 10:49 AM
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#20
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Alright, here's where I landed.
Since the truck was with them already, I went ahead and let them bleed the ABS system. Between the additional bleeds and adjusting the rears and the push rod, the brakes are golden! I know there's speculation that the stock master cylinder doesn't have what it takes to drive the larger calipers--from what I can tell right now, that's not the case. My brakes are nice and stiff now, and engage right where I'd expect them. Could a bigger master cylinder further improve the brakes? Maybe. But I'd say the TBU with 231mm calipers is just fine with the stock one.
Thanks everyone for the suggestions and the sanity check!
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07-31-2019, 10:55 AM
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#21
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Quote:
Originally Posted by 4Runner4Leon
It makes sense that the 231's will not feel right in our trucks, that's a lot more fluid to push with a master cylinder not designed/sized for that. So I think
@ eimkeith
is on the right path with the bigger master cylinder
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please elaborate. the calipers between the tundra and 3rd gen t4r look the same in size. its also not like your jumping up in piston size either. im under the impression most of the issues come from improper bleed proceedures (see post 20).
picture for reference:
https://www.yotatech.com/forums/atta...rabrake022.jpg
t4r caliper on the left.
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07-31-2019, 11:29 AM
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#22
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This is why I don't recommend the TBU. I had the same issue on one of our 3rd gens, and could never get the pedal close to stock feel. Braking never gave me the confidence that I had prior to the TBU.
Good luck, OP!
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07-31-2019, 11:34 AM
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#23
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Quote:
Originally Posted by mesooohoppy
please elaborate. the calipers between the tundra and 3rd gen t4r look the same in size. its also not like your jumping up in piston size either. im under the impression most of the issues come from improper bleed proceedures (see post 20).
picture for reference:
https://www.yotatech.com/forums/atta...rabrake022.jpg
t4r caliper on the left.
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Read this for a very thorough comparison between stock and tundra brakes: Hard to find Specs, Info & Measurements on 231mm 13WL Tundra Calipers & Rotors
Edit: If you haven't already try using this 3rd Gen specific google search: https://www.google.com/search?q=site...hrome&ie=UTF-8
Type what you're looking for after all the info that's already in the search bar.
Last edited by Bad Luck; 07-31-2019 at 11:36 AM.
Reason: Added Info
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07-31-2019, 11:44 AM
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#24
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Quote:
Originally Posted by jeech
Alright, here's where I landed.
Since the truck was with them already, I went ahead and let them bleed the ABS system. Between the additional bleeds and adjusting the rears and the push rod, the brakes are golden! I know there's speculation that the stock master cylinder doesn't have what it takes to drive the larger calipers--from what I can tell right now, that's not the case. My brakes are nice and stiff now, and engage right where I'd expect them. Could a bigger master cylinder further improve the brakes? Maybe. But I'd say the TBU with 231mm calipers is just fine with the stock one.
Thanks everyone for the suggestions and the sanity check!
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Glad they sorted it out for you.
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07-31-2019, 11:45 AM
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#25
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Quote:
Originally Posted by absalom
This is why I don't recommend the TBU. I had the same issue on one of our 3rd gens, and could never get the pedal close to stock feel. Braking never gave me the confidence that I had prior to the TBU.
Good luck, OP!
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so did you try to fix the issue, or did you just go back to stock?
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07-31-2019, 11:54 AM
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#26
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Quote:
Originally Posted by Bad Luck
Read this for a very thorough comparison between stock and tundra brakes:
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i have been doing some research and i still need to do more. but from what i have been reading, my take away is that the bleed procedure has a lot of do with the success of your tbu swap. if you stave the MC, it eventually ends up starving the abs unit, which can be a pain to bleed (from what ive read, also common on other toyotas).
a fair amount of the people who arent satisfied with the swap claim they werent happy with the pedal feel and went back to stock; most of these i come across on this forum do not further elaborate.
the measurements on the first link you showed me do in fact confirm the tundra caliper is bigger overall (but not by much). which would likely mean that there is slightly more passage length for the fluid to reach the piston; although i wouldn't think this would require a larger MC. these calipers really arent that much larger and you arent jumping up in pistons either.
sorry for not multi quoting. it doesnt seem to work on this forum.
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07-31-2019, 12:14 PM
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#27
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Quote:
Originally Posted by eimkeith
I'm putting a larger master cylinder in. :/
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Decided upon which one yet?
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07-31-2019, 12:18 PM
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#28
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Official Vendor
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Quote:
Originally Posted by TonyB66
Decided upon which one yet?
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Yeah I bought it about a year ago or so - let me check my records and see what the part number was. I got the corresponding booster as well.
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07-31-2019, 12:23 PM
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#29
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@ mesooohoppy
When I did mine I purchased an assortment of silicone caps to cap off the brake lines to keep from losing too much brake fluid. Worked like a charm
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07-31-2019, 12:27 PM
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#30
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I hate my tundra brakes so much. Like Jeremy Clarkson hitting a laptop with a hammer level of hate.
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