What have you done to your 1st gen Tundra today?

https://youtu.be/vzO8K9sS7Do

 

You saying my posts are usually sub par?

 

Rude

 

You post any more videos like that, im gonna blame you when i cut my exhaust off.

j/k thats the good stuff right there, keep ‘em comin’.

 

You have to weld the v band flanges to the pipe. The flanges are just a nice flange that can join together and allow rotation if needed (unlike 3 bolt flanges). You can take them apart and bolt them back up without having to swap any gaskets too. Nice for somebody who might run a test pipe instead of a cat on race day, then put their cat back in to daily drive. Not exactly necessary for a daily drivers but the ability to clock them does make fabricating an exhaust easier.

 

Where soothing voice?

 

Sounds mean!!

 

No computer or phone clip does any of these justice

 

I have a question for you nerds. We've all seen it stated that you can damage an old Master Cylinder when bleeding brakes if you push the pedal too far.

Shall we assume the same could be possible when bench bleeding a new Master Cylinder? Especially a Chinese Raybestos unit that may have been on a shelf for a while?

 

I thought the concern of going too far was because you’re pushing a plastic seal past the normal usable bore into a chunk of unused bore. A new or remanufactured MC should have a clean bore all the way through, so no ‘ring ridge’.

 

That would make sense to me too. But I can tell you that after inspecing my 18 year old master cylinder, it looked new inside. I just wonder if I damaged something when plunging my new one.

I'm at a loss as to what I should try next with my brakes. I'm tired of talking about it and I know you all have to be tired of hearing about it. If PHM was around he would yell at me and post his crazy pills GIF.

 

My bad mc had a clean bore, too. But one of my seals had a scratch in it. Plug the mc and see if it’s holding pressure?

 

there’s gotta be a weak link somewhere in the system. Brakes are relatively simple. Pedal, booster, Reservoir, lines, pistons. Does yours have ABS? I’ve heard some of your struggles on here, but can’t remember if you’ve taken it to a brake shop or the dealer for a shake down?

 

Refresh my memory.
You followed FSM path during your last bleed, including LSPV?
You double-checked rear drums to ensure the shoes are barely engaging the drums?
You're positive there's no kinks or other fuck-ups in the lines?

 

And that one guy who posted about doing a hard brake to activate ABS to flush air from the octopus? Was that @FirstGenVol or someone else?

 

Truck does have ABS but fuses are pulled due to false ABS activation that started before I did the 14WA caliper swap. Put fuses back in and "burped" ABS on gravel multiple times now, then drove home and bled. I paid Budget Brakes to bleed them twice with no change. I even asked Empty Lord if he thought it would be worth letting a Toyota dealer bleed them and he said it wasn't likely to help. I'm willing to pay someone to fix it but I'm just not sure who to take it to.

Yes. I've probably bled the brakes 10-15 times since this started in October 2020. Never once did I get a large amount of air bubbles out after the initial few pumps.

Yes, last month @jpink came over and we rebuilt my rear brakes with new OEM parts(sans 1 self-adjuster Toyota discontinued) Then we adjusted per the FSM including adjusting the bell cranks and taking slack out of the parking brake.

Nothing that I have found. If there was, I'm not sure it would explain why I can build pressure after pumping once. I would think if I had a leak I wouldn't be able to build pressure at all.

 

That was me after it was recommened by a few people here. The first time I did it, it seemed to help but it was short lived.

 

I'd hate to tell anyone to replace new part with new part, but if you know 100% it's not the booster, and you're positive all bleeding is being done correctly and there's no air in the lines, I'd be second-guessing the MC also.

PHM posted something a long time ago related to brakes, back when I commented "it seems like the pedal is a hair softer some mornings when I first start the truck to leave after it sits overnight". He gave a set of diagnostic instructions, I think from the FSM, which explains how to test whether the booster was borked. Hell if I can find it now though.

That said, I'm curious if you've been through the braking diagnostics stuff in the FSM?

 

I couldnt find piston size of the 13wl, but the googles says 14wa has 48mm pistons. Larger pistons would apply less pressure for the same input pressure.

 

Are we confident you have the correctly-sized MC? If it's undersized, you'll have a long pedal that you can pump up.
Also, do these trucks have flowback valves? There was a time when disc/drum vehicles had a 2psi flowback for discs and 10psi for drums to make sure the cylinders/pistons don't retract too far making for a long pedal that needs pumped up.

 

I believe I've done all the ones people have shared here in the past. My booster passes the test in the FSM and I so does the check valve on the booster. That said, @Tundra2 told me that his booster passed the test but it was shot. So I question the validity of that test. I'm tempted to try the T100 swap but I also don't want to add more variables into the mix.

That was the initial suspicion by @assassin10000 when I first made the swap but numerous other members have done the 14WA swap without issues.

The fact that I can pump the pedal, and then on the 2nd pump it's firm, and brakes extremely well leads me to think it has to be one of two things.

1) either my "new" master has an internal leak
2) there is air trapped somewhere that I'm compressing in the first pump

I don't know what else it could be. I wish Toyota had not disconitnued the Master Cylinder. It makes no sense why they would do that but continue making things like window trim.

 

Good question.I believe both say 13/16 bore on them and it bolted right up like the OEM unit I removed.

 

That really sounds more like the rear brakes are not properly adjusted or seated. If you can get a firm pedal, the system is holding pressure, less likely it's a leak. Could still be air in the system, but sounds like you've bled it ad nauseum. Check those rears again. Make sure the assembly is correct and that the pads are adjusted properly for drag. Then check the LSPV to ensure it's engaging appropriately. My $0.02

 

It was your feedback from previous posts that made me decide to rebuild the rear brakes. I wrote last month that I adjusted them to the point that I could both hear and feel the shoes dragging. I actually went to far on one side and could barely spin the wheel so I had to back them off a hair and redo. The parking brake works very well too. I don't know what else I could do for the rear. Like I said, we even adjsuted the bell cranks just like the servive manual states. We did all this to JPinks Double Cab and his pedal feels great. He let me drive it. The only difference is he has 13WL's.

 

Can someone do some of that hydraulic math that I'm supposed to know, but don't...

To figure out the pressure requirements of the rear drums independently, and all three sets of calipers independently?

Then do some of that bore math to finger out how much PSI you're supposed to be getting out of the MC?

LEAVE it to the REDNECK to bring up math.

 

Here's what the FSM says about the truck brake PSI under load.



I've been thinking about buying that special service tool and then making it a rental for Herr since it pretty much only applies to our trucks, but I'd never get my money back on it.

09709–29018

 

I'm pretty sure they're about to discontinue the window trim also, FWIW. That's why I bought my spares.

I'm wondering if they're only intending to continue supporting (keeping in prod) the brake bits which are most commonly shared across most models. Your truck had the oddball MC, I think?

Anyway, I'd be suspicious of the MC, regardless whether it was new or reman. Why would the booster go bad immediately after you swapped the MC and calipers? But I hate throwing parts at stuff so I'm keeping my mouth shut.

 

So quick googling yields that SST goes anywhere from $650 to $1,200. Yeesh.

Anyways, I wonder if my harbus freightimus oil pressure guage would fit any of the brake lines???