Braking Nightmare

If it happened right after the lift, it seems like something related to the lift would be the culprit. The master cylinder going at the exact same time seems highly unlikely.

 

I agree but I can’t for the life of me imagine what would throw it out of wack and actually cause a “check brake system” malfunction

 

My only total guess is that a brake line might be getting pinched in the suspension and as the truck goes down the road it's pinching and unpinching.

Can you read the computer codes off of it? Pretty sure the abs module can throw codes when its grumpy.

 

Try to dig and see what the "code setting" criteria for that malfunction is. Maybe someone has a subscription to some OEM data and can shed some light.

 

I just dropped it off at the dealer, I’m sticking around to talk to the tech so I don’t get a call in an hour saying they drove it and couldn’t duplicate the issue. My service manager said if they can’t pull any immediate codes they’ll have to open a case up with Toyota because it’s a safety issue... looks like I probably won’t be having my truck for a while, sigh

 

Update: service bled my brakes and state that they found an excessive amount of air in the system, adjusted rear drums and stated that the issue was resolved. Well it’s not resolved lol seems to point more and more to the master if you ask me. However the master tech said that by pumping the brakes and prompting the truck to kick the service brake system warning is normal because *apparently* pumping the brakes “fools the master cylinder into thinking there’s air in the system” is there any truth to that? I don’t believe so but again what do I know. Can anyone share any knowledge?

 

Update: for anybody still following, lines have been bled multiple times, rear drums adjusted, master cylinder changed (again) problem still persists... should we start moving towards an abs issue? any ideas?

 

If you're getting air in it somehow, there's got to be a leak somewhere. But usually those are pretty evident. Hmm. Time more moar coffee.

 

What if they put in the exact same master cylinder as a defective one during the recall?

Always makes me wonder during recalls which parts they’re using. How would you know if they got rid of all the defective parts in the warehouse and they’re using an updated one for a recall?

It’s the same part number. Even if the manufacturing dates are different, when was the cutoff dates for the new recalled part?

A lot to think about.

 

Well so that was a thought, but they just replaced it again for the second time so this would make it my 3rd overall master cylinder lol. Pedal feel is much better I won’t lie but problem still persists slightly where the pedal is different almost every time I step on it. They said next area they’re gonna start looking is in abs. No lights on the dash though and I figured that they would’ve been able to pull codes or run an electronic diagnosis on the abs. Truck still kicks service brakes warning when the pedal is pumped. Which the master mechanic said was normal because when you “pump the brakes you trick the master cylinder into thinking there’s air in the system”

 

Wonder if i should pump my brakes to see if this happens? But then if this happens it'll drive me nuts. I'm gonna let this one go lol.

 

Somebody on the Facebook groups gave it a shot for me and their truck did not kick the same error

 

Recall parts generally speaking do not have the same part number as the original part. Partly to avoid this concern, partly to allow different pricing to be used to reduce costs. That is the case here, where the original part number is 47201-041x0 and the recall part number is 04008-56x04.

It does keep recall stock separate from 'normal' stock though, which is a good thing, especially at the dealer level.

In my opinion, the better question to ask is what happens to non-recall part stock that exists. That is, parts that were in the supply line for regular replacement parts that may be sold at a later date. Generally speaking, Toyota will put a stop-sales code on the part number affected and then verify their stock using batch numbers and remove affected inventory. If it's a serious issue, they will generally issue a bulletin to dealers to quarantine their stock to verify it, or simply return it to Toyota if it is not easy to verify.

But then the question is, do they always do this for parts that had a recall. I'd like to think so, but I wouldn't be placing any bets on it, especially if it's not a safety-related issue.

There's another issue that I see creep up from time to time in engineering and manufacturing, and that is when an issue affects a certain part on one car and there is a recall for it, but the same issue continues to exist to a lesser degree in other parts/vehicles for years because it was outside of the scope of the initial engineering study, etc.

Getting back to the initial concern, there's little to no chance that any truck getting the recall completed would be using an older master cylinder, but there's a chance if the master cylinder was replaced outside of the recall that an older master cylinder could have been used. How likely that master cylinder is to have the issue depends on what Toyota's supply stock looked like when the recall was issued and whether any dealers had stock at the time (it is quite unlikely that any dealers would be stocking a part like this for a vehicle this new, but it's possible).

Jeff

 

Good info, just more to think about with these recalls. Also, concerns about replacing a part on your own like the crank position sensor which have been faulty. Owners will buy a new one on Amazon or eBay and could be just like the old one that shit the bed.

 

I pump the brakes many times based on traffic conditions and no dash alarms present.
If the brake problem started AFTER you lifted the truck check all brake lines (soft and hard) and all the connections. When I lifted my truck, I replaced all OEM soft brake lines with extended SS braided lines and bled all 4 lines till no bubbles were seen. Drove the truck for about 100miles and rebled the brakes. Never a problem or alarm.

 

Hey man, did you end up finding the issue?
After having a local shop changing my rotors and pads (bought my own), and flushing my fluid - I’m having exact the same issue. Brake pedal feels spongy, if I pump it few times - it gives the same exact error. Went to another shop to do another flush - no luck.
Truck is long out of warranty (2016), what could they possibly fuck up to cause the issue - no clue.
Was wondering what ended up being the cause in your case.
Much appreciated

 

I had an 80 series land cruiser and a vacuum valve on the brake booster went bad and was an easy fix. Just throwing that out there, not sure if it applies here at all.

 

Any info helps. Appreciate it man! Now having the shop to bleed the brakes once again, if won’t help - will have to visit the dealer , unfortunately

 

OP hasn’t been logged in over a year and a half. Doubt you’ll hear from him