Hydraulic Brake Booster Troubleshooting - 2012 OR

Hey guys. I've done some searching on this but can't find a straight answer.

My 2012 DCSB TRD OR has the hydraulic brake booster (instead of the traditional vacuum one).

I've had the truck for two years and the brakes have always seemed to require more force at the pedal than other vehicles. I chalked it up to being the rear drums, but I just had the annual inspection for registration and the inspector called out that the pedal engages high and the power isn't what it should be. He drives a Tacoma as well and says the brakes should be much more powerful.

From reading on here it sounds like these hydraulic assemblies do go bad. What I'm having a hard time figuring out is how to troubleshoot it.

Does anyone have a diagnosis strategy here? Is there a fuse I can remove to disable the pump and confirm that it's not working?

It sounds like from this thread that the part is actually fairly easy to replace (if you can source it), with a specific (and tool free) bleed procedure.

Has anyone been down this road before? Thanks in advance!

 

Following have similar issues also have a couple threads Ive started and a couple other OP hving similar issues…

My issue is same as yours but get a intermittent brake drag feeling havent been able to figure it out yet Have tried multiple things but the one and only thing that seems to help is bleeding brakes per FSM with good results sometimes it works for a week or two and others makes it worse…. Been very aggravating lately it makes me want to sell it sometimes… But have way to much money and time invested in it….

Best bet is to get ahold of a fsm and tech stream and a weekend of going down the list of testing procedures…

iIf you need any of the diagnostic procedures from the FSM I most likely have them and can get you a copy if need be..

best of luck and dont hesitate to reach out if you need any help. Ill try and find the other threads that I have used to help also.

 

I too was having an issue on a '14. Hooked up the tech stream and found out that the hydraulic unit was also generating a code. The problem was cured with a new assembly. But that thing is ghastly expensive even if you do it yourself.

The most common problem IMHO is the solenoid and that is also what the code was pointing to on mine. However, that thing alone priced out to be about 2/3 the cost of the entire assembly + my pressure pump seemed out of spec as it always read on the extreme low side. But the solenoid may affect that.

At the time the entire assembly w/o the tubes could be purchased separately as 3 sub assemblies so I worked the math and ended purchasing those and reassembling all using the old tubes removed from the original unit. Saved several hundred but ToyMoCo may have gotten wise to doing this by now....

 

Yea me and you chatted a while back about this issue. Im assuming you got around to installing the new one…. Did it fix the issue? Whats pressure does your pressure read now with the new pump?
I want to make the purchase but hate to do it and it not fix the issue. Since I cant find a definate part failure….

 

Yes, I remember the exchange. All was fixed with the new. It been awhile since I hooked up the tech stream but IIRC the pressure was more in the mid range.
What is a bit concerting, maybe yes maybe no, is the part with the new solenoid came with a new part number. Seems like I was able to track the new part number to now being used on 12+ models. I wonder why the change?

 

Thanks for the details y'all! Sounds like figuring out a copy of Techstream will be my next step.

Did either of you have ABS warning lights on during this process? I do not, so curious.

I've also heard that the solenoid is often the culprit, and that it's theoretically rebuildable, but also even the parts for that are expensive. Any chance you have that part number recorded? It being used on 12 different models might help my chances of finding on at a pick-n-pull.

Thanks again all!

 

The issue with the solenoid is it seems to have been the same part number for many of the trim packages up to 2011(??) or thereabouts as I recall from my increasingly foggy memory...

Afterwards the part number seemed to become specific to a particular trim package. For example, my 2014 6-speed TRD OR with tow package calls for a different solenoid for a truck without the tow package, and so on. Its why I did not provide any part numbers.

Oh, and I had to back-order the part. From the time of purchase until I received the thing seems like it was around 6 months(?). But that is when all the supply chain news was nonstop. I hope it much better now.

 

Would you mind posting the part number(s) you bought?

There aren't a lot of us, but there must be other 2014 V6 4.0 6-speed TRD OR owners like me -- who also have the tow-package option. Thanks.

 

@GilbertOz
For your trim pkg. only, same as mine, here are the part numbers.

Be advised that there is also a ToyMoCo part number on the solenoid itself but when I attempted to locate I was told it was an internal number only between Toy and Advics. I will get that to you later as it is too cold to go look.... Remind me if I forget.
____________________________________
- Complete Assembly,
Includes Everything Below
and all tubes, mountings 47050-04102
____________________________________
- Solenoid 47217-04091

- Brake Fluid Res
and Master Cyl
Includes Solenoid 47025-04092

- Booster, Accumulator
and Pump 47070-04021

 

I had a similar problem with my wife’s 2011 Ford Escape, harder than normal pedal, and occasional hot brake smell. Ended up being
the rubber brake hoses on the front calipers must have had an internal collapse. Replaced both sides, bled front brakes and problem solved.

 

About to pull the trigger and order the one for my truck but wanted to make sure Im getting the correct one? My truck 2012 trd offroad auto with trac and tow package
this pn# 47025-04081 I believe this one is without the accumulator

pn# 47050-04101 is the complete assy

Do I need the entire assy or can I get by without the accumulator???

That is if you dont mind verifying I got the correct PN for my truck

thanks appreciate it.

 

@toytaco112
PM me with your VIN and I will see what comes up.

 

Sent