Brake Issue After Changing Pads

Hey guys!

I just changed the front brake pads on my 2018 Off Road.

I now have code C1452 "Low Accumulator Pressure" and braking issues.

When parked, repeated applications of the brake causes dash lights to blink and beeping.

When driving, it seems like the ABS trips out causing irregular braking (but no dash lights or sounds).

We have an Autotel code reader and tried using it to clear the air from the braking system, along with the good old fashioned brake pumping to clear. Neither have fixed the problem.

Fluid levels are good.

Had issues getting the pins out but that shouldn't have messed the caliper up (I don't think?).

Changing my brake pads shouldn't have broken the hydraulic braking system...

Help!

Here's a video of the problem: https://youtube.com/shorts/YIU7m0ixb90?si=LkQuH7FOaU9sB-nz

 

Pretty normal as the accumulator needs to build up pressure.

 

We ran it through a pressure building/brake bleed cycle using the code reader that took about 20 minutes. That should have built sufficient pressure, no?

 

Bump. Anyone?

We've tried bleeding the system multiple times but it's still not working properly.

TYIA

 

Video seems like no pressure at pedal. Did you follow the service manuaL procedure, or old school two-man, pump+bleed? (Sorry, I don’t have link to the procedure)

Did you do all four wheels? Does the brake unit bleed the rears automatically, as it should?

if you introduced air into the system, it can be difficult to bleed, you may need a vacuum or pressure bleeder.

 

Thanks for the reply!

We first did a manual two man bleed (pump three times, hold on fourth). Then we used our Autel scanner to perform the VSC bleed. It bleeds the VSC system 25 times. Then did the air bleed on the Autel. Still have a spongy brake pedal.

 

It sounds like you still have air in the system. Check out post #4 in this thread: https://www.4runners.com/threads/brake-bleeding-problems-please-help.42139/


5th Gen is same procedure as 4th Gen.

 

Thanks for finding that thread!

Looks like the only difference in #4 compared to what we were doing is to do one front brake and repeat the bleeding process until all air is out of that one line before moving on to the next.

Will give it a shot! Willing to try anything at this point!

Looks like you need a special tool to do the pressure bleed. Will have to go pick that up for next steps.

 

UPDATE:

We ended up taking the brake calipers off again and resetting the pistons.

After resetting the pistons, we did another manual 2 person brake bleed.

We changed our technique from:

1. bleed front right x1;
2. bleed front left x1, and
3. repeat as many times as seemed necessary;

to:

1. bleed front right as many times as necessary until we saw air come out; and
2. bleed front left as many times as necessary until we saw air come out.

It took approximately 4-5 times per side. Did not redo the backs.

This seemed to fix the problem.

Bonus: From all the messing around with the brakes we ended up having to replace the ABS/speed sensor line on the left side because Bert started throwing that code after we got the brake bleed sorted.

Problem appears to be fixed now.

 

Glad to hear your got it figured out.

 

Why did you open system to just replace the pads?

 

We were in the process of replacing the rack and pinion, and while we had the calipers off and out of the way decided to replace the pads.

Just depressed the pistons then installed the new pads.

Not sure if you consider that opening the system? We did manual bleeds and Autotel bleed after I took it for a test drive after putting it back together and something was clearly wrong. Assumed air must've gotten into the system somehow.

 

Ah, missed the part of calipers coming off. I just worked on my pads last night-cleaned and relubed pins, backing plates, etc. I just squeezed the pistons in a bit with pliers. Reason I asked.

 

Fair enough! Yeah, we're not sure why Bert made things difficult. We had the calipers off for a few days to get the rack and pinion done and we didn't re-press the pistons before putting it all back together, so maybe the pistons relaxed unevenly while they we're off it's a mystery! Shouldn't have been that difficult haha.