Brake Gremlin

[werminghausen]

Finally Success!

I changed all the calipers and the brakes are just great....as it should be on a Toyo.
Its not as crisp as with a Mercedes or Porsche but so much better than everything I had before.

Looking back I had two main issues and the two coincided unfortunately and got me confused big time.

Issue #1: seized brake caliper pistons (on these crap 3 year old NAPA remanufatured calipers with heavy corrosion underneath the boots which led to hard to no piston movement. 2 of the 8 front pistons where entirely frozen... and all the rest of the pistons were at least hard moving with a thick layer of corrosion.

The frozen calipers not only made the brake almost unusable with a super soft brake pedal but also this lead to unusually short intervals for the brake motor to come on (every second time).

[It was NOT the master brake cylinder leaking as some people thought.]

Issue #2 ABS/TRC brake alarm

This alarm drove me nuts and to this day I don't know what this was about.... how it started. With the new hydro booster at least this alarm went away.
It might be some contamination inside the ABS block but who knows.


I have a smile now braking.....again

Thanks for all you help and suggestions.

Martin

 

[SocalSam]

That's great news. I don't recall seeing any report of uneven rotor and pad wear. I do recall calipers being rebuilt. Most of the thread focused on the booster module and alarm. We did correctly deduce that it was more than that. In either case, this repair took way longer than it should have.

 

[MikeinNH67]

Good to hear you have solid brakes now. This goes to show that the calipers on these are the first thing to look at even if only a few years old.

 

[werminghausen]

Yes exactly, calipers are a weak spot.
I had reman calipers (Napa) installed and I believe that the powder coating was exceptionally bad. After 3 years the coating flaked off. I don't care about the coating but around the boots it created a leak and water seeped through the boots and cause corrosion at the outer ring of the pistons. The inner facing pistons were in much worse condition compared to the outside pistons, probably due to the increased rate water spraying on the inside vs outside?
If you notice a decline of braking power there is a high chance that the pistons in your calipers don't move freely...and that needs to be corrected.

I think the most confusing part of the brake disaster was the coincidental occurrence of the ABS alarm with the other brake problems.
I was probably not clear enough in my reports in this thread that I had noticed a decline of brake power and spongy pedal about one year before the initial brake failure (fluid leaking due to rusted out rear brake line- and causing the brake alarm).
I agree with Sam.... it took way too long to fix and that was mostly because of the missing knowledge about the hydro booster and its electronics/ECU.
The OBD scans are not easy to interpret, at least not for me. I was not able to find the root cause of a failure inside the ABS/TRC block... At least that was the root cause for me if I understand correctly. Maybe the disassembly and cleaning of the block may solve that issue but it is easier to say after I installed a brand new unit. Installing a new unit was not my first choice but needed in that situation because I was lost with chasing this ghost. The problem was clearly not the relays that I know now. The relays bust have been a result of a ABS block failure (not knowing what exactly failed there causing the electronic turmoil).

I can only hope that someone finds this thread helpful in the future.

Martin