Failed brake servo/pedal simulator - a how-to DIY fix

[Drlinkin]

You bought a used unit from a Jazz? Who’s to say it won’t fail in a couple of months either?

Absolutely nothing of course, however if I am right in my suspicions and the brake fluid in the donor car was bled frequently, fully and correctly then the part may not fail. I guess it’s the chance I took compared to the cost, back order time and associated misery with the dealer!

The robust preventive action of course is a rebuild with new sensors and potentially seals more tolerant of moisture-rich brake fluid.

That, and main dealers doing what they’re paid to do obviously!

[Drlinkin]

Really pleased the guide has been of interest to you guys here; and I hope it helps person x in the future who for one reason or the other needs to complete this DIY fix.

[tencherman]

I, for one, appreciate the hard work Drlinkin - cheers.

[EEEE]

Excellent write up, thanks for taking the time to do so.

It's a little disappointing that ECU testing didn't have a jig to test it (I guess its relatively new component/ecu) , it would have been great if they could have replaced the sensors or at least one of them. The pressure sensor should be relatively 'standard' , but admittedly the stroke sensor less so. It seems strange that both the pressure and the stroke sensor was at fault? perhaps the stroke sensor is in fact just another pressure sensor in a different fluid path?

I too share your concerns regarding the brake fluid change procedure. I had terrible trouble getting a firm pedal (actually, impossible to achieve) after changing discs/pads on the wifes 10th gen (2017) honda civic.

The ABS modulator (or VSA vehicle stability actuator I believe its called) was stuck in the 'reduce pressure' mode, with pedal pressure bleeding off into the accumulator, after 1 inch of pedal travel, the brakes worked fine. no amount of 2 man manual bleeding, pressure bleeding or vacuum bleeding fixed it. In the end , by deduction id worked out that one of the valves in the modulator block must be stuck by debris/rust. IcarSoft Pro to the rescue. 1 button press later to jiggle the ABS valves, and the issue was gone. Pedal perfect. I was actually surprised. I still have my doubts about the modulator block (I think slowly the issue returns), i suspect infrequent changes to fluid or incomplete changes are partly to blame.

The method you describe of reusing the block but transplanting the brains is also mentioned on the 10th gen civic forum. As the Civic platform is very wide ranging in terms of market and configs, the ECU is highly configurable (weight, wheels size, body type etc etc), but the valve block/actuators are all the same. To avoid having to recode to the car specifics, you can just re-use the existing ECU with a donor valve block as you have done. In this particular case, the block has known problems with valves getting stuck, almost certainly not helped by incomplete brake fluid changes.

My e is now also out of warranty (just), so I think I will start preventative maintenance with a full brake fluid change!

[HeartNotHead]

Dear DrLinkin,

What an amazing post. I am really grateful to you for going to the trouble; and to see from the also very helpful replies above that I am not alone. I have been informed by my Honda dealer this morning that my "brake pedal simulator set” has failed. The bad news is that the total cost of getting me back on the road will be £2871.74. The dealer is requesting a contribution from Honda UK. The good news is that the part is showing on the Honda UK system as in stock and available for delivery. We shall see.

My e (white, 16” wheels, advance) has 18k on the clock, was delivered in September 2020 and has had three annual services. It is now out of warranty. I love it despite - one flat tyre which required two new tyres to fix and five days off the road; three new door handles, all under warranty; and several episodes of the 12v battery dying inexplicably. And as for range - hopeless and rarely more than 100 miles unless I drive at funeral cortege speeds.

I will report back once the matter is resolved and in the meantime, if anyone has any advice it’d be gratefully received.

PS my user name was chosen when I bought the car. Very apt - such a shame Honda, having done so much right with the car, has let us and themselves down so badly.

[MattHero]

The good news is that the part is showing on the Honda UK system as in stock and available for delivery. We shall see.

It is? That's great news. I and a load of others are waiting on these to arrive at dealers right now, so fingers crossed they arrive soon.

Honda stumped up 40% of the part cost in my case, but won't make any contribution to labour for out of warranty cars (so far, who knows if this will change...).

[HeartNotHead]

Many thanks. That’s likely to be the ‘offer’ to me too I understand.

[Jerseyboy]

From researching various reports around the internet and reading the detailed description on how to repair the brake servo it is obvious that what happened to my car is a common fault that was in the car when it was built. My garage are having difficulty with Honda UK in getting them to increase their offer of 40% of cost of unit. They believe this is because Honda UK is managed from Germany who have not sold many Es or Jazz their market is CRVs etc.
My question is why hasn't anyone suggested a class action against Honda because it is a fact that Honda Japan did a recall knowing what the problem was but Uk and Europe didn't is this not putting all their purchasers at risk? My car suddenly stopped responding to the brake pedal and the steering became very heavy had my wife been driving it could have been serious,

[SF999999]

A class action would be great…..
one hasn’t happened IMO, because UK customers are handling this issue individually. My Jazz is impacted but the only useful information I found so far is in this thread within the eHonda forum.

[londiniumperson]

From researching various reports around the internet and reading the detailed description on how to repair the brake servo it is obvious that what happened to my car is a common fault that was in the car when it was built. My garage are having difficulty with Honda UK in getting them to increase their offer of 40% of cost of unit. They believe this is because Honda UK is managed from Germany who have not sold many Es or Jazz their market is CRVs etc.
My question is why hasn't anyone suggested a class action against Honda because it is a fact that Honda Japan did a recall knowing what the problem was but Uk and Europe didn't is this not putting all their purchasers at risk? My car suddenly stopped responding to the brake pedal and the steering became very heavy had my wife been driving it could have been serious,

Well, as you've been effected and have suggested a class action action against Honda, why don't start the ball rolling and do this yourself?