Hi everyone. Because of the costs of the ABS pumps on some hybrid Toyota vehicles, I have seen some customers, of previous repair shops, asks the repair shop to modify or removed an existing bad ABS pump actuator, and instead, make the braking system to work as a normal conventional system as seen in none hybrid cars. What I have noticed with such jobs when they come to my shop, is that the brakes usually are dammed hard like a rock. You need to apply more efforts for the brakes to work. Secondly, I have noticed that only when the ICE is operating, that's when the effectiveness of the brakes comes on. But as long as it reverts back to electric, the brakes are much harder to apply(I already know why that is so: lack of vacuum being provided to the brake salvo mechanism.... during electric drive). If I were the one doing the modifications, I'd sourced for electric vacuum pump, that would operate same time, despite which mode is in operation. Here's my question: With ABS pump actuators disconnected or replaced just with wholly a hydraulic system of operations, WOULD THE REGERATIVE BRAKING STILL WORK TO CHARGE THE BATTERY? IS THERE ANY NEGATIVE IMPACTS TO THE BATTERY(IN TEMS OF CYCLES)?
Yes, it's possible. Problem is the brakes needs hard application for it to work well. Costs of the ABS pump makes people disengaged the electronic parts, and just make do with the hydraulic braking.
The electronics (the brake/skid ECU) is what sends the message to the HV ECU to say "hi , a little regen here would be nice", so I can't imagine much regen going on if that isn't happening.
What I'm trying to day is, does the regen still work, if the abs pump module at the hood area is none functional?
Well, you've given an extremely vague description of how some local Nigerian mechanics have somehow jury-rigged around a brake system that was designed to work with a non-boosted master cylinder, an electric pump, a stroke simulator, no direct fluid path from the master cylinder except to the front wheels only and then only in fail-safe conditions, and these mechanics have somehow made this thing act as if it is a regular car with an engine-vacuum master cylinder booster (what did they do, add one behind the master cylinder). You've offered no explanation of what parts of the system these mechanics have changed or altered or wired around in order to make any of this happen. I can only answer in the most general terms: the brake electronics are what request regen from the hybrid electronics, and what amount, and how to coordinate the two systems. If the brake electronics have been bypassed somehow, or put into fail-safe mode, as it certainly sounds like they have, they will not be coordinating with the hybrid electronics or arranging for any regen to occur. One other point is that if the system is operating in fail-safe mode, unless these other mechanics have somehow done a lot of other plumbing, there will be no braking except at the front wheels, and that may affect the stability of the car in a turn.
Now you for my jinx. What they have done is just to make some plumbing works at the brake master area, with only the front brakes working. Rears are electrically operated, I know that. Your explanation has answers my curiosity. Thanks Chap!
