Is there a way to test the ABS pump?

#1

Hello!
I recently picked up a SE30 that was built by the prior owner but then never actually ran…So, I am the one doing all the shakedown work on the car over a few broken track weekends (three days prior to then pandemic and one since). To date, that has meant replaced wiring harness, replaced front caliper (because girling on one side and ATE on the other), new brake reservoir, and oh yeah, replaced the motor :joy:

At VIR this past Friday I managed to get a bit over zealous going into turn 4 resulting in complete lockup on my passenger front (outside to the corner if unfamiliar) and a nice flat spot on my tire. I was driving extremely poorly at this point and definitely stabbed the brakes vs squeezed (no attempt at threshold braking at all), but I didn`t really detect the typical ABS pulse in the pedal and clearly smoked an individual tire. That being said, all of the typical ABS checks look OK (No ABS light, and I know the ABS light works as an early problem has me use a wiring harness that was missing pin 20 at the c101 and that lit the ABS light up).

Long story short, I have suspicion that the ABS system is not working appropriately despite the fact that I don`t have the ABS warning light. Is there any particular checks I can do or should I just chalk it up to my craptacular driving at that moment?

#2

Your ABS isn’t working. The idea that some other cause allowed your wheel to lock up is very unlikely. I wouldn’t spend time “testing.” Sure, a different cause isn’t impossible, but I’d go ahead and assume that the problem is the ABS system.

Get your ABS light working. You need that thing working in order to tell you about a sensor or computer failure. Once the ABS light is functional, if it’s on, check your sensors. There’s an easy protocol here for identifying which sensor is the problem. Sensors don’t normally fail because they have no moving parts. It’s the wire to the sensor that fails. Computers sometimes fail. There’s a thread here from last year re. my ABS computer shorting against it’s enclosure. It was fine once I pulled the enclosure off and put a bit more insulation in between it and the circuit board.

Once the ABS light is functional, but instead it remains off, then swap out your hydraulic pump. I have a spare that I’d be happy to send you for a bit cheaper than whatever they are going for on ebay these days. First swap out the ABS pump modules, and if that doesn’t work, swap out the pump itself.

Torch the shit out of the brake line connections prior to fucking them up with a wrench. PRIOR, not after.

#3

See, that’s the part that has me scratching my head…The ABS light does appear to be functioning as it should. Comes on in position 1 on the key, turns off when the car is started. If I pull the ABS relay and start the car, the light comes on. Which is where I am wondering if there is a fault in the ABS pump (or the ABS ecu) where everything seems “normal” as far as the electrical checks are concerned but aren`t functioning properly.

Should clarify one point in my first post; I am back to using a harness that is supplying power to the ABS system. I had a fuel injector saga when I swapped my motor that had me chasing all sorts of things (including, mostly my tail). That whole ordeal certainly taught me lessons in humility with this car, so I am not really trusting “this is what it seems like” at this point!

#4

Swapped to a new (to me) ABS pump and that appears to have solved it; was at least able clearly engage ABS on a quick backroad drive in the rain. Have a couple of days up at VIR North in a couple of weeks to be able to better test it.

Also, thanks much for the tip on the lines! I torched and PB blasted them each day and had no issues with them. Very thankful for that as I really wasn’t interested in running new lines.