Moaning + pedal pulsating while turning

I have no beef with Powerstop. In fact, for the '03 using 13WL calipers, I typically recommend the Powerstop S2712 as a replacement. Powerstop remanufactures all of their calipers from scratch in Illinois and pre-tests before market, so there's virtually no reason to be concerned about getting a bogus caliper from them. Similar to Denso's reman program, Denso remans all their parts and pre-tests over at their rebuild facility in California.

 

Couple of questions there Shifty. About a month ago, I was messing around with my front ABS sensors in prep for drilling out the mounting bolt (broken-off head) for the ABS/brake line bracket that attaches to the spindle.

I removed the 10 mm bolt out of the sensor itself which didn't want to come out of its hole. Does the sensor itself just come straight out or is there a twist tab or other locking mechanism that also keeps the sensor in place. I was making sure that I can pry it straight out with a screwdriver or other pry tool but if there is a twist tab, I didn't want to break anything because of a design feature that I didn't know about. I've never been there before and I don't know that it has ever been pulled, at least to my knowledge.

Turns out, I had to abandon the stud removal project in order to finish installation of an 02 sensor and Suspension Maxx sway bar links.

My second question is are O-rings present on both the front and rear sensors? EPC only shows 0-rings for the rear sensors and a total of 2 per vehicle. Sometimes, small parts are missing on the parts diagrams for my 04 and wanted to make sure that is not the case here.


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The sensors come straight up and out. Sometimes it takes a little shimmy back and forth while lifting to get them out. That o-ring holds them in tight, pretty sure it's only one, pic below, you don't want it to look like the thread I'll link here.

That said, it should just lift out. And a couple of things are important. One, that the sensor gets reinstalled squarely in the hole. Two, that the o-ring(s) are intact and in good shape. Three, that when you look down in the hole, the tone ring teeth are covering at least 50-60% of the view hole, so the tip of the sensor can "read" them (sometimes bearing replacements lead to the tone ring being over/under-pressed). Lastly, there's no garbage buildup on the magnetic tip of the sensor or the tone ring. One should ideally check these things any time the sensors are out, and note not to put the tip of the sensor into sand or dirt, where it can pick up tiny metal particles.

This thread talks about the o-ring experiences @Hi06silver dealt with, with ABS pulsing on/off due to poorly centered installation, caused by an exhausted o-ring, he pictures in the 1st reply: https://www.tundras.com/threads/slow-speed-abs-activation-fixed.131442/

While potentially not applicable to your 2004, in the '05+ trucks, the speedo gets its rotational information from the ABS sensors, I believe from the rear sensor(s), not sure if a specific one or both - I think @des2mtn knows that one, EPC shows both rears as 'speed sensor' so possibly both. Here's where the o-ring is located on the rears, since I'm not seeing that in hi06's thread. I assume the fronts have similar, but their wiring is much longer and integrated to the sensor, All four sensors use different part numbers for my '06.

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Not sure if it helps, but here's the diagram for my '06 AC. I'm boxing the part index number (which is also the first 5 digits of the part number). Clearly you can see they offer an o-ring for the rears, but not the fronts. The front sensor *DOES* have an o-ring though, as shown below. Also worth noting, the front sensors have a pointed tip, the rears have two bars in the shape of an equals == sign on a snub tip.

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On the '04 (possibly 05-06 too), the Speedometer and Odometer gets its reading off at least one of the speed sensors on the rear axle. If you have a short or one that's disconnected, your speedometer will still work, but your ABS will not. If both rear speed sensors are shorted/disconnected, you'll have no speedometer, odometer or ABS.

Your ECU/ govenor gets the rest of the stuff it needs off the vehicle speed sensor that reads the transmission/ transfer case output.

Pretty sure all the front speed sensors do is send signals for the ABS, nothing else.