Weird ABS problem that stumps dealer

Usually they are buried in the cab somewhere. I like to look at the wheel speed sensor connectors. Bendix are square and Wabco's are round. Those are two brands that make up 99% of the ABS manufactures over here. About 80% of trucks we work on have Bendix systems.

 

wabco is square too)))

first of all, cab mounted ABS and EBS units volvo put in cabovers only.

on conv. designed trucks, like VN ABS unit is frame mounted like on trailers. It is on right frame rail, under sleeper and power supply and j1587+J1708 wiring runs from cabin via MCFC connector.

WSS wiring, modu;ator wiring is frame mounted.

to identify unit you can use dashboard ore VTT/PTT/VCADS pro. You can read wabco unit number. It is like 446 XXX XXX x

 

bendix ABS is just rebranded Knorr Bremse, ECUs are made by Bosch

 

Pablo, you sound mad, or upset.

 

Here is picture of what the round Wabco sensor connectors that I was referring too look like. Can you show me a picture of the one you are talking about?

 

ouh.. it is just WSS.... But really Knorr/Bendix use square connectors. But really these sensors are interchangeble, and truck makers may use round ore square connectors with any system.

I wanted you not to identify WSS, but identify ABS control unit. It is in square box under sleeper.

I do not know why, but Volvo install Knorr/Bendix EBS with disk brakes, but WABCO ABS with drum brakes. They introduced ABS on F12, later on FM, NH trucks, they started with Wabco ABS C, in early 2000s they used ABS D and D+, now they use ABS-E.

Sensor I can see on picture is Wabco S+ wheel speed sensor. 16x79 mm, used on rear disk brakes and front drum brakes. On rear drum brakes short sensor is used.

about the problem... I'm sure it is rattle issue. Becouse S+ sensor in not interference sencetive like old were

 

Here is a link to a service manual for Bendix. There is picture on the front page of cab and frame mounted ECUs. Most trucks here have cab mounted units.
http://www.google.ca/url?sa=t&rct=j...sg=AFQjCNF3vfDeMW1q-35WhOYY3tpiZzsjYA&cad=rja
Here is link to a Wabco manual. Page 6 has a picture of cab and frame mounted units.
http://www.meritorwabco.com/MeritorWABCO_document/mm0112.pdf
We don't have too many trucks yet with disc air brakes. They are just starting to show up. I would be nice to be able to interchange wss between brands. The wire harnesses on the trucks here don't allow it, like I mentioned at at the start they used different connectors.

 

The shop I work at services all makes of trucks. Most trucks here use cab mounted ABS ECUs. Different models and different years the ECUs are all over the place and hard to find sometimes. That is why is it just easier to look at the sensor connectors to see what system it has so I get the right software connected to it. For many many years now Wabco has only been round connectors and Bendix square.

 

Actually most abs systems now days are bred with a T/C system, therefore they have a lot in common. For instance they may use a common p/u and a common ring. More specifically they may use an "anti-lock traction relay valve" (ie: Bendix uses an atr-6 or atr-3). Generally these valves are drive axle located but some manufactures for whatever reason uses them at all locations meaning that although most would not associate a traction control light with a steer axle, it is possible. If any one of the speed sensors (Including a steer axle sensor if equipped) either fails to report or gives a false report (In comparison to the others) you get both lights.

Most definitely.

 

Hi 4play,
Other than the obvious how do you like your Volvo with the Ishift?
I’m looking at buying one in the next couple of weeks, Iv ran a lot of Volvos in Europe and found the D12 good but troublesome and expensive when they get high mileage on them, the D16 has to be the biggest POS ever made, wouldn’t own one ever again. How is the D13 working out for you? Ishift wasn't out when I was operating Volvos back then. We mostly do End Dump work but will occasionally take the Step Deck OTR, what gearing is your rear end? I’d like to be geared low enough for End Dump but high enough to comfortably cruse at 70-75 once out of CA!?
Is there anything you would or wouldn't opt for if you were ordering a new truck to drive yourself now that you have one?