Driving with an ABS Fault light or have coach towed
 

Hi,

My Workhorse UFO is booked in to Cummins to diagnose an issue with the brake system.

I am getting the below messages and the ABS light is on.

Check ABS. ABS Comms Failure. No CCM ABS Comm.

Alan at Brazels reckoned it should be towed as it may be the HCU but the Cummins Foreman said to drive it in the storage lot to check the brakes and if ok to drive it to Cummins, it just means ABS may be disabled. The journey is 38 miles.

What do folks think?

If the only symptom is the light I'd probably drive it but I have also done plenty of dumb things over the course of my life :D

This is one of those things that only you can decide what you're comfortable with doing.

However it seems to me that the Cummins guy the right answer. Find someplace SAFE in the storage lot (lots and lots of stopping room) and test the brakes, if they work as they should take it to the shop so that they can work on the ABS.

Drive it! Been driving mine for a year with ATC light and intermittent ABS LIGHTS. No biggy...brakes will work fine.

Surely y’all are old enough to remember when vehicles didn’t have abs systems...

I'd do a brake check in the parking lot and assuming it's okay I'd drive it.

Agree with this ^

I drove old buses decades ago before ABS was common --or for that matter, as Md11fpilot has said, our cars back in the 60s didn't have ABS-- and just had to make due with how we executed an emergency stop. We're pampered nowadays with ABS but back in the day, we had to pump the brakes manually in an emergency or stab-brake with air brakes.

Although I like Alan and continue to recommend Brazel's, I think he/they were doing a CYA.

I think what some here are missing is that the OP has a WCC UFO gas pusher. It has a very complicated WABCO brake system and a parking brake that is unique to that chassis, albeit similar to the one used on thousands of school buses.

If Brazel is recommending it be towed, I'd follow that advice in hopes of avoiding doing damage by driving it.


To the OP:
You MUST follow a specific procedure to tow a UFO, and many wrecker drivers have no clue how to disable the parking brake. Look in the stickys at the top of the WORKHORSE forum in the "important discussions" and find the procedure that MUST be followed to tow a UFO.

found it: https://www.irv2.com/forums/f22/relea...sis-58737.html

Drive it. The Antilock Braking System is designed to be Fail Safe. A complete failure of the system will not disable the brakes in any way.

Failure of the ABS will in a panic braking situation allow you to potentially lock the wheels which could cause the lose of steering control during the event, particularly on wet or slick road surfaces, and the total braking distance may also increase.

Oh, okay. I don't know that much about the UFOs. Does it matter pertaining to the brake system whether it is gas or diesel? My immediate thought was that the OP has a diesel as he referred to taking it Cummins. The gas-powered ones are on a Workhorse, correct? Are the diesels on a Freightliner Custom Chassis? Do both have the same brake system?

Thanks all,

I spoke again with Alan from Brazels, he explained why it to be towed. He said that if the master cylinder looses pressure tgw brakes will go out.

He is emailing me info to give to Cummins.

Not a mechanic but, you should still have brakes just not the abs part. I don’t know of anyone that has activated their abs in a MH.

Thanks all,

I am going to do as Alan recommended and have the coach towed.

Sure, but nothing in those ABS messages indicates a problem with the master cylinder or any brake hydraulics. Those message pertain to the ABS computer & communications and their only function is to prevent skids if you, the driver, jams the brakes hard enough to lock up the wheels. ABS applies the brakes selectively to do that, but doesn't interfere or stop normal braking.


My guess is that you heard a lawyer talking rather than a mechanic. Every business has to CYA these days.

Hi Gary,

I for sure understand what you say about CYA.

I am also getting an ATC light, I must presume this is Auto Traction control.

WBGO built their Destination, Latitude, and Adventurer Limited models in 3 floor plans on the UFO gas pusher supplied by WCC. The same coaches were offered on diesel pusher chassis supplied by FCCC. I don't know anything about the braking systems used by FCCC, but I assume they are air brakes as opposed to the hydralic ones on the UFO.