Releasing the Parking Brake prior to Towing a UFO Chassis

[DriVer]

Releasing the Parking Brake prior to Towing a UFO Chassis

Workhorse vehicles with “F” in the sixth digit of the chassis VIN are a UFO/R26 rear engine chassis. This vehicle can be powered by either a gas or diesel engine. The following steps are necessary to properly tow this vehicle.

1) Secure the front wheels or front axle to the tow truck lift. Lift the front of the vehicle up, however do not lift so much that the back of the vehicle will be at an angle that will damage components such as the oil pan of the Allison Transmission.

2) The parking brake must be released at the Spring Apply Hydraulic Release/SAHR canister. The SAHR canister is located in front of the rear axle mounted inside the left side/driver side frame rail.


SAHR Canister

Take two 15mm open end wrenches and loosen the jam nut on the cable that is threaded into to the SAHR canister. Then take the 8mmopen end wrench and at the back of the threaded cable place the wrench on the flat of the threaded rod and begin to back the threaded rod all the way out of the SAHR canister. Fully removing the threaded rod from the SAHR canister will cause the parking brake to release. Do not lose or damage the jam nut. Place loose jam nut in a plastic bag and leave it in the drivers area of the vehicle. Secure cable with zip tie to keep it from being damaged.

3) Then proceed to the short prop shaft and remove the cap bolts and straps. Then remove the prop shaft from the Allison transmission and the Bosch parking brake drum. Do not lose or damage the cap bolts, straps, or prop shaft.

4) When dropping off at servicing dealer chock wheels so the unit will not move because of disconnected parking brake. Let servicing dealer know what has been disconnected and that unit will roll if wheel chocks are removed. If no wheel chocks are available then the cable will have to be reinstalled in to the SAHR Canister. The threaded rod has a notch in it that looks like missing threads. Install jam nut back on to the threaded rod before re-installing the rod into the SAHR canister. Reinstall the threaded rod to the notch and tighten the jam nut.


Courtesy: Redlands RV Performance Center

[cj5 jeeper]

Thank You! Thank You! Thank You! Hope I never need it, but if something ever happens this could be a lifesaver. In the event of a breakdown having this info on hand could save a lot of time and hassle. I made three copys, one for the folder at home, and two for the binder in the motorhome. If we ever meet I owe you a drink.

[gbs2320]

Thanks Driver. Your the GREATEST! This would make a good sticky, IMHO. Greg

[coachmanrvr]

I just found this...what this would have saved me!

When we had to have ours towed for the FCA blowout it was a few hours down the road. The only way we and the tow truck driver could figure out how to tow was to leave the key on. This worried me greatly about the battery going dead towing down the road.

We removed the propeller shaft, uplugged the daytime running lights, and tied the house batteries to the engine battery with jumper wires. This would have been much easier!!!

Thanks Driver.

[Lash]

I have now had first hand experience with the UFO towing procedure in regards to the SAHR. Driver put out a comprehensive post on this subject over a year ago. This procedure was not used by a tow service who towed our MH and it ended up costing me 7 travel days.

In April, I had a Wabco Hydraulic Accumulator fail and I had to be towed some 80 miles to Houston. I made the mistake of not checking how the tow operator got the unit ready for tow after he had discussed the procedure with Workhorse on the phone. I had put over 5000 miles on the unit prior to a trip in July with no further issues.

In July, we were transiting from Las Cruces NM on the way to California. About one hour out of Las Cruces, a number of alarms came on in regards to the Hydraulic Brake system as well as verbage on the LCD display on the dash. I tried the brakes and all worked fine so I decided to continue on to Santa Fe NM as Hal Burns Trucking was available to look at the problem. Took some 3 days of intermittent troubleshooting but the culprit turned out to be the wire cable from the SAHR started to unwind causing the adjustments to go out of whack and create the alarm situations. This damage to the SAHR cable most likely occurred in April as a result of the MH tow.

Of course it was late on Friday and the parts did not get to Santa Fe until the following Tuesday morning. Repairs were made and adjustments made on linkage and we continued our trip.

Best part of all this was some great Mexican food as well as finding a super WH service dealer.

Will also confess that I had copied this thread when Driver sent it out, but the brain cells have caved in some and I forgot I had it. Shame on me.

Regards

[DriVer]

... √

[BigGeorge]

I'm sympathetic to forgetting emergency procedures in the heat of the moment. I printed Driver's brake disabling instructions and stuck them under the plastic front cover of my chassis & engine binder sitting in the cabinet above the steering wheel. When and if my time comes and I pull out the manual, I'll be looking at his instructions. Some days later he gets a bottle of wine or other favorite libation in the mail.

Just to ensure Driver never gets a thank you gift from me I'm going out to buy the wrenches he specified and a zip strip all ready for the DAY. When you're fully, fully prepared, it doesn't happen.

[gbs2320]

"Best part of all this was some great Mexican food as well as finding a super WH service dealer."

Yes,Hal Burns truck center in Santa Fe did great work for me also -- on my fan clutch replacement. I keep a copy of the emergency brake towing release procedure in the rig also.

[gresults]

Well between the two of us we got the unit towed to the Wrecker storage lot and hopefully somebody will be open Friday that can work on workhorse.

If not might be Monday before we find anyone and get heading back to Houston.