The defect
THE DUAL DOUBLE CHECK VALVE MAY NOT RELEASE THE PROPER AIR VOLUME TO THE BRAKE SYSTEM, CAUSING A SLIGHT TIMING DELAY BETWEEN THE TRACTOR AND THE TRAILER BRAKE SYSTEM. CONSEQUENCES OF DEFECT: IF THE BRAKES ARE SUDDENLY APPLIED, THE TRAILER COULD JACKKNIFE WITHOUT WARNING TO THE OPERATOR, WHICH COULD RESULT IN A VEHICLE CRASH.
The remedy
INSTALL TWO NEW SLEEVES IN THE DUAL DOUBLE CHECK VALVE WHICH WILL INCREASE AIR FLOW.
NHTSA's own wording · initiated by MFR
Vehicles covered
| Model | Model years |
|---|---|
| Mack MH | 1982, 1983, 1984, 1985 |
Components: SERVICE BRAKES, AIR
Model years in this recall
NHTSA complaints and the number of recall campaigns for each model year this recall covers.
| Model | Year | Complaints | Recalls |
|---|---|---|---|
| Mack MH | 1982 | 0 | 7 |
| Mack MH | 1983 | 0 | 8 |
| Mack MH | 1984 | 0 | 9 |
| Mack MH | 1985 | 0 | 5 |
Other service brakes, air recalls in 1985
11 of the 173 recall campaigns reported to NHTSA in 1985 concerned the service brakes, air; MACK TRUCKS, INCORPORATED filed 245 campaigns in all.
| 85V171000 26 Dec 1985 | BLUE BIRD BODY COMPANY |
| 85V170000 23 Dec 1985 | OSHKOSH TRUCK CORPORATION |
| 85V161000 3 Dec 1985 | FREIGHTLINER CORP. |
| 85V150000 19 Nov 1985 | OSHKOSH TRUCK CORPORATION |
| 85V148000 15 Nov 1985 | TRANSPORTATION MFG. CORP. |
| 85V085000 2 Jul 1985 | GENERAL MOTORS CORP. |
| 85V074000 6 Jun 1985 | VOLVO GM HEAVY TRUCK CORP |
| 85V063000 14 May 1985 | NEOPLAN USA CORP. |
NHTSA recalls (public domain) · all recalls of 1985