We continue our series of articles on possible issues with your air brake system. We have two more popular problems and provide you with possible causes as well as suggestions to repair them.
The Problem: Trailer Axle Data Plates
Here are possible causes and suggestions:
According to the Department of Trade and Industry's National Regulator for Compulsory Specifications of Act 5 of 2008, which also incorporates all the requirements of the ECE R13 regulations, the following details are stated on section 4.4. of the document and read as listed below;
"Each axle on a trailer shall be provided with information applicable to the brake design, the particulars of which shall be permanently and legibly imprinted or stamped either on a data plate permanently affixed in a conspicuous position adjacent to the axle or on the plates as required by SABS ECE R13, as follows:
- The axle make and serial number;
- The brake chamber size and the brake lever length;
- The maximum tyre size; and
- Brake lining material type and grade 4.2.3 Axle data"
In addition to this information on a data plate affixed to the axle, the following information is also required:
- The load capacity of the axle: and
- The maximum rolling radius of the tyre.
Note: Although these are standard requirements in the SABS ECE R13 regulations, I have still to see any trailer axles with all of this information affixed to them.
The Problem: Truck Brake Conversions
Here are possible causes and suggestions:
A rigid truck with existing EBS brake system, cannot be converted to a truck tractor by simply installing a standard trailer control valve. Due to the incompatibility between the components, i.e. using an electrical brake system (EBS) with a normal pneumatic trailer control valve, the towing vehicle brake system will not function correctly and cannot efficiently control the trailer brake system. Also, this type of conversion is not approved by the OEM truck manufacturers.
If the truck is not fitted with an EBS brake system and is either fitted with a standard ABS brake system or is fitted with a standard brake system, then it is acceptable to install a standard trailer control valve, however, when doing this conversion it is also necessary to make sure that the hand brake valve that is fitted to the truck is a 3-port unit, (in other words one supply port and two delivery ports, not forgetting the exhaust port). The extra delivery port is necessary to meet the requirements of the SABS ECE R13 regulations and is there to operate the trailer control valve independently of the spring brakes.
Standard trucks, because they are not originally equipped for towing trailers, only need the hand brake valve to apply and release the spring brake boosters, but if converted to tow trailers the extra port on the hand brake valve is necessary to comply with the "test position" application of the regulations.
This handy tips will help you sort out your faulty air brake system. If you need professional help, JMR specialises in brake systems and parts and we uphold the highest standards in workmanship. Please contact us today for all your brake system needs.