Tech Tip #8 – Brake Hose Failure

Owners should be aware of a potentially serious brake system failure. The problem occurs when a main brake pressure hose section from the ABS/ASC/DSC hydraulic control unit ruptures and causes the brake system to loose hydraulic pressure.

Due to age and thermal exposure to engine exhaust manifold heat this particular brake hose section slowly deteriorates. Under braking pressure, at the point when most needed, the hose failure occurs. We at Bavarian Machine Specialties have seen a number of these failures and have also identified many potential problems during our thorough routine maintenance program. The problem is most likely to occur on cars older than 7 years with more than 60,000 miles. A recommended inspection of these hoses is strongly advised and can be easily accomplished.

The hoses are located along the passenger side fenderwell (see picture) and can be assessed without removal of any components. The parts and labor costs to replace these hoses is fairly inexpensive and well worth the assurance that the brakes will not fail. The brake hydraulic system must be re-bled after the hoses are replaced and in addition the cycling of the ABS hydraulic unit solenoids must be carried out. As an added level of protection, when the hoses are replaced, we at Bavarian Machine Specialties install an outer heat barrier sleeve to protect the new hoses and prevent the problem from occurring again.