The heater bypass tube allows a small amount of coolant to circulate throughout your car engine when the thermostat is closed. It bypasses the thermostat, hence the name. Some engines are equipped with bypass hoses, while others have a bypass passage that forms a part of the cooling jacket in the engine. This is really just terminology – the effect is the same. The bypass tube prevents excessive pressure from being built up within the system, delivers a bit of heat when the engine is started, and allows for even cooling from the point of startup. When the thermostat opens up coolant flow in your car, the engine begins to cool. The car thermostat closes a bit and increases coolant flow through the heater core and the bypass hose.
Heater bypass tube replacement is not part of your vehicle’s routine maintenance, so your mechanic will not check it when doing an oil change or checking your fluid levels. | Cooling problems can be devastating to your car’s engine. | Don’t assume that the problem is the bypass tube – it could be the thermometer, the radiator, or another faulty component in the car cooling system. | If you have pets, keep them away from leaked coolant – it is highly toxic. If a radiator/cooling system hose bursts or leaks, the engine will not get the proper amount of coolant and will overheat, possibly causing severe damage. The hoses are made of rubber, so It is common for them to crack and weaken over time and because of the high temperature in the engine compartment.
The vehicle’s hood is opened and coolant is drained | The two heater lines are disconnected from the heater core | The new heater bypass tube is installed | The coolant is refilled and the vehicle is started | The repair is verified and the heater bypass tube tested for leaks | Pressure check cooling system for leaks. | Remove and replace the hose that is leaking or blown. | Fill radiator with the proper mixture of 50/50 coolant. | Bleed the cooling system. | Re-check for any leaks.
Problems with the heater bypass is not something you should try to diagnose or fix on your own. This is a diagnosis and repair issue that is best left to one of our expert mechanics. It is a good idea to replace the hoses every 5 years or 40,000 miles. If you see coolant (red, yellow or green fluid) on your driveway get the car inspected for leaks. If you suspect a leak, do not delay repair. Driving with leaking hoses can cause severe damage to the engine.
If there is a problem in your cooling system, you could end up with an overheated engine, and the repairs could be extremely expensive. Have one of our expert mechanics determine if the problem is with the bypass tube and replace it if necessary. . vi Power Steering Pressure Hose Replacement What is the power steering pressure hose and how does it work? The power steering pressure hose transfers the high-pressure hydraulic output of the power steering pump to either a steering gear box or steering rack and pinion unit to create the power assist that you rely on when you turn the steering wheel. The pressure hose is only used in cars with a power steering pump and reservoir, so if you have a newer car you may have electric power steering instead. The pressure hose is relatively large in diameter in order to withstand high hydraulic pressure, flex as the engine moves and vibrates, and also withstand engine heat, accidental cuts, and abrasion. When to the consider replacing the power steering pressure hose: Groaning, whirring noise or difficulty steering. Noise, or difficulty turning the steering wheel, may reflect a low power steering fluid level, which could be due to a leak in a pressure hose, or a leak elsewhere in the power steering system. Although a leak in the pressure hose is a possible cause of a low fluid level, a mechanic will consider all other possible causes, too. Visible fluid leaks. There are usually steel ferrules clamped onto each end of the rubber pressure hose. These ferrules are common leak points. If there is seepage from these ferrules, the pressure hose should be replaced. Hose damage. If the hose has significant physical damage, such as cuts, abrasions, cracks, or heat damage, the hose should be replaced to avoid sudden hose failure. Contaminated fluid. If rubber particles are found in the power steering fluid or reservoir, it means the interior of either the pressure hose or the return hose is deteriorating. All rubber hoses should be replaced and the system flushed. An in-line, aftermarket fluid filter might be required. Hose age. Both the pressure and return hoses are rubber-based products with a limited service life. If the vehicle is more than 10 years old, and power steering components are being replaced, all the rubber hoses should be replaced during that service. How do mechanics replace the power steering pressure hose? The under hood routing of the power steering pressure hose varies greatly between car models. The repair procedure ranges from simple to quite involved. The basic steps are: Raise car as needed and support with steel safety stands. Unthread the pressure hose tube nuts, or banjo-style bolts, at each end of the pressure hose. Remove pressure hose and inspect interior hose lining for separation, if visible. Install a new hose, using a new sealing washer or O-ring seals as applicable, and paying particular attention to the required original equipment manufacturers (OEM) torque value for the tube nuts or banjo bolts. Replace rubber return hose, if required, and with the authorization of the customer. Once the system is fully sealed again, bleed or flush power steering system as required to remove all air and contaminants. Finally, the engine is run, the car is test driven, and leaks are checked for at all connections. Is it safe to drive with a power steering pressure hose problem? No. The fluid in the power steering pressure hose is under very high pressure and flammable. A leak that sprays fluid into a hot engine part, such as the exhaust manifold, can cause a fire. Leaks that cause significant fluid loss can cause difficulty in steering and, if a leak causes the fluid level in the reservoir to drop too low, it can cause damage to the power steering pump too, necessitating the installation of not only a new hose but a new pump. When replacing the power steering pressure hose keep in mind: When the power steering hoses are replaced, the entire power steering system should be inspected. Use only OEM specified power steering fluid in your power steering system. If the pressure hose has deteriorated from the inside, the rubber return hose should be replaced as well and the system should be flushed. A mechanic might recommend the installation of an in-line filter to capture all debris. Tube nuts and banjo bolts used to seal pressure hoses have OEM-specified torque values. Mechanics will use a calibrated torque wrench to tighten the connections. Complete removal of air from the system can occasionally take some time, even after the normal bleeding procedure. During this time some mild noise may be heard when turning the steering wheel. If it persists more than a day or so, the system should be rechecked. . vii Radiator Hose Repair What is the Radiator Hose all about? Radiator/cooling system hoses are an important part of your car’s cooling system, which is designed to keep the engine from overheating. When your car’s engine is running it creates heat. The radiator/cooling system hoses carry coolant through the radiator and back through the engine to keep it operating at an optimal temperature. There are mulitple hoses in a given system. An upper hose connects the top of the radiator to the top of the engine. A lower hose connects the bottom of the radiator to the water pump of the engine, which keeps coolant flowing through the system. It is important to replace worn or leaking hoses as preventative maintenance to prevent future failure of these hoses where they may burst, causing engine overheating.
