Brake hoses play a critical role in ensuring the safe operation of a vehicle. They connect the brake calipers to the brake lines and allow the brake fluid to flow between them. However, like any other component, brake hoses can wear out over time and become prone to failure. A bad brake hose can result in poor braking performance, loss of control, and even accidents. Therefore, it is essential to be aware of the signs of a bad brake hose and take immediate action to address the issue.
Bad brake hose symptoms
There are only a handful of symptoms of a bad or failing brake hose; they are all very similar or caused by a similar issue with the hose. They include:
- Seized brakes – Seized brakes indicate there could be a blockage in the hose, sometimes from the hose itself collapsing in on itself. This stops the brake fluid from returning through the hose when the brake pedal effort is reduced.
- The brake pedal feels different – The brake pedal could feel spongy due to a minor fluid leak from the hose. It could also feel normal when driving and pressing the brakes until you are a few miles into your journey, and then the brake pedal becomes stiff; this indicates the brakes may be seized due to a brake hose problem.
- Brake fluid – A puddle of brake fluid on the floor or seeing brake fluid dripping down the wheels could indicate a brake hose has burst. The car will be undrivable, and the brake pedal should drop straight to the floor if pressed, followed by more fluid on the floor.
- Visual issues – Discolored brake rotors with a blue tint indicate they have overheated. This can mean the brakes may have stuck on at some point because of a faulty brake hose.
The issue with thinking you have a bad brake hose without physically inspecting the hose and carrying out some tests is that all of the problems above are almost identical to those with brake calipers and wheel cylinders. So, if you suspect you have an issue, you must inspect the brakes to determine the correct problematic component.
How to diagnose a bad brake hose
Correctly diagnosing a bad brake hose requires inspecting the hoses and potentially removing the hose from the caliper. The car will need to be jacked up and the wheel removed so you can get a look at the hose; the problems you are looking for are:
- Cracks – There should be no visible cracks or splits in the rubber part of the hose. There is a liner constructed of a fabric that you might see exposed in the cracks, which means the cracks are too deep, and the hose must be replaced.
- Bulges – Check for any bulges or bubbles starting to appear. A bulge just means the hose internals have deteriorated and the only thing holding the fluid in, is the liner which is very thin. Bulges are especially dangerous because the pressure applied when pressing the brake pedal means the hose can burst.
- Connections – Inspect the unions (connectors) and where the hose crimped to its connector is not heavily rusted and still in good condition. Although this doesn’t mean the hose has failed, it could be a sign of something to come and should be replaced as a precautionary measure.
- Leaks -The most obvious but any signs of leaks through splits in the hose or around the metal union connections, and the hose needs replacing. The hose may need to be removed from the caliper to check why the leak is not a problem with the caliper.
- Collapsed hose – A collapsed hose is not visible by eye but straight forward to diagnose; it means there is blockage usually created by the hose collapsing. Diagnosing requires removing the hose from the caliper and having someone slowly apply pressure to the brake pedal; if no or very little brake fluid comes out of the hose, it is likely the hose has collapsed. To 100% confirm, remove the hose from the brake pipe and then carry out the same test; brake fluid should come out of the brake pipe at a standard rate. If it doesn’t, the problem is likely with the master cylinder or brake pipe. Remember, if you undo or remove a brake hose, the brakes will require bleeding afterward!
These are all immediate red flags; they don’t all mean the hose has failed yet but do mean the hose needs replacing regardless.
Can a bad brake hose cause the caliper to stick?
A bad brake caliper hose can cause the caliper to stick, especially if they have collapsed. The caliper sticks because the fluid cannot return when brake pressure is applied. This is more noticeable once the brakes get hot because the brakes are constantly applied, and the temperature rises. The rubber hose expands, and blockage worsens, causing the brake caliper to stick in the on position and the brakes to seize; the tires may even start to skid down.
Once the brakes cool down enough, the wheel will freely rotate, and you can drive until the brakes get hot again. The bad news is that every time you drive and the brakes seize on, you are causing more damage to the caliper, brake rotors, and pads meaning more items will need replacing.
Can you drive with a bad brake hose?
It depends on the situation; for example, if you’ve been advised the brake hoses are perishing and could do with replacing, you could drive and probably for quite some time without any issue. Still, you’ve been advised that they need to be replaced, so do this as soon as possible.
But, the problem is if the cracking on the hose is severe enough, the hose could burst at any time, so you shouldn’t drive. If the hoses leak fluid, you must not drive under any circumstances; every time you press the brake pedal, more brake fluid will leak, and the car will fail to stop.
How often should you replace brake hoses?
Brake hoses don’t come with a specific life span in that they don’t need to be replaced every so many year for no reason. As a precaution, they only need to be replaced when a problem or cracking starts appearing on the hoses. For this reason, you can expect them to start cracking and potentially be advised to be replaced after approximately four years.
Brake hoses are usually very briefly inspected by a mechanic in a vehicle service, who may advise they are replaced, or a proper brake inspection is carried out.
The two stand-out signs of a bad brake hose are fluid dripping down the wheel or a stiff pedal a few miles into a journey. It is essential not to assume the hose is at fault and to have the brake hoses inspected. All the signs and symptoms are very similar to a faulty brake caliper.
The only way to be sure a brake hose is the cause of your problems is to take the wheel off and physically inspect the brake hoses properly. Once a brake hose is changed, the brake fluid will require a full flush or bleeding at a minimum after!