Home / Products / Brake, Fuel & Power Steering
Brake, Fuel & Power Steering Hoses
Three systems that share nothing
They sit within a few feet of each other under the same vehicle and they have almost no requirements in common. Brake, fuel and power steering hose each answer to a different standard, a different pressure and a different fluid, and the fastest way to a comeback is treating any of them as interchangeable.
The Common Mistake
Fuel hose is not brake hose is not steering hose
Brake hose runs at very high pressure with a fluid that attacks the wrong rubber, and it is the only one on this page where a failure means the vehicle does not stop. It carries a marking that says what standard it meets, and that marking is not decoration.
Fuel hose is the opposite problem. Pressure is comparatively low, but what runs through it has changed. Ethanol blended gasoline attacks compounds that handled straight fuel for decades, which is why perfectly good looking hose on an older vehicle starts weeping without anybody touching it. A fuel injection system also runs at many times the pressure of a carburetor, so hose that suits one will fail on the other.
Power steering splits again. The pressure line from the pump to the rack is a high pressure assembly that runs hot. The return line is low pressure and a different hose entirely. Putting return hose on the pressure side fails quickly and messily, and it is one of the more common things that comes back through this door.
Where the original assembly is discontinued and has to be rebuilt from the old part, that work is covered on OEM hose assembly replacement.
Brake Line Flares
The two flares that ruin each other
Hard brake line is sealed by the shape formed on the end of the tube. There are two in common use, they look similar in the hand, and mating one to the other produces a joint that feels tight and leaks under pedal pressure.
Double flare, 45 degree
The tube end is folded back on itself so the sealing face is two layers of wall thick, then formed to a 45 degree cone. The doubled wall is what stops it splitting under pedal pressure, and it is why a single flare is never acceptable on a brake line.
- Seat angle
- 45 degree cone
- Wall at the seal
- Doubled, folded back on itself
- Usually found on
- Domestic vehicles and older imports
- Tooling
- Two stage die, an adapter then the finish
They do not interchange and they do not tell you so. A double flare pulled into a bubble flare seat contacts on a narrow ring instead of across the face. It tightens, it feels right, and it weeps under the pressure a hard brake application produces. Identify what came off the car before forming anything, and if you are unsure, bring the old line to the counter.
By System
What each line actually needs
DOT rated, and it says so
Flexible brake hose carries a marking identifying the standard it was built to, because brake hose is regulated rather than merely specified. Hard line is formed and flared to suit the vehicle. Clutch hydraulics use the same family of components.
- Pressure
- Very high, intermittent
- Fluid
- Glycol or silicone brake fluid
- Marking
- DOT and standard reference
Match the system, not the diameter
Carbureted systems run low pressure, fuel injection runs many times higher, and in-tank submersible lines are different again. Ethanol resistance matters on anything filled at a modern pump, including older vehicles that never saw it when new.
- Pressure
- Low on carb, high on EFI
- Fluid
- Gasoline, diesel, ethanol blends
- Watch for
- Submersible versus external
Two lines, two hoses
The pressure line from pump to rack is a high pressure assembly and runs hot. The return line is low pressure with a larger bore. They are not the same hose, they are not the same fitting, and swapping them fails fast.
- Pressure side
- High pressure, hot
- Return side
- Low pressure, larger bore
- Common failure
- Return hose used on pressure
Buying It
Cut, formed and flared at the counter
Hard line copied from the old one
Bring the original and it gets bent and flared to match, including lines the manufacturer stopped producing years ago. Steel, coated steel and copper nickel, with the flare formed to suit the seat rather than to suit our tooling.
This is regular work here, and one customer review describes exactly it, brake tubes copied after Nissan stopped making them.
Fuel and steering assemblies
Fuel line by the foot in compounds that suit the pressure and the blend, and power steering assemblies built to length with the correct end at each side. Both are counter jobs and both are usually finished the same visit.
Fabrication from a sample sits on custom hose fabrication, and the crimping side on hydraulic hose crimping.
Before You Buy
Common questions
No, and it is worth being blunt about it. Brake systems run at pressures fuel hose was never built for, brake fluid attacks compounds that handle gasoline without trouble, and brake hose is regulated and marked accordingly. This is the one substitution on the whole site that could put somebody in a hedge.
Look at the end of the tube. A double flare comes to a cone with a visible folded lip inside it. A bubble flare is a rounded bulge with no cone. In the hand they are easy to confuse, particularly on a dirty line, which is why bringing the old piece in beats guessing. Mating one to the other seals well enough to fool you and then weeps under pressure.
Almost certainly the fuel rather than the hose. Ethanol blended gasoline attacks rubber compounds that coped with straight fuel for decades, so hose specified when the vehicle was new can start swelling and weeping without anything else changing. The answer is a compound rated for the blend that comes out of the pump today.
No. Injection systems run at many times the pressure of a carburetor, and low pressure hose on a high pressure line will balloon and then let go, usually in an engine bay. Tell us whether the system is carbureted or injected and whether the line is inside the tank, and the right hose follows from that.
No. The pressure line from the pump is a high pressure assembly running hot, and the return line is low pressure with a larger bore. Return hose on the pressure side fails quickly and empties the system across the engine bay. If you are replacing one, tell us which side it came from.
We supply and build from correctly rated components and we will tell you plainly what they are. What we cannot do is certify an installation on a vehicle, and if your application needs that, it has to come from whoever is entitled to issue it. Bring the old part, tell us the vehicle, and we will be clear about what we can and cannot supply. Ask at either counter or through the contact page.
Get It Matched
Bring the line you cut off
Flare shape, thread, bore and which system it served all come off the old piece in under a minute. Walk into either counter, no appointment needed.