Repair kit or new custom-made hose? How to choose the right solution

You have found a leaking hydraulic line. Now the question is: do you cut out the damaged part and put a coupling in between, or do you order a complete new hose? The answer depends on four things. Check them in this order.

 

Question 1: Does the repair coupling fit your hose?

This is the determining question and at the same time the most frequently overlooked one. Our repair couplings fit factory hoses with:

  • an inner diameter of 1.8 mm or 2.0 mm
  • an outer diameter of 4.5 mm, in practice between 4.45 and 4.55 mm

You can identify this by the imprint on the hose itself: AF1.8 or DN1.8 for 1.8 mm, and AF2.0 or DN2.0 for 2.0 mm.

Is there something else written on it, or nothing at all? Then measure the outer diameter with a precision caliper. A regular tape measure or ruler is not accurate enough here. The difference between 4.5 mm and 5.0 mm is hardly visible to the naked eye, but it determines whether the coupling will hold. In our article about measuring your hose, you will find detailed measuring instructions.

Does it not fit? Then a custom-made hose is your solution. No doubt, no middle ground.

 

Question 2: Is your model on the exceptions list?

We know that for some models the repair coupling does not fit. In these cars, the factory lines deviate:

  • Saab 9-3 Convertible (1998-2003)
  • Jaguar XK8 / XKR (1997-2006)
  • Bentley Azure (1996-2003)
  • Aston Martin DB7 Volante (1997-2004)
  • Rolls Royce Corniche (2000-2002)
  • VW Golf Cabrio (1994-2002)
  • Ferrari 355 Spider (1995-1999)
  • Audi TT Roadster (1999-2006)

If your car is on this list, do not order a repair kit. For these models, we supply custom-made hoses, and for more exotic couplings, we have a special version. We prefer to mention this list beforehand rather than afterward: a return costs you time and us both money.

 

Question 3: Where exactly is the damage located?

Even if the dimensions are correct, there is a limit. The coupling can rejoin a hose as long as there is at least 19 mm of hose remaining from the metal connector. If the tear is closer to the fitting than that, there is not enough material to clamp onto.

Is the damage in the middle of the line, with space on both sides? Then the repair kit is ideal. Is the damage close to the end, or exactly where the line makes a sharp bend? Then a new hose is the better choice. A coupling at a bending point is a weak spot in the making.

 

Question 4: How many places are affected?

Check the entire line, not just where you see the oil. Lines age uniformly. If one spot is torn, the other bending points are often already hardened. A second tear within a few months is not uncommon.

  • One damage, rest feels flexible: repair kit.
  • Multiple damages, or line feels hard and brittle everywhere: custom-made hose.

Are you considering fixing it with couplings anyway? That is possible, but expect to need multiple couplings. From two or three, a new hose is usually more economical and reliable.

 

Which solution fits your situation?

A practical tip: many customers order the complete set even if they think they only need one coupling. The reason is that you often only find the second leak after the first one has been repaired and the system is back under pressure. One of our customers later wrote that he was glad to have taken the set with two couplings, because there turned out to be two holes in the end.

 

Three things to know before you start

  • The coupling is for single use only. Once it has crimped, you cannot reuse it. So measure twice before you cut.
  • You need workspace. The repair must be done on site. If the damaged line is in a place where you can barely reach it, weigh whether disassembly and a new hose is not more practical. A customer rightly noted that the coupling saves an extreme amount of work, provided the spot is accessible.
  • Expect to bleed the system. After every repair, there will be air in the system. Refill the oil and fully cycle the roof several times. In our article on refilling and bleeding, you can read how.

 

How long does the repair take?

The repair itself is not complicated. Customers regularly report that they were finished within an hour, including disassembly. Most of the time is spent getting to it, not on the coupling itself. What makes it difficult is not the action but the certainty beforehand: does it fit, and have I measured correctly.

 

Still in doubt? Send us a photo of the imprint on your hose and of the location of the damage, and we will take a look. That will cost you five minutes and prevent a wrong order. Contact us.

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