Getting Old Hoses Off Barbed Fuel Injectors

[Captain Obvious]

I'm working on getting the old dry-rotted cracked leaky hoses off some fuel injectors.

In the past, I've simply cut/pulled/snipped/pried the old hose off the injectors, and while that works, it's always resulted in some scratching to the barbs on the ends of the injectors. The FSM talks about grinding the hoses off and I'd like to give that a try. Problem is, grinding could destroy the small metal ferrules at the base of the hose.

So, question is... Anyone have a source for replacement ferrules?

Here's a pic of injectors with and without the hose. I used the old standby method to get that hose off (in pieces), and I'm looking for a better option. Before and after the cutting/slicing approach to hose removal:

If I destroy these ferrules, are replacements available? Note that you can see some scratching on the hose barbs from the removal process:

[Mark Maras]

 I don't know if the ferrules are available but I'm sure you've already thought about how to make them.

[Captain Obvious]

Haha!! You know me well my friend!

I'm pretty sure I could make them, but I'm also pretty sure I would just rather buy them! 

[Zed Head]

Found this - https://injector-rehab.com/product/ferrule/

 

Answer to question not asked - I had a vague memory and found its source.  It's in the FSM Engine Fuel chapter.  One of those old wood-burning tools would work too, I'd guess.

Edited May 25, 2023 by Zed Head
fond > found

[Yarb]

I made a makeshift rack and submerged the hoses in boiling water. They softened up and came off somewhat easier?

[Dave WM]

A power drill with a small drill bit will eat out the remaining rubber stuck between the ferrule and the barb, that is once you have the line gone down to that part. Just get a bit smaller than the space you are trying to clear, stick it in the rubber and apply power, it will chew up the rubber and make it easy to get out. 

[Zed Head]

Burn it like a bushing.  Burn it!  burn!  burn!

 

[Captain Obvious]

Zed Head, Thanks!  I don't remember ever seeing that soldering iron technique in the FSM. I had always remembered the recommendation to grind the ferrule off and then peel the remaining rubber. Interesting thing is... The 75 manual recommends a grinder, but after that (76 an later) recommends the soldering iron. It's not like I spent a lot of time pouring over the 75 manual, but I couldn't find any other mention of doing it that way.

Anyway I'll give that a try, and if that doesn't work, I'll try burning it like it floats.     Thanks!

 

[dutchzcarguy]

17 hours ago, Captain Obvious said:

I used the old standby method to get that hose off

CO.. What is that.. the old standby method? and.. what is the function exactly of this ferrule? and last but not least.. how are you supposed to get them ON again?

Also.. I'm glad that our euro cars not suffer from rotten rubber lines so often.. (My 280zx injectors are 44 years old and in very good condition..)

[Captain Obvious]

Well for me, the "old standby" method is using a razor knife to cut a slit into the rubber hose allowing it to be pulled off the barbs. That and a lot of swearing. The swearing is especially important when you get down to the bottom and are digging around inside the ferrule with the tip of the razor knife. But the problem with that old standby method is that no matter how much swearing is employed and despite how careful you are (I am?) with the razor, you always cut a little too deep and put cut lines into the barbs of the injectors.

Memory says I've seen pictures and instructions put out by Datsun that warn exactly  NOT to do it that way because of the inevitable damage, but that's the same old memory that says I've seen many recommendations for grinding the tubing off.

As for the purpose of the ferrule? I'm thinking it's primarily there to prevent the tubing from being inserted too far onto the barb. It might also provide some support to the end of the tubing to prevent fraying and cracking over the years, but mostly for insertion depth. And as for how to get new tubing on? The service manual says to just put a little gasoline into the end of the new tube (as lubrication) and push it on. No clamp required.

So I will try the soldering iron method for removal. Since the reinforcing threads inside the tubing are polyester, it makes a lot of sense. I have high hopes.

[Zed Head]

8 hours ago, dutchzcarguy said:

My 280zx injectors are 44 years old and in very good condition..

My 76 injector hoses looked okay on the outside but they were split on the inner diameter.  You could see the tiny radial cracks.  I smelled fuel one morning, pulled over, left the engine running and opened the hood and a tiny stream of raw gasoline shot past my head on to the sidewalk.  I had a screwdriver in the car and cranked the clamps down to get home.  The engine was cold, otherwise my car probably would have ended up like one of those in AV8's recent thread.

On replacing the hoses - I used Gates EFI hose, and gasoline to press the pieces on, but I found that the material "creeps" over time on the clamped end.  I had to retighten the hose clamps at the rail a couple of times.  If I was doing it again I'd try to find some constant tension clamps.

[Patcon]

I was thinking boiling water too. Seems like a heat gun would be too inaccurate