Helicoil type repair?

[chris-s]

Found out today that the bleed screw on the secondary fuel filter housing of our VP MD2003 has stripped the threads on the housing and been ‘bodged’ by the previous owner using plumbers tape and an o-ring but after change the filter I couldn’t get it to seal again so have removed the filter housing for repair.

The bleed screw is an m6 thread so I’m thinking of using an m6 helicoil type of thing to repair it.

Sound ok?

Chris

 

[burgundyben]

Is it a taper seat? If so, helicoil will only be successful if its really central and not wonky.

If you happen to be on Isle of Wight pop round and I'll do it for you as I have them.

 

[vyv_cox]

The exhaust studs on my Lomax are 7 mm. I have helicoiled several of them, quite successful.

 

[Boater Sam]

Found out today that the bleed screw on the secondary fuel filter housing of our VP MD2003 has stripped the threads on the housing and been ‘bodged’ by the previous owner using plumbers tape and an o-ring but after change the filter I couldn’t get it to seal again so have removed the filter housing for repair.

The bleed screw is an m6 thread so I’m thinking of using an m6 helicoil type of thing to repair it.

Sound ok?

Chris

There should be enough meat in the metal to drill out and tap larger.

 

[chris-s]

Thanks, no it’s not tapered and yes there is enough meat to go up a size, tho then I would need to find the correct sized crush washer (not difficult)

 

[Boater Sam]

There should be enough meat in the metal to drill out and tap larger.

I would rather have to buy a washer than a helicoil kit!

 

[penfold]

As long as you can use a drill press to do the drilling to ensure it's square to the sealing surface it will be fine. Helicoil is preferable to drilling and tapping for the next size up as it's stronger than a thread in the potmetal these things are made of.

 

[chris-s]

I have a drill press so that shouldn’t be a problem. Does anyone know if what looks like a small copper washer on the bleed bolt hole is supposed to come off? I’ve tried picking it off but it is not showing any sign of movement and I don’t want to damage anything with more force.

 

[vyv_cox]

I have a drill press so that shouldn’t be a problem. Does anyone know if what looks like a small copper washer on the bleed bolt hole is supposed to come off? I’ve tried picking it off but it is not showing any sign of movement and I don’t want to damage anything with more force.

View attachment 155646

Yes, it comes off.

 

[penfold]

It's just stuck down with paint or goop, a screwdriver will shift it.

 

[chris-s]

Thanks.

One final question for tonight at least, the banjo bolts had a copper and an aluminium sealing washer each, why different types and does it make and which goes where ?

 

[penfold]

Either can be used, but I'd only reuse copper after annealing, I'd bin alu washers after a use. Alternatively dowty bonded rubber seals can be reused multiple times. Makes not much odds which, although using only one kind per banjo is a good idea.

 

[ithet]

Have not read this whole thread as there is expertise that I do not have. But I have had a helicoil fitted to exactly the same type of housing on a VP2002 that had a stripped bleed screw (and a subsequent mid-channel engine failure). The job was done by the engineering company at St Peter Port, and there were no further issues.

 

[Refueler]

I am a great believer in the Helicoil. Many years ago when I used to ride Lambretta's (I had 3 of them) .... each eventually ended up with Helicoils for the spark plugs, due to the alloy heads.

I believe that they became frowned upon later ? probably because of poor amateur installs ?

 

[chris-s]

Thanks to Amazon prime, the helicoil and crush washers arrived today. Fitting that was easier than expected and so there was still time to get to the boat, put it back together and see if it will works….which it did!

Thanks for your help guys.

Chris