Volvo Raw Water Pump

[trapezeartist]

I have just had the raw water pump of my Volvo D1-20 rebuilt (a long story that I may recount another time). Having refitted the pump, no water was flowing and there was a new leak from the pump. I traced it to the little screw that secures the internal cam. When I tried to tighten the screw it was loose and wouldn't tighten. I've now taken it all out and it looks like the thread is stripped off the end of the screw. Maybe the mechanic who rebuilt the pump did it. Or maybe it was like that before I removed the pump, and I didn't notice.

So now I need a replacement screw (hopefully not the cam as well). Can anyone suggest a source (it's not shown on the Keypart website)? Or does anyone know the thread size so I can attempt to find a screw from somewhere (anywhere) and maybe also run a tap through the cam to clean up the thread?

Thanks.

 

[noelex]

Vyv Cox is the expert in these matters, so hopefully he will see the thread and give you some advice.
I would Drill and retap the thread for a slightly bigger bolt. The bolt only holds the cam in place and alows the cam to be changed when worn. A stainless bolt is introducing a dissimilar metal but is easy to get and should still be fine with some sealant on, which it should have anyway.

 

[vyv_cox]

Sorry, I don't know, and not knowing whether the pump is Jabsco or Johnson I couldn't even guess whether it is metric or imperial. I would take the cam to a chandlery and see what fits it. The original is brass, I think, but as John says in this situation a stainless one won't do much harm.

 

[oldsaltoz]

Also consider returning it the person who did the work on it, you just might get it done for free, or get it fixed by a pro anyway.

Good luck and fair winds.

 

[pvb]

So now I need a replacement screw (hopefully not the cam as well). Can anyone suggest a source (it's not shown on the Keypart website)?

You can buy the screw as a VP part for about a quid. Look at the online parts shop for any VP dealer - see here for example.

 

[trapezeartist]

Thanks for the advice, chaps. The problem I had was that I needed to find a solution at very short notice if I was to get the use of my boat this weekend.

My solution was:
Buy 100 M4x12 brass screws from Screwfix. Cost £2.18. (I now have 99 spares just in case it happens again, and again, and again.......)
Get a long stainless M4 screw that I happened to have in my bosun's box and saw two small slots in the end, just down to the root of the thread.
Chase the thread in the cam with the stainless screw.
Put a plain M4 nut on the brass screw to reduce it's effective length to 9mm (the original was 8mm).
Assemble with Loctite screw lock.

Phew! It worked.

 

[wotayottie]

Thanks for the advice, chaps. The problem I had was that I needed to find a solution at very short notice if I were to get the use of my boat this weekend.

My solution was:
Buy 100 M4x12 brass screws from Screwfix. Cost £2.18. (I now have 99 spares just in case it happens again, and again, and again.......)
Get a long stainless M4 screw that I happened to have in my bosun's box and saw two small slots in the end, just down to the root of the thread.
Chase the thread in the cam with the stainless screw.
Put a plain M4 nut on the brass screw to reduce it's effective length to 9mm (the original was 8mm).
Assemble with Loctite screw lock.

Phew! It worked.

It will - for a while. Its brass and the Volvo item is bronze. You will get corrosion and ultimately failure. Best replace with a Volvo one when you get chance.

Had exactly the same problem myself. Short term I replaced the cam screw with one off the cover and replaced the cover one with a stainless item until I could get the right one.

 

[vyv_cox]

I cannot speak for whichever pump manufacturer Volvo have selected, but I do know that the covers on both Johnson and Jabsco seawater pumps suffer dezincification. So while the body may(?) be bronze, the cover most definitely is not.

 

[trapezeartist]

Wottayottie, I am anticipating some dezincification and will be checking for that. I've got 99 spare screws so that should get me through for a while (as long as I didn't use too strong a grade of Loctite).

Vyv, yes, my cover plate is looking pretty pink on the inside.

 

[nigelmercier]

I cannot speak for whichever pump manufacturer Volvo have selected...

Is it possible to ID the make and model from pictures?