help with Volvo 'radiator cap' coming away whilst we are on holiday!! MD2030 C

[TactilePaul]

this 'achilies heel' is causing trouble again, it has come apart where the red line is, first question, can we strap it, pug it up with a good PU mastic and use it for the short term without any other worry than having to regularly pour coolant into tank!?,
I know that this is not designed for anything other than a cap, I feel the pipes and brass block cause vibration issues, I wonder if anyone has changed this to some solid plumbing and a safety pressure vent, as that's how i feel it should be!!

any other help regarding long or short term soloutions, parts , avainlibility etc hugely appreciated. We are in Poole, were hoping to leave today, but not looking good.
Thanks

 

[veshengro]

A wild guess from me, but if it is purely a Radiator cap with no other 'Boaty' function, would a visit to a lorry breaking scrapyard find you a spare? Do Marine Volvo's have the same size radiator caps as their shoreside road Artic cousins?
If the usual Swindlery prices apply to Volvo spares, even a longish journey to a lorry scrapyard may pay off.

 

[TactilePaul]

A wild guess from me, but if it is purely a Radiator cap with no other 'Boaty' function, would a visit to a lorry breaking scrapyard find you a spare? Do Marine Volvo's have the same size radiator caps as their shoreside road Artic cousins?
If the usual Swindlery prices apply to Volvo spares, even a longish journey to a lorry scrapyard may pay off.

good call, but the red line is not anywhere near the cap!!

 

[rogerthebodger]

Any vehicle radiator supply company should be able help

I had an issue with my heat exchanger pressure cap and my local radiator company helped me out with a replacement fitting

radiator neck repair kit - Google Suche

 

[Boater Sam]

Its been bodged, there should not be the brass gubbings on the cap.
Its broken off the heat exchanger, expensive. Epoxy putty may save you short term

 

[PCUK]

First get rid of the junk attached to the rad' cap, that will prevent future problems. I'm now thinking about these low temperature welding rods that work with a blow lamp. One if these may provide a permanent solution. I have no experience of these but they look promising.

 

[Mister E]

There is something wrong with the set up. If that is a vent pipe why is it not connected to the small fitting copper pipe on the radiator?
The cap looks like an old Series Land Rover or Mini any BL vehicle from the 80s or before.

You need to remove the pipe going into the cap and tee it into a suitable hose, there may be a pipe you could use near the thermostat housing or the back of the cylinder head.

 

[Martin_J]

If the filler neck is coming away from the heat exchange housing, I mentioned a solution in a previous thread and the poster there did get the Thermex part... It was some years ago and the Thermex website wasn't great then but they do still still show a bolt on aluminium filler neck..

Thermex Filler Necks and Pressure Caps




This was the previous thread where the fitting of the above part was described.

VP 2040 c2001 filler cap neck atop heat exchanger on the move!

 

[Just_sayin']

Paul, isn’t the problem that the filler neck is detaching from the heat exchanger?

If so, see if you can change the thread title … I don’t know how long you get to do so.

Your red line is perfectly clear to you but to others I think it’s merely underlining the cap.

 

[ChromeDome]

On mine the contraption added to the cap goes to an expansion tank.

Out of two engines this is fitted to one feeding the domestic water heater only, presumably to manage the extra amount of cooling plus the potential amount of air to be trapped in the extended circuit.

 

[Mister E]

You can get a cap to blank of the radiator filler.
Then you fit the pipe from the heat exchanger to the tube on the radiator.

If the fitting on the radiator goes to an expansion bottle then this is plain wrong and should be removed and the proper tube used.

Then the filler neck can be soldered back on or clean it up and use chemical metal from a motor factors.

 

[TactilePaul]

Paul, isn’t the problem that the filler neck is detaching from the heat exchanger?

If so, see if you can change the thread title … I don’t know how long you get to do so.

Your red line is perfectly clear to you but to others I think it’s merely underlining the cap.

Yes. Your correct. The problem is that it’s called different things , the original manual calls it the expansion vessel , I’ve seen it called the heat exchanger casing !! And other names , I don’t know what has failed , I’m not actually in the boat , but my step mother is there and she’s sending me pictures ! , this part ( thanks for giving it a name ! ), was glued on last summer apparently , and despite a considerable winter overhaul it was not dealt with ! Great answers so far , especially yours thanks.
Part of me thinks that it should be replaced with some sort of bolt on flange ?

 

[TactilePaul]

On mine the contraption added to the cap goes to an expansion tank.

Out of two engines this is fitted to one feeding the domestic water heater only, presumably to manage the extra amount of cooling plus the potential amount of air to be trapped in the extended circuit.

Same. I’m sure that most of these engines have the same set up ? But the neck was only designed to support a radiator cap , that is the problem

 

[TactilePaul]

First get rid of the junk attached to the rad' cap, that will prevent future problems. I'm now thinking about these low temperature welding rods that work with a blow lamp. One if these may provide a permanent solution. I have no experience of these but they look promising.

Can’t ‘get rid’ of the hoses to the expansion vessel ! Well I could temporarily and have no hot water I guess !! But the problem we first need to attend to is the broken filler neck

 

[Boater Sam]

Does the hose on the cap only go to the expansion bottle? If so a new bolt on neck will have the proper side spigot for that connection allowing a proper radiator cap with spring and valve to be fitted.

 

[Pete7]

Can’t ‘get rid’ of the hoses to the expansion vessel ! Well I could temporarily and have no hot water I guess !! But the problem we first need to attend to is the broken filler neck

Can't see you stripping down the heat exchanger and getting it welded whilst on holiday. So the suggestion is plastic metal, You will need to clean it spotlessly and be quick about adding the paste possibly in a complete loop around the neck without interfering with the radiator cap. Will it be enough to hold pressure? perhaps if you can get a good bond and if you find a crack or hole squish it it. Might last a fortnight for the hols.

https://www.halfords.com/motoring/p...stic-padding-chemical-metal-180ml-219474.html

Pete

 

[TactilePaul]

Can't see you stripping down the heat exchanger and getting it welded whilst on holiday. So the suggestion is plastic metal, You will need to clean it spotlessly and be quick about adding the paste possibly in a complete loop around the neck without interfering with the radiator cap. Will it be enough to hold pressure? perhaps if you can get a good bond and if you find a crack or hole squish it it. Might last a fortnight for the hols.

https://www.halfords.com/motoring/p...stic-padding-chemical-metal-180ml-219474.html

Pete

thanks, very much what i'd be doing I think, but decision has been made to sail home on SW wind tommorow,

 

[TactilePaul]

Does the hose on the cap only go to the expansion bottle? If so a new bolt on neck will have the proper side spigot for that connection allowing a proper radiator cap with spring and valve to be fitted.

hi, thanks, I'd like to know what you mean here by 'new bolt on neck'?, It would be great if the new set up had, as you say, just a rad cap, the two hoses are indeed for the expansion bottle (one to bottom, one to top (vent bubbles i presume)), i've been wondering would they not be better teeing into the flow or return to the cylinder/calorifier?. I know a bit about this stuff as i am a plumber! maybe the cap could just have a manual bleed valve (radiator bleed valve even). We feel that the extra load on the filler neck from this set up plus the vibration of the engine have caused this failure

 

[Mister E]

There is a copper tube that is part of the neck, it is used in vehicles to the expansion vessel.
A blanking cap is then used not a sprung cap.

 

[Boater Sam]

hi, thanks, I'd like to know what you mean here by 'new bolt on neck'?, It would be great if the new set up had, as you say, just a rad cap, the two hoses are indeed for the expansion bottle (one to bottom, one to top (vent bubbles i presume)), i've been wondering would they not be better teeing into the flow or return to the cylinder/calorifier?. I know a bit about this stuff as i am a plumber! maybe the cap could just have a manual bleed valve (radiator bleed valve even). We feel that the extra load on the filler neck from this set up plus the vibration of the engine have caused this failure

The Thermex bolt on neck has already been shown in the photo!