Volvo AD41 Bloody O Rings.

[hlb]

Volvo seem obsesssed with O rings. Pipes held together with just a hope and a prayer, they always leak eventually.

Can you imagine a two ft long pipe, just held in place by one little screw in the middle of it. I cant think of any way of changing the design.

Would putting some sylicone sealer round the O rings help.

 

[tinkicker0]

Volvo seem obsesssed with O rings. Pipes held together with just a hope and a prayer, they always leak eventually.

Can you imagine a two ft long pipe, just held in place by one little screw in the middle of it. I cant think of any way of changing the design.

Would putting some sylicone sealer round the O rings help.

Not silicone. You could try a non hardening compound such as Hylomar to bed em on. Many O rings rely on contact with the sunbstance they seal to swell up after fitting though.

 

[volvopaul]

o rings only leak when the surface its in contact with is worn, uneven or misshaped, so have a look at the housings if you have fitted new rings and there is still a leak.

On hydraulic systems we would be totally lost without them as a gasket will not take the pressure an o ring will take.

 

[hlb]

o rings only leak when the surface its in contact with is worn, uneven or misshaped, so have a look at the housings if you have fitted new rings and there is still a leak.

On hydraulic systems we would be totally lost without them as a gasket will not take the pressure an o ring will take.

Well I've never found a mechanic that had a good word for them. Paticularly the pipe that runs across the top of the engine.

 

[aquatom]

I am a mechanic and much prefer o-rings to gaskets. How many impeller pump cover plates with gaskets have you seen leaking and how many leak with o-rings?

 

[hlb]

No cover plate problems, but then there easy fixed, if I did have a problem. Just O rings. But I'm just trying to stop them leaking, It's no good telling me they dont leak. The starboard engine never leaked, till it got a new oil cooler, now leaks, as does the port one to a lesser or greater degree. Having said that the port engine has mostly always leaked, I want a fix, not a sermon.

 

[aquatom]

Sounds like the pipes may have been bent when the oil cooler was replaced. These pipes need to be removed carefully and not forced with some of the clamps still conected. When the seals are removed do the ends of the pipes sit centerally in the sockets?

 

[ccscott49]

Volvo seem obsesssed with O rings. Pipes held together with just a hope and a prayer, they always leak eventually.

Can you imagine a two ft long pipe, just held in place by one little screw in the middle of it. I cant think of any way of changing the design.

Would putting some sylicone sealer round the O rings help.

Sounds like the pipes were very slightly bent when removed at some point, they have to fit exactly in the centre for these "O" ring seals to work, I think they are an abortion also! But I know of no other way of fitting them. Cack handed mechanics are the normal culprit.

 

[oldgit]

Gooinatube

"Would putting some sylicone sealer round the O rings help."

Just about everything on my heat exchanger/cooling system was shoved back together complete with a smear but far more frequently with entire dollops of sealant.
Also makes it easy to spot when stuff was fixed,due to wether orange goo or blue goo was handy during last bodge-it-session.
Sometimes use the expensive Hydrolamar ? with the nice solvent smell for some jobs but the silicone stuff clogs up bigger gaps better.

My extensive collection of half used tubes of goo is going to be a collectors item one day.

 

[Wiggo]

Are you talking about the air intake pipes, Haydn? How do you know they're leaking?

 

[rosssavage]

Don't know much about the AD41, but I really like the design of my TAMD 61A cooling pipes, complete with 'o' ring seals on all metal pipework - no nasty rubber hoses to perish or split as seem to be plastered all over modern engines to save cost. I've never had big problems with my donkey's, but had some fun with a mates TAMD 60's I worked on last year.

Fix was a VERY good clean of both the pipe ends (rubbing around the pipe, not up and down or water leaks along the 'grain' of the fine sanding...) and cooler ports. This didn't eliminate all leakage, so a smudge of Hylomar was used - this did work, but I'd prefer not to use it as it prevents full contact of the 'o' ring and could prevent proper swelling of the seal. Poper fix would (I think..) have invloved renewing the pipes on thirty year old engines, but my poor friend had had enough nasty (££) surprises during the engine mainenance.

Try hylomar first, and lots of patience and dis and reassembly until it works. Don't envy you...

 

[ccscott49]

Don't know much about the AD41, but I really like the design of my TAMD 61A cooling pipes, complete with 'o' ring seals on all metal pipework - no nasty rubber hoses to perish or split as seem to be plastered all over modern engines to save cost. I've never had big problems with my donkey's, but had some fun with a mates TAMD 60's I worked on last year.

Fix was a VERY good clean of both the pipe ends (rubbing around the pipe, not up and down or water leaks along the 'grain' of the fine sanding...) and cooler ports. This didn't eliminate all leakage, so a smudge of Hylomar was used - this did work, but I'd prefer not to use it as it prevents full contact of the 'o' ring and could prevent proper swelling of the seal. Poper fix would (I think..) have invloved renewing the pipes on thirty year old engines, but my poor friend had had enough nasty (££) surprises during the engine mainenance.

Try hylomar first, and lots of patience and dis and reassembly until it works. Don't envy you...

Rubber (silicon, the blue ones) hoses are neither nasty or cheap, if you use silicone hoses. I have never had a silicone hose split. On my engines at over 3000 hours and have never even replaced one, I check them at service times.

 

[DAKA]

A temp bodge cock up nearly sank my last boat, volvo penta 41 engine o ring

Under the raw water filter the two inlet/outlet pipes from the impeller are held in place by one grub screw and a double half moon 2 mm metal plate and of course your two orings

plate had rusted and wouldnt seal and \I was due on holiday.

took plate off, machine sanded level ,painted and screwed back on.

didnt stop the leak completely as metal was now 30% thinner/weeker but completed the holiday so temp bodge worked, job done.
over winter i had a new plate made 4 mm thick.

Now the problem

the grub screw went into a brass holder and as it was over tightened the brass holder was partly pulled out of the plastic raw water filter(couldnt see this) first time out the grub screw pulled out the filter and the raw water was directed straight into the bilge.


only time the VP 41 let me down................well sort of, it was sold at that point.

Anyway, my suggestion is not to bodge but to replace any worn parts before they fail and cost 10x as much.

 

[hlb]

Rubber (silicon, the blue ones) hoses are neither nasty or cheap, if you use silicone hoses. I have never had a silicone hose split. On my engines at over 3000 hours and have never even replaced one, I check them at service times.

Colin, This is nothing to do with rubber hoses.

I've got a steel pipe, about 18 inches long, with a 90 Deg bend at one end. It's about 2" bore. Each end has an O ring. The pipe allows for nothing except perfect fit. Theres a weedy clamp half way down the pipe with about a 10mm screw in it.

Years ago, I could not understand it, I thought the pipe must be welded in at each end. So called the engineer out. He undid the little screw and to my amazement, the pipe fell off.

 

[ccscott49]

Colin, This is nothing to do with rubber hoses.

I've got a steel pipe, about 18 inches long, with a 90 Deg bend at one end. It's about 2" bore. Each end has an O ring. The pipe allows for nothing except perfect fit. Theres a weedy clamp half way down the pipe with about a 10mm screw in it.

Years ago, I could not understand it, I thought the pipe must be welded in at each end. So called the engineer out. He undid the little screw and to my amazement, the pipe fell off.

I know its not, I was replying to the bloke that said, rubber hoses were cheapo crappo. I know those VP pipes and dont like them. Also the little metal plates corrode, just dont like them.
I would much rather have the silicone hoses and stainless pipe between them, as you can see and feel the condition of the silicone ones.

 

[Bilgediver]

Sounds like the pipes were very slightly bent when removed at some point, they have to fit exactly in the centre for these "O" ring seals to work, I think they are an abortion also! But I know of no other way of fitting them. Cack handed mechanics are the normal culprit.

I agree.....so lng as correctly takenpart and rre assembled they do a good job however take short cuts ad bend the pipes and you will be treated to leaks.

As others have said if a seal leaks then remove thwhole pipe correctly even if it means removing or slavckening of a cooler etc and make sur thepipe has the corrct set so that it enters the sockets at both ends and sits centrally within them. Sore tidily so no one walks on them when doing repairs.

 

[rosssavage]

From the 'bloke' slating cheapo hoses - I was doing exactly that! NOT the blue silicone ones as I have no experience with them. The BLACK RUBBER hoses which I mentioned are the ones I'm referring to! They do eventually perish and can split and have very low damage tolerance compared to metal pipes, and as an (now ex) aircraft engineer they reek of cheap design on modern engines. You're average Boeing does not use black rubber pipes in the engine, they use metal pipes with - guess what, o rings to seal...They are retained in a much better way than VP, granted. They also use some silicone pipes for non critical systems, but never rubber where it counts.