nigelstgeorge
Well-Known Member
How easy is it to remove, clean and put back the cooling tube in a Volvo MD22L. Also what is the best way of cleaning the salt deposits and build up on the tube? Many thanks in advance.
Volvo MD22L removing and cleaning cooling tube in heat exchanger
- Thread starter nigelstgeorge
- Start date
Cliveshep
Well-Known Member
If it is the same as Bowman heat exchangers from memory you've got a rubber bell at each end, a bit like the flush cone on the back of old toilets where the flush pipe was connected. There are hose clips on both the larger and smaller diameter parts of the bell. Undo all clips at both ends and pull off one bell which will reveal the central tube which you can then withdraw. That's all I can recall if that is of any help?
nigelstgeorge
Well-Known Member
thanks lets hope it is that easy. Obviously need to drain down the heat exchanger first.
VicS
Well-Known Member
Depends if we are talking about MD22L-A or MD22L-B.
If the former then yes remove the rubber end caps, withdraw the tube nest and clean in a bucket of central heating boiler descaler (eg Fernox DS3), Rydlyme or even diluted brick cleaner (hydrochloric acid)
The MD22L-B is rather different and looks a bit more of a fiddle to remove and refit the tube nest with bolted on end covers and various O ring seals etc.
Yes you do have to drain the cooling system first although it will drain itself quite quickly when you remove the end caps if you dont!
If the former then yes remove the rubber end caps, withdraw the tube nest and clean in a bucket of central heating boiler descaler (eg Fernox DS3), Rydlyme or even diluted brick cleaner (hydrochloric acid)
The MD22L-B is rather different and looks a bit more of a fiddle to remove and refit the tube nest with bolted on end covers and various O ring seals etc.
Yes you do have to drain the cooling system first although it will drain itself quite quickly when you remove the end caps if you dont!
nigelstgeorge
Well-Known Member
Can we continue this further as I tink I must be a MD22L-A. I have drained down today and taken the end covers off but canot get the tube out. It wiggles around a bit but will not push out. Any ideas please.
VicS
Well-Known Member
I see you have started another thread ... naughty boy.
Block of wood and gentle taps with a heavy hammer perhaps
Block of wood and gentle taps with a heavy hammer perhaps
nigelstgeorge
Well-Known Member
thanks for answering both threads but I really wanted to get on top of this problem. There is also a seal that goes round the cooling tube which must come out at the same time as the tube and must be re-inserted very carefully. The workshop manual which is useless suggests looking through the filler cap hole to make sure it is aligned. I have looked and one cannot really see anything even with a torch. Is this a job you have actually done as I do not want to break to tube hitting it and causing even more problems. Thanks
Ruffles
Well-Known Member
Is there a tiny hole on one side of the stack? I think this goes at the top so they may mean you should be able to see the hole while looking in the filler cap.
The hole is to prevent an air lock.
The hole is to prevent an air lock.
VicS
Well-Known Member
No I haven't done it.
It looks as though it should be such a simple job.
What you call a seal is presumably what is called a "sleeve" in the parts list. The end caps are the seals.
There are no other seals listed, or a need for any.
I reckon you will just have to use what force is necessary. It's either so crudded up on the freshwater side that the deposits are holding it or its is just that sleeve that is stuck. You may have to sacrifice that and buy a new one. Only €55 or €62 though depending on which of the two variations you have (What the hell is it made off to cost that much?)
A sensible alternative might be to consider cleaning it in situ.
Lets us know what you found when you have succeeded
It looks as though it should be such a simple job.
What you call a seal is presumably what is called a "sleeve" in the parts list. The end caps are the seals.
There are no other seals listed, or a need for any.
I reckon you will just have to use what force is necessary. It's either so crudded up on the freshwater side that the deposits are holding it or its is just that sleeve that is stuck. You may have to sacrifice that and buy a new one. Only €55 or €62 though depending on which of the two variations you have (What the hell is it made off to cost that much?)
A sensible alternative might be to consider cleaning it in situ.
Lets us know what you found when you have succeeded
nigelstgeorge
Well-Known Member
I wish it really was 55 or €62 according to volvo online spares it is circa €1,600 see http://www.marinepartseurope.com/en/volvo-penta-explodedview-7744150-25-306.aspx
That is why I am being so cautious and not wanting to hit it too hard.
That is why I am being so cautious and not wanting to hit it too hard.
nigelstgeorge
Well-Known Member
Thanks - I'll have a look tomorrow
VicS
Well-Known Member
[ QUOTE ]
wish it really was 55 or €62 according to volvo online spares it is circa €1,600 see
[/ QUOTE ] You misunderstand. I was suggesting you sacrifice the sleeve (That's whats €55 or 62 ) by cutting it away if that is what is stopping the tube nest from coming out.
And yes I looked the price of the tube nest too! That's really outrageous for a little bundle of tubes. A competent model engineer could make that for a tiny fraction of the price.
Re cleaning in situ
Now you have the end caps off you can see the state of the tubes internally. I'd expect that to be where it would need descaling.
Perhaps using the endcaps you you could manage to soak the insides in some descaler (Fernox DS3, Rydlyme or something similar)
Can you see sufficient through the filler to judge whether the freshwater side is badly scaled. Cleaning that along with the whole of the engine cooling circuit could also be done if necessary.
wish it really was 55 or €62 according to volvo online spares it is circa €1,600 see
[/ QUOTE ] You misunderstand. I was suggesting you sacrifice the sleeve (That's whats €55 or 62 ) by cutting it away if that is what is stopping the tube nest from coming out.
And yes I looked the price of the tube nest too! That's really outrageous for a little bundle of tubes. A competent model engineer could make that for a tiny fraction of the price.
Re cleaning in situ
Now you have the end caps off you can see the state of the tubes internally. I'd expect that to be where it would need descaling.
Perhaps using the endcaps you you could manage to soak the insides in some descaler (Fernox DS3, Rydlyme or something similar)
Can you see sufficient through the filler to judge whether the freshwater side is badly scaled. Cleaning that along with the whole of the engine cooling circuit could also be done if necessary.
nigelstgeorge
Well-Known Member
Ok - now out following your advice with hammer and wood. The sleeve was distorted so have ordered a new one ready to re-install. Now think that before it goes back in it should somehow be pressure tested with each of the tubes to see if there is a pin prick leak which might be the reason I am loosing coolant.
VicS
Well-Known Member
Relieved to hear you got it out OK. Checking for small leaks sounds a good idea.
nigelstgeorge
Well-Known Member
Now everyone can laugh at this. The engineering company in Rochefort where I have ordered the volvo rubber sleeve has now said that the volvo cooling tube should be changed at 500 hours. I was not amused and have asked for it back to take to a radiator specialist for checking. My estimate is that he would have made 30% profit circa 530 euros just on ordering the part for me. How can you trust these guys. The company was JS Marine at Rochefort who originally said the fault was my salt water impellor and tried to change it when I had only put a new one in 6 months ago!!!!!!!!!!!!