Volvo oil cooler overhaul, TAMD31-P. Parts manual error?

Looking for impeller pieces and I hear a new rattle in the oil cooler (just downstream from the SW pump. Anyone removed and overhauled this oil cooler??

Looks like the HX above it and the expansion tank will have to come off first. The parts and service manual for this "later version" 859525-8 (without a "narrowing waist" in the center) do Not show there is a removable end cap casting on the inlet end (where impeller pieces likely are). And hence no seal to purchase. But by inspection, there is an inlet end cap where the inlet hose enters. Confused. Looks symmetrical- will the outlet end cap seal fit the inlet cap??

Please say whether you've actually disassembled the new type for later TAMD31's.

Thanks very much for help

 

Not shure which version you mean, but generally, the engine oil cooler looks like what you find in "www.marinepartseurope.co/sv/volvo-penta-sprangskiss-7745910-26". There are two sealings; o-ring on the oil side and one packing on the water side. Look carefully for corrosion damage between the tube bundle "frame" and the aluminium housing. Any pitting is sign of trouble.


....And it should come off without dismantling other parts.

 

Thanks for replying. Your link didn't work for me. The following at MarinePartsEurope.com shows the one for my engine.

http://www.marinepartseurope.com/en/volvo-penta-explodedview-7742700-26-1714.aspx

Note there is no removable end cover for the other hose, the inlet side where impeller pieces might be trapped. Mine has a removable inlet end cover held by 3 bolts. If the diagram is right, does it mean the inlet hose nipple is part of the body casting???

Thanks for trying to help. I agree with your last comment. I will have to remove the HX and tank only because there is no side access on this installation.

 

diagram is confusing

based on my experience with an earlier model I would say the gasket 5, goes between the cooler and the housing and not as shown.

The o-ring is in a groove deep inside the housing and seals on the side of the circular end cap of the cooler - that needs to be checked to be free of burrs and lightly 'polished' - you dont want to remove material - but it needs to smooth and free of corrosion so it will slide in without damaging the o-ring (LUBE!).

On older units don't be surprised if the o-ring has been 'augmented' with a smear of orange silicone sealer making it a B#tch to remove, but given the cost and availability of replacement housings, any pitting in the vicinity of the o-ring groove might make that a necessary evil. If it's being difficult, might be better to pull the 4 bolts / end plate only and then back flush the debris out, the oil cooler matrix is expensive and don't know what availability is...

 

Ok, your link shows the same cooler as mine. This OC has a fixed forward (inlet) end. The o-ring is positioned in the housing so that it is sealing against the cylindrical (forward) part of the tube bundle. The gasket (#5) goes between housing and the outlet cover.

Some coolers came with a detachable inlet cover, as yours, but the inner structure is basically unchanged. Unfortunately, it is not possible to dismantle the inlet end for cleaning (in spite of the Three bolts) with cooler in situ on engine; better to remove the OC.

 

You can try taking off the hose and cleaning it with a vacuum cleaner. Also back flushing.

 

Nope, there is a pocket below the inlet connection in the cap, where debris will collect.

 

After taking photos of my oil cooler, I realized I misidentified it in my question. Sorry. Three bolts each end. It is as shown on:

http://www.marinepartseurope.com/en/volvo-penta-explodedview-7742700-26-9730.aspx

I'll try to attach photos. Thanks to all for your help- still have some questions.

1) If any pitting is found. what can be done? Once aluminum corrosion starts, it will continue unless the corrosive salt byproducts are removed- ground out and smoothed. Does anyone alodine (conversion coat) and paint it.

2) The four O-rings cost $70. I plan to replace but won't if no nicks and you think it isn't needed. Nine yr old engine, 500 saltwater hours.

3) Part #7 called a "washer" is very expensive. I thought it was a gasket to be replaced, but now think it's metal with no need to replace.

4) The cooling insert is likely stuck in the housing. Stupid question, but what is the benefit of removing it? Hammer and wood block and care?

5) I have to remove the main HX. Are the 3 "sealing strips" required when disassembled? $174 each.

6) Are there alternative sources for buying the VP parts?

Thanks so much to all.

 

OK, here we go:

1/ There is no need to remove the tube bundle from the housing if it is stuck, unless there are major signs of leakage. From the pics, this does not seem likely. Any pittings are normally first found at the entrance end of the housing. This is due to the combination of brass in the tubes and alu in the housing, which leads to the corrosion of alu-parts if saltwater may slip past the o-rings.

2/ O-rings are standard metric size and can be bought in suitable materials from most engineering stores at a fraction of Volvo prizes.

3/ The "washer" is actually a metal spacer that is separating the oil and water spaces at the inlet. Its function corresponds to the outlet flange on the tube bundle. No need to replace, but check that it is flat and without scratches and "wrinkles".

4/ See "1" above. If necessary to remove, heat the housing to about 100 Centigrades.

5/ Not clear what "strips" you mean?

6/ Try a "Sierra" dealer.

Now, having said that, please don't take offence if I recommend that you ask a professional mechanic for assistance. This is a routine job, and the questions you asked reveal a slight lack of "fiddling experience".

 

Thank you for your patience and advice. Your last point was a fair comment.

1) But if I have aluminum pitting, is there anything to do to lengthen its useful life?

5) The HX "seal strips" are as shown on:

http://www.marinepartseurope.com/en/volvo-penta-explodedview-7742700-26-1698B.aspx

The diagram does not help explain their function. The price I'm seeing must be a mistake.

Thanks again

 

First the prizes seen in the link; it says SEK, meaning Swedish Crowns, including VAT. Exchange rate today is 6,71 SEK per USD.

1/ Within reasonable limits, any pitting of the o-ring seats can be repaired by TIG or even MIG welding, followed by machining new seats in a lathe. In some "mild" cases it is even possible to machine the seat to an oversize ring dimension without welding. Considering the cost of a new housing/cooler, this is a good investment. NOTE: don't try any kind of chemical putties, they do not stand the sliding length changes between the tubing and the housing, due to temp variations.

Any leakage that might cause pitting damage will also be seen on the outside perimeter of the housing; salt water incrusts will form. There is none to be seen in your pics, so don't worry about that too much.

2/ These "stripes" are short, straight seals that stick to the horizontal dividing wall inside the end caps, stopping incoming fluid from going directly to the outlet. There is no reason why you should open the HX, so don't worry about them.

Good luck!!

 

Thanks for your careful explanation. I understand.

The only US website for the HX "seal strips" referenced a new Volvo part number with the absurd price of $178 each. Must be a mistake and as you say not needed.