Volvo DPE where does the water go in for rydlyme ?

simonfraser

simonfraser

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Shows the cooling water in / out, still not clear to me what i am looking at.

The smaller hose, marked 6 and 9 is where the intake is ?
Can i extend this and drop the extra hose in a bucket to flush with rydlyme or similar ?
Then let the cleaning fluid out of the bottom of the leg ? Using a big bucket of course.

(I will need a circulation pump and take the impeller out)
 
Why do you want to take it through the leg? I'd be very wary doing a circuit that way as without the motor running when it goes through the exhaust elbow it has the potential to also run back into the exhaust manifold and if any exhaust valves are open... (or is this just peculiar to my setup?)
My understanding is the use of this is really to clean the coolers and heat exchangers of limescale build up. I'd keep the circuit to just the oil cooler, interchanger and heat exchanger.
 
Not going to get to the exhaust valves surely as the KAD 44 has a heat exchanger for the engine coolant ?
It’s not cooled directly with seawater.

The intake is no major problem to tap into via the engine bay, but the hose diameter is way too big for a ‘standard’ flushing hose, so that would def need an adaptor. Thought it would be easier and less messy inside to do it all from the OD leg.

But happy to take advise from all you guys.
 
rafiki_ said:
Would you not be better off dismantling the heat exchanger, and soaking it in rydlyme? I also would not want to run acid through the leg.
Click to expand...

Agree on this point. It’s better to take the exchanger off and treat it separately. Volvo Paul will be able to explain the technicals better than me though.
 
rafiki_ said:
Would you not be better off dismantling the heat exchanger, and soaking it in rydlyme? I also would not want to run acid through the leg.
Click to expand...

I have recently taken off all my coolers / Heat exchangers for cleaning, KAD44's looked like the oil cooler was the 1 causing slight issues it showed signs of restricted flow.

Was a bit of a fiddle taking them off , took most of the day for 2 engines .

Getting them back on will be a challenge .
 
rafiki_ said:
Would you not be better off dismantling the heat exchanger, and soaking it in rydlyme? I also would not want to run acid through the leg.
Click to expand...

The heat exchanger is a 1 piece item in the 31 /41 /42/43/44/300 motor , just the end cap to remove .

It seems this forum is full of rydelime and overheat threads just lately .
 
volvopaul said:
The heat exchanger is a 1 piece item in the 31 /41 /42/43/44/300 motor , just the end cap to remove .

It seems this forum is full of rydelime and overheat threads just lately .
Click to expand...

Paul, could you give a brief description of how you would go about de-scaling the cooling system of a KAD44DP and how long it should take to do?

I'd be very grateful :)
 
Just had a long reply from rydlyme re flushing an inboard
Anything that goes in the water will be ok with 50% dilution of rydlyme
But it will eat your anodes, not the Aluminium leg as it is safe for Aluminium heads

If you flush via a leg you’ll have to remove the anodes

Be just as easy to disconnect the exhaust and drain that in a bucket
Then pump it in from the bucket via an extension of the S intake, again will need to be disconnected
Take the impeller out

Or of course take the inter cooler out, but according to the manual mine has a steering hydraulic cooler too

That make sense ?
 
I have seen a few lads in the SoF flush through when the boat is lifted .
Get a large blue drum under the leg fill it with what ever ,presume brick cleaner or Rydlime solutions .
Start up ,place a wooden board over the exhaust exit to defect the outgoing water / descaler -back into the bucket and let it circulate, turn off wait , restart etc - go for a long lunch - finish by fresh water only usually with muffs .

They do this 1st straight after lift - and pressure wash - them the usual service / anodes / drive oil / trilux AF

You need an infra red thermo gun - spotted on top of the thermostat housing , guages are inaccurate- spade corrosion and loom resistance can give false highs in old boats .

But as said with VP there’s issues of the base metal ally corrosion from leaking O rings in the system .
This means new O rings no longer fit / seal and you are looking at a new unit €€€ +++
Also oil contamination of the airside of the CAC is not addressed by the raw water de scale .

It’s every guys decision, scrimp —- now and again descale the raw water in situ - then a strip down , or never do a strip down , or do it by the book ,( service book has the interval - time ) or strip down when the temps creep up .

Personally MAN s that I have (2876 striaght 6 like volvos ) completely drain out when not running , so seem to last , running temps stable .
The engines are tall and the cooling gear is as high as possible above the WL .
I think low mounted Vs @ the WL - seawater sit after shutdown- stewing in the heat = scale formation.

How ever it does not get round the O ring set and weep - but in threory my system drains down .
Spoke to a MAN engineer. The book says every 2 years .
Only folks that do that are newbies mindful of warranty companies compliance .
Rest of his client base every 5 y or if temps creep up .

I had my KAD 300 ,s stripped down at year 5 by the local VP agent ,and the turbos sent away ,and the water pumps refurbed
€5000 - can,t remember if that inc a bellows service , but inc a full engine service - oil / filters etc .

Whist they never let me down the KAD 300 / DPG combo , having had the MAN s now three years I don,t spend anything near the amount on service / running .
Of course my fuel bill is 2x , but some how mentally that’s comes out of a different silo .
 
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