MD22LB radiator cap pressure?

[Paul Holmes]

Can anyone tell me the pressure rating (kPa or PSI) of the radiator/heat exchanger cap? (I can't read mine). It's for an MD22LB model. Also any suggestions for suppliers would be helpful (Volvo want £52 for one!!)

Thanks

Paul

 

[VicS]

According to the parts list 75kPa. (0.75 bar, 10.9 psi )
See http://www.marinepartseurope.com/en/volvo-penta-explodedview-7746710-26-573.aspx
Only 26 EUR


same cap as my Volvo car

 

[gpcgpc]

it seems 75kPa is for the cap of the expansion tank, do you know if the cap on the exchanger has the same pressure value?

 

[robmcg]

https://parts4engines.com/collectio...rts/products/volvo-penta-md22-header-tank-cap

 

[VicS]

it seems 75kPa is for the cap of the expansion tank, do you know if the cap on the exchanger has the same pressure value?

With a separate expansion tank I would expect the cap on the expansion tank to be a pressure cap but the one on the heat exchanger to be a fixed cap.. You only need one pressure cap. on the system

But looking at this again I see that there are two different systems which may apply

. . . .

The earlier type has a fixed cap (#11) on the heat exchanger and a pressure cap (#4) on the expansion vessel. The pressure cap on this one is rated at 30 kPa

The later type has the connections for the expansion tank fitted to a cap, #8, on the heat exchanger and a pressure cap (#3) rated at 75kPa on the expansion tank.

Best to refer to the official parts lists at MD22L - marine diesel engines

 

[gpcgpc]

Thanks, what I need is a cap to replace my actual exchanger cap; at the moment I have not an expansion thank but I want to add it.
The new cap should have the same opening pressure as the actual one (and I need this information about the correct pressure) and "also" a valve (in the center usually) that the actual cap has not, to allow the coolant liquid to return to the exchanger from the expansion tank when it cools down.
So that I can attach any expansion tank also a very little one to the actual black rubber tube that comes out from the actual heather cap; when the cap opens at a certain pressure (75 kPa??), the liquid will go in the expansion thank, and when the system cools down, the new cap will allow the liquid to return in the exchanger through the valve that the current cap has not.
It seems impossible to find the information about the correct opening pressure, I guess it is 75 kPa but it is not sure....
I'm pretty sure that such cup with this valve exists, I only need to know the correct pressure.
Otherwise I stay with current cap, and I simpy install an expansion tank no to lose the liquid ,when required with the system cooled I will open the cup to allow the few liquid to return in the exchanger.

this is what I mean, I suppose I need a 30kPa expansion tank cup, and maybe the cup from the old system 845587 (unknown opening pressure, but > 30kPa, maybe 75? who knows excactly?):