Volvo MD11C "core plugs" or "frost plugs"
 

Last fall one of the plugs on my Volvo MD11C popped out.
I am looking for comments or information from anyone to whom this has
happened.

What should I watch for when fitting in a new plug?

Otherwise the motor run ok.
Gabriel

Volvo MD11C "core plugs" or "frost plugs"
 

"Gabriel Latrémouille" wrote in message
ers.com...

I've had several Volvo MD series engines and never experienced this.

Is there a possibility that someone put dockside hose pressure on the
coolant system?? Maybe when flushing?? If the discharge were closed or
restricted, the pressure could not only do this, but damage the waterpump
seals.

However I have replaced core plugs in other engines I have rebuilt.

A core plug is simply pressed into a machined open in the casting. In fact
there is seldom any shoulder behind, to keep it from being pressed all the
way into the coolant passage.

I recommend that you examine the machined surface where the new core plug
would seat. Make sure you don't have excessive rust and pitting. There
should be at least 3/16" clean, machined surface to seat and seal. If there
is pitting from coolant leakage in the past and there is still sufficient
good metal to retain the new plug, they you could use some High Temp RTV on
the plug. Other wise this should be a metal to metal seal, dry press fit.
You can purchase brass replacement plugs from Volvo and just tap them into
place with a wooden dowel until the plug lip is flush with the casting
surface.


--
My opinion and experience. FWIW

Steve
s/v Good Intentions

Volvo MD11C "core plugs" or "frost plugs"
 

"Gabriel Latrémouille" wrote in message
ers.com...

I've had several Volvo MD series engines and never experienced this.

Is there a possibility that someone put dockside hose pressure on the
coolant system?? Maybe when flushing?? If the discharge were closed or
restricted, the pressure could not only do this, but damage the waterpump
seals.

However I have replaced core plugs in other engines I have rebuilt.

A core plug is simply pressed into a machined open in the casting. In fact
there is seldom any shoulder behind, to keep it from being pressed all the
way into the coolant passage.

I recommend that you examine the machined surface where the new core plug
would seat. Make sure you don't have excessive rust and pitting. There
should be at least 3/16" clean, machined surface to seat and seal. If there
is pitting from coolant leakage in the past and there is still sufficient
good metal to retain the new plug, they you could use some High Temp RTV on
the plug. Other wise this should be a metal to metal seal, dry press fit.
You can purchase brass replacement plugs from Volvo and just tap them into
place with a wooden dowel until the plug lip is flush with the casting
surface.


--
My opinion and experience. FWIW

Steve
s/v Good Intentions