The V8 Owners Forum -

whats the best way to bleed cooling system on rv8, new thermo, water pump good, but still not circulating?

Flush out the rad?

They do silt up and can restrict water flow to a trickle

Ian

when i take off bottom hose tons of water comes out, so must be getting to bottom of rad?

Bung the hosepipe in the bottom rad outlet (stuffed with rags to stop leaks.

Remove top rad hose

Turn on tap and watch the crud move with a back flush!
Then do the same hose into top hose and flush engine out.

Reconnect bottom hose.
Fill through engine till water comes out the rad
Reconnect top hose.

then fill up header tank.

Start engine and the header tank should bubble out the air that was present in top hose / rad (Some need to be burped by squeezing top hose)

Let it run a couple of minutes
and feel for heat in top hose rad and bottom hose.

Oh yes have your cabin temp set to cold - thus forcing water through the rad as opposed to through bypass and heater matrix

Should work reasonably well

Ian

cheers for that, will try in morning.

Another tip is jack the front of the car up then the air goes to the front of the engine where it can be purged.

Same as the Ian and Marki - Click HERE - you should be able to adapt the process to your car. Let me know if it works.

This is with an Offenhauser manifold? I wonder if there are any special features of that manifold.

I think some pics of the hoses might be helpful as it might be that there's an error in the plumbing.

Chris.

ChrisJC wrote:This is with an Offenhauser manifold? I wonder if there are any special features of that manifold.

I think some pics of the hoses might be helpful as it might be that there's an error in the plumbing.

Chris.

I have an Offenhauser manifold.
My pipework on the mainfold is, the small pipe on the rear goes to the heater, a pipe from the heater to the vertical outlet on the water pump and the rear water pump outlet goes the the small outlet on the thermostat housing. I have drilled a 4mm hole in the stat just to help and if filling from empty, I back fill through the heater.
Stu

finally got it bled. My pipe works is as follows, pipe from thermo to top of rad, bottom of water pump to lower rad, active pipe on back of water pump to heater , back of inlet manifold to heater, working great now.