after fixing some tiny leeks in my cooling system (new rad and hoses) and the system is now holding pressure, so no more leaks.

However i can't seem to be able to fully bleed it.

i have been following the guide on here, of basically jack front up slightly, idle engine up to 3 bars, then every 2 mins shut off engine and open front bleeder.


Now I've done this many times, and the heater eventually gets pretty warm.

However when out driving the heater gets much hotter, and when i slow down it cools down to eventually cold again once left at idle a few mins.

So there is obviously a big lump of air somewhere i don't seem to be able to budge!

I haven't touched the rear bleeder, (I'm not sure where it even is)

Ive also tried leaving the rad cap off, but i just seem to end up with a water fall and pissing coolant everywhere?

Am i missing something here?

Cheers

 

Are you getting air each time you open the bleeder, and adding coolant each time to replace the air?

 

I tend to get a tiny hiss, then a nice flow of coolant. And yes i brim the rad each time.

Its almost like the air is not getting to the bleeder, stuck in the heater or similar?

 

Are you running it up to 2500 RPM during the 2 minutes? This step was necessary to fully bleed the system for me, prior to that the heater was not getting hot enough. After I did that, squeezed the air out, and topped the radiator off one last time, the heater will blow hot at all times.

 

If you're gonna run with the rad cap off try using a funnel that can fit inside the spout so you don't make a mess. Just keep squeezing that upper rad hose until your funnel now filled with coolant isn't showing any bubbles. Then with a hand pump, or turkey baster or whatever, put the extra coolant in your overflow. Careful it's hot. Once you do that and put the cap back on, hold the hose squeezed, then barely crack the bleeder just to make sure only coolant comes out right away.

P.S. the rear bleeder is that little rubber nipple on the firewall, it's part of the heater circuit, technically the highest point in the system. If air is less dense than water/coolant it follows that it should be displaced to where there is no water/coolant, ie the highest point in the system.

 

Thanks, that seemed to be working, however the air bubbles were never ending...

So i put the pressure tester on while still hot, and the pressure was dropping! So obviously a leak causing it to suck in air?
However when cold it holds pressure!

So a good look, and no noticeable puddles, but at the rear by the intake manifold looks a bit damp.


So thought it would be a good time to replace the intake manifold gasket, and this is what i found:





And have a feeling this may be the culprit? the o ring was pretty hard and brittle!




So have ordered a load of new parts, including the heater hoses, as they looked a bit past there best, and will have to try again!

Not looking forward to re-assembly mind, took some serious swearing to get them bolts out!!!

 

At least it's not the lower radiator hose.