Advice please: Bleeding 328 coolant

It should be warm enough to get the thermostat open.

Better if the water pump is circulating the water (and air).

It has a slot down one side, so just loosen it until water and/or air comes out. When it's just water, it's bled.

Yes and no. If you keep the tank topped up to the correct level, you shouldn't be getting air into the sytem. But most cooling systems operate under a little pressure, which raises the boiling point of the coolent.

I've found that a pressure bleed (pumping pressure into the overflow tank) works better than depending on the water pump. You can get a fancy pressure attachment cap to do this. But I've found that a hand pump, a thick plastic bag, and a few large rubber bands will put enough pressure on the system to get the air out. (It doesn't need a lot of pressure.) It's not a perfect seal, but you can just keep pumping the pressure back. (I use one of those hand operated "brake bleed" pressure/vacuum pumps.) (Top up the overflow tank first, so you're not putting more air into the system.)

You need to bleed the radiator valve and then the one near the water pump.

And don't forget to open the heater controls to full hot, to get the air out of the heater cores.

 

Jeremy,
There are a tremendous number of threads on radiator bleeding...just try the archives...located in the upper left hand corner of the page.

Here is one from another site. Personally, I would not bother bleeding from the water pump housing, I tried once, no air came out, and I dropped the damn screw...

BTW the bleed screw on the radiator has a hole in it, so it does not need to competely come out...not the same with the water pump housing..and why I dropped the screw.

Coolant should be 6cm from the top of the expansion tank neck when cold. If you have rust on the neck, clean it up with a scotchbrite pad, not having a tight seal could cause leaks. Good luck.

Posted on Friday, September 19, 2003 - 07:57 am:

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David,

of course I have my way of bleeding the Ferrari Cooling Systems because one finds out early on in a carreer that certian cars just like being difficult and uncooperative.

I don't have any tricks other than the paitience to play with and fuss over the engine while the whole process plays out.

First rule as you know of course is that the coolant level should remain as high as possible in the Header Tank to facilitate Gravity Feeding. Second thing is cap should be off to prevent a vacum from forming anywhere in the system.

I start with cold/warm engine with the cap off, coolant close to the brim, heater valve open and car on flat ground or if in a driveway slightly inclined in the front is ok. Then I just start the engine and let it begin the process of gravity feeding and pushing the air into the radiator to be bled off at the bleeder valve. The process takes quite some time as it's neccesary to run the engine until well after the T-Stat has opened and the fans have begun to operate. About mid-way thru this process, just befre and continueing after the T-stat opens I periodicaly raise the rpms and carefully punch the throttle a few times to increase flow speed and volme to help with the air transfer towards the front. While I'm doing the fiddling with the throttle and pacing/circling around checking & inspecting I'm bleeding any new accumulated air from the bleed screw multiples of times. I'd guess my normal procedure takes 20-30 minutes at least . Once everything has been throughly checked and all systems inspected for proper operation & temp I finally shut off engine, check level in the tank and replace the cap. Then a short road test of a mile or so varying speed/rpm conditions and back, park, shut down and perform the last water level/idle speed/running condition check and one last air bleed check. If everything checks out = done.


By performing this thourough procedure a cooling system can usually go several months before needing further attention/bleeding.

A timely note for those who are seeing weather changes. At this time of year as the heater valves are turned back on for the first time in many months it is quite common to dump a large amount of air into the system that has accumulated over the summer in the heater cores. This large air pocket trapped for months in the heater cores gets displaced by water and can cause a serious temp rise during the days .

Your Mileage May Vary.

Regards, JRV

 

As per Verell instructions, I transformed the screw on the thermostat housing to have the holes like the one on the radiator. More predictable stream direction and no more dropping of the screw (yes, I did drop it also before).