Thanks, Frank.

i might have a head set for this

What is your definition of moderate? I'd say moderate boost would be around 20psi and I would never do that with a composite.

We have a difference in opinion of modest. Mine is around 10-12 psi. I'd call high boost pressure at 18-20 psi, silly boost is about 26-28 and after that I call it stupid boost.

I guess I think of water and alcohol for drinking.

Frank

Life begins @ 2bar!!

Well...

I got lazy and dropped the truck off this morning at a radiator specialist. He drove it, couldn;t find any issues, drove it some more, still no issues. Took it back to the shop and did a pressure test, no leaks, checked the oil, didnt look like there was coolant in it. He said the problem must have been an AIR BLOCKAGE in the cooling system. I said what about the high level of coolant consumption? He said it could be head gasket related, but the regular coolant system pressure test would likely not show that. He said to monitor the consumption carefully, and if it is increasing, let him know. So how does an ai bubble or blockage happen? Would it have happened when I changed the blown hose? Was I supposed to bleed the cooling system after I changed the hose?

So I feel better now, and can now take my truck into the backroads of BC this weekend and do some exploring!

Yeah it could happen when you replaced the hose. I would still recommend a compression test though.

Here is a nifty tool that I like to use to eliminate air bubbles.

Bleed it? No. Burp it? Yes. Gen1s are fairly susceptible to air bubbles in the cooling system, but I haven't heard of one losing coolant because of it. I suppose it's possible that any air in the system could result in a steam buildup which would drive out coolant and the more coolant lost, the worse the steam issue and so on. Steam could cause the upper radiator hose to become tight, but my question would be what caused the heater hose to rupture? Possibly only old age, but possibly the pressure was already there before you started making steam. Dunno.

I certainly would continue to watch the coolant level.

The best way I've found to "burp" the Gen1 coolant system is to fill it, open the heater controls, warm up the engine and drive it over the roughest road you can find.... potholes are your friend. Take it hard into a few corners (preferably rough ones), bump a curb or two and do some jackrabbit starts and some panic stops. That should take care of any air bubbles. <img src="/forums/images/graemlins/wink.gif" alt="" />

Frank

Just for future search reference, MLS headgaskets require an RA of 15-30. Find a machine shop that can do that. If they don't know what you are talking about then find a different one!

Yes, I know what they require - but sometimes finding a local shop that can do it is another matter. And saying what finish can be achieved and actually achieving it are two different things. I don't have the equipment to measure finishes, but I do have a decent eyball and the last shop I used for the Galant head that went on the MM looked to me like it was a good enough finish for a MLS gasket. At the boost level I'll put on the next blower engine, composite gaskets should work fine - although I will be running a little more dynamic compression this time.... so if I have problems, I might try the MLS gaskets again.

Thanks -

Frank