'91 Jetta 1.6D Not Building Coolant Pressure

[Renax]

Does not build pressure, does not boil, does not lose any coolant? Well then, what's the problem?

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[92EcoDiesel Jetta]

Alright....So I replaced the head gasket (the car head a mechanical head on a hydraulic block) and cylinder head with the correct hydraulic. STILL does not build any cooling system pressure.  My commute home is mostly uphill, 24-26 miles, and it does not heat up.  Both upper and lower radiator hoses are hot.  Thermo opens when it should.  The car does NOT run hot while running.  It hasn't been too hot since the head and HG replacement so there have been no coolant loss like before, through the puke hole in the coolant reservoir.
It just will NOT build pressure.

Also, since my last post, I have replaced the coolant reservoir bottle AND bought another reservoir cap in case the previous brand new one was faulty.
I'm at a loss.  New rebuilt (correct) head, new HG and new bolts.

I'm open to any ideas a this point.

Did you do a coolant system  pressure test? You must have a leak somewhere.

[damac]

I'm not buying the no pressure thing, where are you getting this from without hooking a tester to measure psi?

If both hoses are warm and you are running it fully warm and not losing coolant how are you not going to have pressure one way or the other?

I don't see where you mentioned that you have the correct thermostat for your car and verified with a thermo on the stove that it operates correctly?

Also what is your fan doing during all of this?  I don't have one car that will not eventually cycle the fan idling on the driveway.

And how are you verifying actual temps.  I don't trust vw stock gages only because I have seen goofy readings on all gages when voltage controller/ground/power gets flaky.

[mtrans]

Put "T" in small pipe and with compressed air put 0.3 bar and see if lose press.

[CODE4LS1]

The fan cycles on and off as it should.  It can sit in my driveway and idle all day and never boil over. Until I shut it off, then coolant level rises up the reservoir and out the puke hole, due to no pressure keeping the boiling point at bay.

I can squeeze both upper/lower hoses while running, after a hard drive, after climbing a hill, etc., and hoses will remain soft.  It will not overheat while running.
I already verified t stat opening/closing as it should.

I have not performed a cooling system pressure test.  I haven't brought myself to pay for the adapter I need.
That is the only thing left to test, so I suppose I'll get it ordered, perform the test and report back.

[theman53]

Heat soak after the engine is shut off causes the coolant to expand.  I'm assuming because of heat expansion, the coolant level rises up and out of the overfill hole in the reservoir bottle, as there is no pressure to prevent this.
I have already verified proper operation of the thermostat.  The car does NOT overheat at all while it's running. Completely normal.  I have also verified coolant circulation.  As far as I can tell anyway, every aspect of the cooling system operation is normal, save for no pressure.
I even looked to local parts stores for a cooling system pressure tester, but the ones they have do not work on the VWs.

what do you mean by "overfill hole in the reservoir bottle."

This is a different system...we have no puke hole. Pics as I think you have this messed up.