errrr..this conflicts with the advice given on sure
Tests for the Cooling System
                                  TEST #2
                                  DO'S  &  DON'TS  FOR
head REMOVAL
                                  WORDS TO THE WISE
                                  PARTS NEEDED TO
REASSEMBLE
                                  PARTS # list
                                  PARTS: HARDWARE
                                  TIME TO REASSEMBLE
                                  PUSH RODS
                                  BLEEDING THE COOliNG
SYSTEM
                                  THE LAST DETAILS
                                  TOOLS NEEDED FOR
head REPLACEMENT
                                  FINAL NOTES

                              So you're thinking its
time
                             to replace the heads on
your
                             water boxer, and you're
                             asking yourself  if you
can
                             do a job like this.  Can
this
                             be done on the ground
                             without a lift?   I will
try to
                             help you answer these
                             questions.  First, lets
go over
                             the most common reasons
to
                             remove the cylinder
heads.
                             Make sure to be clear
about
                             what's leaking before you
                             begin the job. It can be
oil or
                             coolant that's dripping
from
                             the heads.

Washing the engine is very

helpful when looking for leaks.

If the push rod tubes are

leaking or if a lifter has

collapsed, you can use an

expanding push rod tube,

which is available at the dealer

for  $50 each, or in the

aftermarket for about half of

that.

The most common coolant

leak is from a cracking or

splitting rubber outer coolant

gasket at the head.

Often this will be accompanied

by a corrosive reaction where

                        the rubber gasket contacts the

                       head.  Unfortunately, there is

                       no easy way out of this repair.

                       The heads must be removed to

                       replace these gaskets, and at

                       this time a close inspection of

                       the heads will indicate the

                       extent of corrosion. A

                       corroded head will not make

                       the best possible seal with the

                       gasket.

                        Another reason the heads may

                       need to be removed is

                       pressure build up in the
cooling

                       system.

                             This is do to the head
gasket at
                             the top of the cylinder
leaking
                             compression when the
engine
                             is cold.

                             TEST #1: Pressure Tests
                             for the Cooling System

                              The first test of the
cooling
                             system is done when the
engine
                             is cold.  A cooling
system
                             pressure tester can be
installed
                             in place of the radiator
cap.
                             Pressure in the cooling
system
                             and hot coolant are not
                             something to be treated
lightly.
                             Use caution, and never

remove the radiator cap from

a engine  that has been run

even for even a short time.

After installing the gauge,

pump it up to 10 pounds.

Look around for leaks if the

gauge shows any pressure

loss.

Common trouble spots

include heads, hoses, water

pump and rear heater core. If

you smell something sweet

when you turn the heater fans

on, it may be a coolant leak

at one of the heater cores, or

simply the O-ring at the rear

heater

                        valve leaking. Because there
is

                        often more then one leak in

                        the system, it is necessary to

                        continue pressure testing
until

                        the system holds pressure.

                        TEST #2

                          Start the engine cold with
no

                        pressure indicated on the

                        gauge.  The pressure in the

                        cooling system builds to aprox

                        7 lbs at normal running temps

                        looking around for leaks. But

                        if the pressure builds quickly

                        to around 15 lbs the pressure

                        is coming from one of the

                        cylinders

from 'boston engines' ...???

Steve

--- Rico Sapolich <JKrevnov@AOL.COM> wrote:
> In a message dated 3/14/00 11:52:23 PM,
> sdelasal@YAHOO.COM writes:
>
> << I've asked for a cooling system pressure check on
> a water cooled van that
> I'm considering to see if there's
>
> any evidence of leaking cylinder heads - is this a
> good idea?, What is a
> reasonable pressure to expect?
>
> any better ideas?   >>
>
> Steve:
> Damn good idea!  It can expose a myriad of sins.  15
> psi is called for.  I
> would check it cold AND after it has reached
> operating temperature.  I have
> seen hydronic systems test out good cold then, once
> up to operating
> temperature, it is time to get out the umbrellas.
> Although, Vanagons
> sometimes seem to show their weaknesses more after
> they cool down.
> Rich
>

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