water pump / heater core

"madness" <u40318@uwe> wrote in message news:7d924a12972ea@uwe...
> Hi, I have a '95 chev silverado 4x4 - I've replaced the radiator (it ran hot,
> overheated, and leaked) I replaced the thermostat and the heater core twice
> (it keeps blowing out). I've never had good heat from the heater in the truck
> and I can sometimes hear the water gurgle back into the overflow jug when I
> shut the truck off. As I said, the heater core blew out again. Could a bad
> water pump cause a heater core to blow out? That would explain the no heat
> issue. Any advice? Thanks.
>
> madness
------


There is and adjustment for the heat flap just behind the dash, and about 1 foot left
of the glove box. Make sure the cable is adjusted as far apart as you can. This will make
sure that the flap that controls airflow over the heater core is fully closed. You also
need to have the proper radiator cap. Yours sounds like its keeping too much
pressure in the system. After you get the right cap, you will need to check the level
each day for about a week. It will take more water over that time as it works out
the air pockets. With the right cap, you should be fine. In case you cant find the
heater core flap adjustment where I said it should be, just follow the cable from the
ac/heater control box (The massive black thing your core is in) to a place where
you can make an adjustment. It might be behind the controls also.

Hope that helps.

HDS
 >> Stay informed about: water pump / heater core 

"Steve W." <csr684NOT.RemoveThis@yahoo.com> wrote in message
news:flehi3$ql4$2@aioe.org...
> madness wrote:
>> Hi, I have a '95 chev silverado 4x4 - I've replaced the radiator (it ran
>> hot,
>> overheated, and leaked) I replaced the thermostat and the heater core
>> twice
>> (it keeps blowing out). I've never had good heat from the heater in the
>> truck
>> and I can sometimes hear the water gurgle back into the overflow jug when
>> I
>> shut the truck off. As I said, the heater core blew out again. Could a
>> bad
>> water pump cause a heater core to blow out? That would explain the no
>> heat
>> issue. Any advice? Thanks.
>>
>> madness
>>
>
> Sounds more like you have a head gasket leak. I would run a pressure test
> on it or run a combustion gas test on it.
>
> --
> Steve W.
> Near Cooperstown, New York

I would second that answer. Not a truck, but a 1990 Pontiac started losing
antifreeze, radiator leaks in several places. My mechanic pressure tested
the system and said the system should show maybe 15 psi max when the engine
was completely up to operation temperature. What happened was after only 3-4
minutes from a cold start it would show 20 psi. It turned out to be pinhole
leak in the head gasket allowing compression to leak into the cooling
system.
 >> Stay informed about: water pump / heater core