Het guys first post so sorry if its a little out there.I have a 1998 Blazer with the 4.3 vortec motor.I now have no heat and its overheating.I have checked the oil no water in it and replaced the radiator cap and thermastat both 2 times now as well as a new heater core now.If the water pump was bad would it be flowing at all? i cant get the proper flow maybe air in the cooling system I read.I have tried blowing my heater core out but I think i might not have had enough pressure cause one heater hose still gets hot the other just warm.What and how much pressure is needed to do this correctly?Also why am I having so much trouble burbing the coolant system?any help would be great THANKS IN ADVANCE

 

Sounds like you are not getting all the air out of the system.

 

Buy a flush kit and hook it up to your garden hose. The garden hose will push enough pressure to cycle all the water in your whole system. Squeze your rad hoses with the engine running, you should be able to feel teh water flow through them, also you should see the water flow in the rad if it is a little low on coolant.

 

So is there a certain processI go through to bleed the cooling system?Also would a clogged heater core be reason to overheat?

 

If you put in a new heater core, I highly doubt that it is clogged.

The way I get all of the air out of a cooling system is by elevating the front of the truck with the passenger side slightly higher than the driver side. This will allow the air to migrate to the radiator cap area. With the front end elevated and the radiator cap off, idle the engine until it reaches operating temperature. Then let it cool, topping off the coolant as necessary. Repeat at least one more time. Once you have done this, it should be fairly clear of air. Drive it like you normally do, but check the coolant level daily. You must maintain the level of coolant in the overflow. Too little and you will have problems. Too much, who cares, it'll spill out.

 

THANKS ILL GIVE THAT A TRY

 

What would be symptoms of a bad water pump?I cant figure this out.ITs like the water is not circulating through my system.I tried burbing it but i dont think it worked.Any ideas?I can see the water moving in my radiator but im still not getting results.Any help would be appreciated

 

Hey guys how much difference will 1 pound of pressure make in the cooling system?Talked to the dealership and they said the oem radiator cap is 15 psi all the ones advance sells are 16 how big a difference if any will this make?

 

as far as the overheating i dunno but for the no heat...... did GM still use that crappy quick connect for the heater hoses? like the one that should be on the rear passenger side of the motor? if so you can get a replacement from advance or any auto part store. do not get the one that looks exactly like yours. you will have that same problem later! the one you need will be near the rad caps in advance. it is like a stainless color. you will need to remove your old one and replace it with that. now before you say "bz, how does that nipple connect to my trucks nipple?" het a small peice of heater gose and 2 hose clamps.
thats my 2cents