Coolant Gushing Out...

[jrp27540]

So I just changed the heater core in my 88 LX. After letting it warm up, coolant is gushing out into the overflow container. Figured there may be air in the lines, so I pulled of the radiator cap. Let it run for a bit and coolant started gushing out of the radiator cap. I'm not sure what's going on. I turned the heat to hot, but no hot air is coming out. Is there just a punch of air in the system and just needs a good flush?

 

[stykthyn]

Sounds like it. Jack up the front of the car so that the radiator cap is the highest point. Let the engine run until the Tstat opens. This should allow any trapped air to escape.

 

[mikestang63]

get a lisle funnel and burp all the air out of the system. Make sure the heater is on max and hot.. No need to jack the car up with the funnel. best $25 you will spend.

 

[stykthyn]

get a lisle funnel and burp all the air out of the system. Make sure the heater is on max and hot.. No need to jack the car up with the funnel. best $25 you will spend.

I still need to buy one of those

 

[jrp27540]

get a lisle funnel and burp all the air out of the system. Make sure the heater is on max and hot.. No need to jack the car up with the funnel. best $25 you will spend.

So this begs another question. The previous owner deleted the A/C. I have a strong feeling the vacuum system for the heating/cooling system. The air only blows out the defroster only; I cant get it to change locations. The cold/hot switch is also hard to turn. I can see the blend door cable moving behind the glove box when I change the heat, but im not sure its doing anything inside the box... Im concerned that I cant get the "heater at max hot" if its not working properly. Is there a vacuum diagram out there for the cooling/heating system? I have been looking around with no luck. Im guessing the vacuum line to change the location is missing.... It looks like its there under the dash, but I know there is a location under the hood that a vacuum line comes to for that control.

Thanks for all the help!

 

[jrichker]

The following are diagrams courtesy of Tmoss & Stang&2birds

HVAC vacuum diagram

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring; http://www.veryuseful.com/mustang/tech/engine/ Everyone should bookmark this site.

94-95 Mustang wiring diagrams
http://www.veryuseful.com/mustang/tech/engine/#95-95Diagrams

Complete computer, actuator & sensor wiring diagram for 91-93 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

O2 sensor wiring harness
http://www.veryuseful.com/mustang/tech/engine/images/mustangO2Harness.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif

TFI module differences & pin out
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif

Fuse box layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

Mustang 5.0 Lights and Radio schematic, by TMoss:
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxLights-Radio_diag.gif

87-92 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang87-92 PowerWindowWiring.gif

93 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang93PowerWindows.gif

T5 Cutaway showing T5 internal parts
http://www.veryuseful.com/mustang/tech/engine/images/5_Speed_Cutaway_Illustrated.jpg

Visual comparison of the Ford Fuel Injectors, picture by TMoss:
http://www.veryuseful.com/mustang/tech/engine/images/Ford_Injector_Guide.jpg

Convertible top motor wiring http://www.veryuseful.com/mustang/tech/engine/images/mustang88VertTopMotorCkt.gif

Engine mounted fuel injector harness
http://www.veryuseful.com/mustang/tech/engine/images/mustangEngineHarness.gif

Location of the TPS, IAB, and the 10-pin connectors on a 5.0, picture by TMoss:
http://www.veryuseful.com/mustang/tech/engine/images/TPS_IAB_Pic.jpg

Starter circuit
http://forums.stangnet.com/attachment.php?attachmentid=21328&d=1080916057

 

[LiquidStangs]

The air only blows out the defroster only; I cant get it to change locations.

Same thing happened to me. It turned out to be the vacuum line running from the vacuum tree to a connector on the passenger side, running across the bay right by the firewall. Mine was originally this thin plastic thing which was brittle after all these years. Replaced it with real vacuum line, and the different settings now work.

 

[jrp27540]

Same thing happened to me. It turned out to be the vacuum line running from the vacuum tree to a connector on the passenger side, running across the bay right by the firewall. Mine was originally this thin plastic thing which was brittle after all these years. Replaced it with real vacuum line, and the different settings now work.

Yes, I believe this is my issue as well considering he just put a cap on the vacuum tree for the A/C, which I think controls the location of the air being blown. I see the vacuum tree connector on the passenger side...but no vacuum line running to it from the vacuum tree. Going to get some vacuum line tonight and hook it back up.

 

[jrp27540]

Just to follow this up. I got a lisle funnel and was able to burp all the air out of the system. The heater is working as expected now. I haven't had a chance to get the air to change vent locations, but im 100% positive its due to the missing vacuum line. Ill try to get it going this weekend. Thanks for the help everyone!