Easiet way to change heater core '87 GT
01-08-2005, 05:19 PM
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RE: Easiet way to change heater core '87 GT
The most recent heater core job that I did was in my '90 LX 5.0 5 speed when it hit 66K miles last February. I did the whole job with the A/C completely connected!
The trick to it is to get everything loosened up, and REMOVE the bracket off of the A/C accumulator (engine_c.jpg). This will allow enough freedom to get the evaporator case away from the firewall about one inch. It's very difficult and a royal pain, but you'll need to remove the two 5/16 self-tapping screws that hold the core cover in place. I used an small ignition wrench to remove the screws. With everything loose and the dash propped up (drvrs_v.jpg) and away from the windshield, you can open the core cover and remove the old core (removal.jpg). Removing the old core without damaging it is a good test to determine if you can install the new core without damaging it, so keep that in mind. It is crucial in this procedure to prop the core cover and the dash up out of the way so you can work (detail_1.jpg). I used a large socket and a 1/2 drive extension (detail_2.jpg) to hold the cover open (dashview.jpg) to extract the old core and install the new one without tweaking it (very important.) Before installing the new core, I painstakingly cleaned, with surgical precision, the old black goo sealant that seated the old core (install.jpg). By far, the most difficult task of the entire job is getting the new core's tubes lined up with the gasket and holes in the firewall. On my car this step took the longest of any single step in the entire job. But don't despair, get a helper and with one person maneuvering the case on the inside and one person on the outside steering the lines to their propper place, you will get it, it just takes time!
How do you make the flow restrictors? I made them from 5/8 OD aluminum stand-offs drilled to 0.25" ID (restrict.jpg). The heater seems to be effective but the motor has to be good and hot for the heater to be _really_ hot. I can live with this, but if I were to do it again, I might consider a 3/8 ID. After about 20 minutes of normal driving, I observed air temperature of 157F. This is with a 192F thermostat. When installing the heater core restrictor, make sure that it goes in the input or pressure side. The input/pressure side is the top metal tube that runs along the intake and the larger of the two pipes on the heater core.
The trick to it is to get everything loosened up, and REMOVE the bracket off of the A/C accumulator (engine_c.jpg). This will allow enough freedom to get the evaporator case away from the firewall about one inch. It's very difficult and a royal pain, but you'll need to remove the two 5/16 self-tapping screws that hold the core cover in place. I used an small ignition wrench to remove the screws. With everything loose and the dash propped up (drvrs_v.jpg) and away from the windshield, you can open the core cover and remove the old core (removal.jpg). Removing the old core without damaging it is a good test to determine if you can install the new core without damaging it, so keep that in mind. It is crucial in this procedure to prop the core cover and the dash up out of the way so you can work (detail_1.jpg). I used a large socket and a 1/2 drive extension (detail_2.jpg) to hold the cover open (dashview.jpg) to extract the old core and install the new one without tweaking it (very important.) Before installing the new core, I painstakingly cleaned, with surgical precision, the old black goo sealant that seated the old core (install.jpg). By far, the most difficult task of the entire job is getting the new core's tubes lined up with the gasket and holes in the firewall. On my car this step took the longest of any single step in the entire job. But don't despair, get a helper and with one person maneuvering the case on the inside and one person on the outside steering the lines to their propper place, you will get it, it just takes time!
How do you make the flow restrictors? I made them from 5/8 OD aluminum stand-offs drilled to 0.25" ID (restrict.jpg). The heater seems to be effective but the motor has to be good and hot for the heater to be _really_ hot. I can live with this, but if I were to do it again, I might consider a 3/8 ID. After about 20 minutes of normal driving, I observed air temperature of 157F. This is with a 192F thermostat. When installing the heater core restrictor, make sure that it goes in the input or pressure side. The input/pressure side is the top metal tube that runs along the intake and the larger of the two pipes on the heater core.
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10-04-2015 10:15 AM
1987, 1993, 87, change, coil, convertible, core, easy, gt, heater, heatercore, mustang, removing, replace, replacement
