1992 745 217K

The scent of coolant became evident during last year's heater season but half a bottle of Bar's Leak put it at the back of my Volvo to-do list. This year the smell was accompanied with the defrost setting adding condensation to the windows.

I can not thank the contributors to the FAQ's enough for their submissions. Every bit of support is appreciated in completing the heater core replacement. The extensive photos of the procedure submitted by Ari Rocchio were especially helpful.

I could not justify the $300 Volvo replacement for this particular car. I had a bad experience with a Nissen replacement radiator so I don't use their products. I went with Rock Auto's Spectra Premium ($72). It is not the brass and copper as stated on their site but rather aluminum. There were two problems with fitment:

1. The long dimension is about 5/16" shorter than the original. That required drilling new holes in the back of the heater box so that the steel strap that holds the core in place on the right side can be repositioned- not a huge deal.

2. The inlet and outlet tubes are not parallel to each other. The tubes would initially fit through the opening in the firewall but when I tried to move it into its home position the opening proved to be too small. I had to remove the fender washer immediately below the opening (and eventually the stud as well) and use a die grinder and stone to enlarge the opening. I would guess it required at least 1/8" of firewall to be removed before the core would fit properly and prevent the bottom tube from contacting the firewall. This destroyed what was left of the original foam seal, requiring the opening to be packed and then sealed with silicone.

Having successfully completed the replacement I will share my thoughts and emphasize points made in the FAQ's:

1. I can not even imagine replacing the heater core without removing the seats!

2. Grinding the end of the 7mm socket and then beveling the outside edge gave the socket a better bite on the screws that provided a less than "straight on" approach.

3. I did not need a 1/4" universal for the 7mm socket but I did use strip caulk on the socket connections to help keep them together and also hold the screws in place in the socket.

4. The top center heater box screw that is called out in the FAQ's looked like an impossible task. Reading the FAQ's suggestions in dealing with it provided little comfort.

Working from the passenger's side I took a piece of welding rod and pushed it through the foam that surrounds the opening in the top of the box that houses the heater core. After a couple of repositionings I found a path that put it perpendicular to that pesky top center 7mm screw. I then put together 15" length of 1/4" extensions and carefully pushed the assembly along the same path through the front and back side of the foam that surrounds the connection at the top of the box. The socket easily fit the screw and backed it out with no problem. Upon reassembly I just left that screw out.

I replaced the heater hoses and switched the coolant to G0-5 and distilled water. It also seemed like the opportune time to power wash the carpets after pre-treating them with Spray and Wash. They came out looking great.

Again thanks to everyone who participates in submitting information to Steve as well as his continuing efforts of compiling that information in the FAQ's.

Randy