Jump to content
Ultimate Subaru Message Board

Heater Core Back flush


Recommended Posts

Is it posible to back flush the heater core from under the hood of the car? Would I need some extra hoses and or connecters to do so? I looked at the Heater core replacement link and I would like to just try back flushing it first is I can.

 

Other questions are: Can the heater control (the one that goes from Cool to Hot) just have a loose cable on it and if so how do you tighten it so that when you turn it to hot the cable is tight? Do you have to take apart the radio and dash to fix this as well?

 

Just trying the cheapest method first, I can't do the work myself, so I will have to have someone do these for me.

 

Thanks for any help.

Link to comment
Share on other sites

You shore can...

I always install flush tee's on both the inlet and outlet hoses. Then you can clamp down the hoses to prevent water flow, and in doing so, can flush your cooling system out any combination of ways. I use Prestone Super Flush to break things up first.

The heater control linkage is probably binding somewhere. You will have to remove some trim to have better access to the linkage system.

good luck, John

Link to comment
Share on other sites

Lefty, are you considering doing this because you have kind of a sissy heater?

 

Let me know if it helps with your heater, Ive been contemplating doing the same but dont want to spend the extra $$ if its not going to do anything.

 

Thanks

Link to comment
Share on other sites

Thanks John, never thought about putting in a T for that purpose. I did take out the left side dash part and a couple of other pieces that allowed me to see the linkage to the heater control. Looked like it was in good shape, and tried to open the Water Cock farther, but it seemed to be open all the way after turning the Heater Control from Cold to hot. Must be the core itself. The car only has 137,000 miles on it but I guess that is enough to clog the core if it didn't have good coolent in it.

Link to comment
Share on other sites

Cores usually hold up better than radiators over time, and at 137k, the flush may do the trick.

One exception is when "Cooling Stop Leak" products are used. This can clog up the core beyond salvation. Hopefully, this is not the case.

When you run water thru the core, you'll want increase water pressure gradually so you wont burst the core. You'll know pretty quickly during the backflush the condition of the core by the color of the fluid that comes out. Keep running water throughout the whole system till it runs clear.

 

good luck, John

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...