Heater core backflush w/ pics - AudiWorld Forums

Go Back  AudiWorld Forums > Audi Models > Audi A4 > A4 (B5 Platform) Discussion
Reload this Page > Heater core backflush w/ pics
Notices
A4 (B5 Platform) Discussion Discussion forum for the B5 Audi A4 produced from 1995-2001 B5 FAQ
Sponsored by:
Sponsored by:

Heater core backflush w/ pics

Reply

 
 
Old 11-30-2008, 07:41 PM
  #1
AudiWorld Super User
Thread Starter
 
Join Date: May 2001
Posts: 12,236
Default Heater core backflush w/ pics

After being without heat since early spring, I decided it was time to set things right. Using <a href="https://forums.audiworld.com/a4/msgs/2777788.phtml">this post</a> as a guide, I went to Home Depot and bought 10' of 3/4" id tubing to make my life easier. As I later discovered, 7/8" would have been much easier to work with.

Remove the rear firewall rubber gasket, cover, and plastic tray/pollen filter and passenger side windshield cover. Get the wiper arms vertical. The engine bay should now look like this:

<img src="http://pictureposter.audiworld.com/20538/heater_core_backflush1.jpg">


Wedge the driver side wiper cover up on top of the wipers to get it out of the way. Remove the corrugated hose cover (it's split on the back) to expose the lines running into and out from the heater core. You should now be looking at this:

<img src="http://pictureposter.audiworld.com/20538/heater_core_backflush2.jpg">


Slide your tubing over the inlet side and run the other end down to a bucket of some sort. You'll need 4-5'.

<img src="http://pictureposter.audiworld.com/20538/heater_core_backflush3.jpg">

<img src="http://pictureposter.audiworld.com/20538/heater_core_backflush4.jpg">


Slide a shorter length of tubing over the outlet side (1-2'). I used a brass hose nozzle that increases flow as you twist it because it sealed fairly well against the end of the hose. Turn on the water flow (not too hard as the heater core is a bitch to replace) and watch the gunk come out. Keep flushing until the water coming out is clear.

Reverse the hose and forward flush, again making sure the water coming out is clear. Now is probably a good time to drain, flush, and bleed your whole cooling system. Reverse the removal steps to get things back together. Here's what I was left with:

<img src="http://pictureposter.audiworld.com/20538/heater_core_backflush5.jpg">

...oh yeah, and <b><font color="red">HEAT</font></b>.
TristanP is offline  
Reply With Quote
Old 11-30-2008, 08:31 PM
  #2
AudiWorld Super User
 
Join Date: Mar 2004
Posts: 11,955
Default Did the same last week except without all the hoses... just undid one of the hoses on the

client's 2002 A4 and let it flush for 10 minutes on the driveway... now she has heat again as well :-)
Roger @ CA is offline  
Reply With Quote
Old 12-01-2008, 04:08 AM
  #3
Banned
 
Join Date: Mar 2000
Posts: 34,549
Default

nice!
ModifiedA4 is offline  
Reply With Quote
Old 12-01-2008, 08:12 AM
  #4
AudiWorld Member
 
Join Date: May 2004
Posts: 524
Default

I need to do the same, but whats the risk of causing a leak in the heater core?
djdc is offline  
Reply With Quote
Old 12-01-2008, 09:10 AM
  #5
AudiWorld Super User
 
Join Date: Mar 2004
Posts: 11,955
Default

Heater core is inside the car... 8 hours later you can swap it out, after taking dash out :-)
Roger @ CA is offline  
Reply With Quote
Old 12-01-2008, 09:29 AM
  #6
AudiWorld Super User
Thread Starter
 
Join Date: May 2001
Posts: 12,236
Default Like Roger said

<a href="https://forums.audiworld.com/a4/msgs/2863079.phtml">Kris did his</a> and it ain't a pretty picture.
TristanP is offline  
Reply With Quote
Old 12-01-2008, 09:35 AM
  #7
Banned
 
Join Date: Mar 2000
Posts: 34,549
Default question...

was the coolant in the resevoir tank the same color as the 'gunk'?
ModifiedA4 is offline  
Reply With Quote
Old 12-01-2008, 10:43 AM
  #8
AudiWorld Super User
Thread Starter
 
Join Date: May 2001
Posts: 12,236
Default Yes, I still need to replace the radiator

Flushing it out produced more of the same. Maybe I'll get to that this winter in my new garage. For the moment, I can live with it. Gotta stay warm.
TristanP is offline  
Reply With Quote
Old 12-01-2008, 11:42 AM
  #9
Banned
 
Join Date: Mar 2000
Posts: 34,549
Default ok...

so its safe to assume if your resevoir looks like virgin G12, flushing the heater core might not be needed.
ModifiedA4 is offline  
Reply With Quote
Old 12-01-2008, 12:34 PM
  #10
AudiWorld Super User
 
Join Date: Mar 2001
Posts: 5,244
Default

Thats what I'm thinking as well. I got no heat but my resevoir coolant looks OK.
velo is offline  
Reply With Quote
 
 
 

Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
SimianSpeedster
TT (Mk3) Discussion
61
08-09-2016 10:16 AM
SimianSpeedster
TT (Mk3) Discussion
15
03-29-2016 09:13 PM
akitamike
Vehicles For Sale
3
09-05-2015 03:01 PM
Audi Junkie
A4 (B5 Platform) Discussion
11
12-16-2005 06:22 AM
AG Fours
A4 (B5 Platform) Discussion
3
04-07-2000 05:25 PM


Thread Tools
Search this Thread
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -8. The time now is 01:21 AM.


 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: