Heater Core Question
12-19-2015, 12:02 AM
#31
CF Veteran
Thread Starter
Join Date: Nov 2011
Location: Northern MN
Posts: 2,433
Likes: 0
Received 6 Likes
on
5 Posts
Year: 1990
Model: Cherokee (XJ)
Engine: Renix 4.0
AC is evacuated, and I was told the system had already been converted to R134a. I'll be bundled up like Ralphy for my drive home tomorrow 
12-19-2015, 10:04 PM
#32
CF Veteran
Thread Starter
Join Date: Nov 2011
Location: Northern MN
Posts: 2,433
Likes: 0
Received 6 Likes
on
5 Posts
Year: 1990
Model: Cherokee (XJ)
Engine: Renix 4.0
This job is kickin my ***. Two of the studs for the box support are turning with the nuts. The upper dash bolts are under the dash vents which have one screw that I can just barely get to. I'm glad I have the next couple days off...
12-20-2015, 07:18 AM
#33
::CF Moderator::
Join Date: Aug 2011
Location: Prescott, Az
Posts: 43,971
Received 1,559 Likes
on
1,263 Posts
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
There is only need to remove ONE dash attaching fastener.
12-20-2015, 02:22 PM
#34
CF Veteran
Turn to nuts backward and the stude will unscrew from the box. When the box is removed you can get at the studs from the inside.
12-20-2015, 02:36 PM
#35
CF Veteran
Thread Starter
Join Date: Nov 2011
Location: Northern MN
Posts: 2,433
Likes: 0
Received 6 Likes
on
5 Posts
Year: 1990
Model: Cherokee (XJ)
Engine: Renix 4.0
Thanks, Cruiser. I owe you countless IPAs for all the help over the years. I have the core replaced, and the box is propped up waiting to be secured. I needed a snack break lol I'll have it back together in another hour or two.
12-20-2015, 04:11 PM
#36
Newbie
Join Date: Aug 2012
Location: Michigan
Posts: 17
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
a friend and I replaced his heater core and ac evaporator in about 3 hours never having done this before. I think saying it takes a weekend is a bit much. we even disassembled and cleaned the hvac box. it's really not a terrible job. we dropped the steering column and swung the entire dash out of the way enough to pull the box.
op: you might consider changing the ac evap too since you'll be in there.
op: you might consider changing the ac evap too since you'll be in there.
You discovered the leak while changing the coolant so it was likely already there and you just had opportunity to spot it. Use spec premix antifreeze or mix your own 50/50, use distilled water only. That should help to slow such corrosion.
** Note: The actual optimal mix is 49/51 but I do not remember which was water and which was antifreeze. Been 35 yrs since mechanic school!
Also you can of course bypass the heater core if you wish to go without heat. Use a couple hose clamps and anything that fits properly in the hose. Pipe, pvc, a old socket, whatever so long as it's temporary in some cases.
Thread
Thread Starter
Forum
Replies
Last Post
seductivepillowcase
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
9
12-10-2015 09:27 AM
george86
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
6
12-03-2015 02:29 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)