How to clean out a heatercore without removing it?

[Rot Box]

My heater is really struggling to put out hot air, and I'm betting that there is a bunch of crap in the cores/fins. Any good tips on how to clean it out while its still in the vehicle? What is the best way to access the dang thing anyway? Thanks!

Andrew

 

[LCAM-01XA]

Pull your glove box/door off. Behind there is a plenum with a large cover held in place by several screws/bolts. Remove that cover, and say hello to your little friend the heater core. Actually from this point removing the core involves simply disconnecting the hoses to it from the engine side of the firewall, and then pulling the core out through the glove box opening. This applies to trucks with factory A/C, not those with the giant "hi-output" core...

 

[OLDBULL8]

You can try back flushing it. Your gonna loose some coolant. Take the hose off the heater the line going to the side of the block first, hold it high, then the one from the pump, stick a garden hose on the heater outlet where you took the first line off. Don't get too wet doing that. You can take a hose from the other heater hose connection and stick it in a bucket to see if any crud comes out. You could partially drain the rad first. Sometimes people put a shutoff valve in the heater input hose?
If you take the core out a radiator shop can boil it out for you.

 

[Rot Box]

Great thanks! I don't think the inside of the core is plugged--I'm betting that there is just a bunch of dirt, lint and other crap in the fins restricting airflow. I'm hoping that's the problem anyway in the past I've always been surprised how much junk gets in these things I'll give it a shot in the morning

 

[crashnzuk]

The core wouldn't be as easy in an 86 would it? Thought I'd ask.
Travis..

 

[Diesel_brad]

The core wouldn't be as easy in an 86 would it? Thought I'd ask.
Travis..

The 86 w A/C is PIE. Not so sure about other years

 

[flareside_thun]

The cores are easy all the way up to 97 for the 250's and up 96 for the Light trucks (ie F150)...after that...FORGET IT. Also, if it's that easy then just pull the thing completely out and flush it......a heater core swap can be done by itself in all of 20 minutes, if that.

 

[brdmh44]

A new heater core can be had for around 30 bucks at autozone. The ease of R&R'ing the core is stupid easy. For the cost it was cheaper to replace the darn thing when my heater wasn't blowing hot air.

 

[LCAM-01XA]

The core wouldn't be as easy in an 86 would it? Thought I'd ask.
Travis..

If truck has factory A/C then it's very easy. If you have no A/C but the hi-output core instead, well it's my understanding it's then that things get interesting - never done one of those tho.

 

[snicklas]

The cores are easy all the way up to 97 for the 250's and up 96 for the Light trucks (ie F150)...after that...FORGET IT.

Agreed, dad has an 97 Light Duty F-250 (the one that looks like a 150 with 7 lug wheels). To replace the Heater Core in the "Tritpn" body trucks, the entire dash has to come out to get to the heater core. They are buried. For a shop to replace the core in one of these I have heard of $500+ to R&R a core.

 

[crashnzuk]

If truck has factory A/C then it's very easy. If you have no A/C but the hi-output core instead, well it's my understanding it's then that things get interesting - never done one of those tho.

Yup, factory a/c. I might give a look-see to make sure it isn't plugged with crap.
Travis..

 

[towcat]

pull the blower motor and you can see is there is crap in there or not.

 

[Csgod0]

I did the heater core on mine last winter, it was super easy. The hardest part was wrapping my head around how to drop the glovebox ( derp). I got an OEM brass replacement, and all in all it took just about an hour's worth of work. Although I did go above and beyond and flush my system of scale before putting my core back in.

speaking of which, i need to check my SCA level

 

[Rot Box]

I've pulled the dash out of a couple cars and they all were a total pita. I was expecting it to be about like that--man I love these trucks! It was really easy

Turns out its really clean and in great shape so I'm wondering if my bypass coolant filter is not letting enough fluid pass through the heater core Either way it isn't getting very warm inside the cab...

 

[SLC97SR5]

Are the heater hoses themselves getting scorching hot?

Is the hot water valve opening all the way?