So after reading up on several of the heater core threads, I decided I'd undertake this procedure to try and make the heat being generated from my heater a little hotter.
Prior to this procedure, it was running about 95° from the front and rear heaters of my 1986 FJ60.
Thanks to all of those that posted and helped in the other threads.
NOTE: Due to the difference in hoses that have been used to replace the original hoses on your rig, as well as other changes that may have occurred, I recommend you confirm your setup before diving into this.
Materials needed:
1 gallon of muriatic acid
Replacement screw clamps
Extra coolant
clear flexible hose (approximately 3 feet), I think I got 1.25" hose
Bucket
Funnel
Flat head screwdriver
Air compressor (optional) or bike tire pump
Steps:
1. The hose pointing up in the picture below is what you want to disconnect to feed the acid into the core. The hose below that, you will disconnect to drain out the coolant and acid. Facing from the front, these are on the firewall just to the left of my engine.
2. Remove the retaining pin and pull down the hose on the upper hose, then unscrew the screw hose clamp on the lower hose as indicated in the picture below.
3. At this point, attach the clear hose to the metal host insert and drop the lower end into your bucket under your rig. Initially, this will drain some coolant, then you'll blow even more out with your compressor or pump.
Here are a couple of pictures of this:
I stuffed a blue shop paper towel in the removed hose so coolant wouldn't drip out in case you were wondering what that is.
4. At this point, put your funnel in the top hose and start pouring acid into it. Pour a little at a time so you can make sure it doesn't get everywhere since it is pretty reactive. You'll start to see or hear some bubbling coming from the outlet hose and it may start displacing brown liquid, which means it's working and removing deposits from the heater core.
I have seen a post where someone had to park uphill to get the core filled, but mine was only on a slight incline so I don't know if this will make a huge difference. If you get done with this process and don't notice an increase in the temp blowing out, try it again on a hill, with the front of your rig pointing uphill.
5. Once you have filled up the core and the liquid coming out is clear, it's time to drain it out. I had to tape my air compressor hose nozzle to the top of the hose (take the funnel out of course) so that acid didn't spray everywhere. Go lightly on the pressure and it should flush all of this out. I would recomment flushing with water, then add half and half water/coolant back into the top hose.
6. After that started to come out the bottom hose, I attached both hoses with new screw hose clamps, rinsed everything off and started the engine.
Depending on your results you may also want to park on an incline to burp the core of any air. You should only need to detach the upper hose to get this done.
My temps are now a good bit hotter. I don't know the exact temperature, but for the first time, I've actually had to turn the heat down.
One other thing that could have an impact with heating is the thermostat. I changed mine before attmpting this procedure and although I didn't see an increase in the temps, I did start getting warm air sooner (5 minutes as opposed to 20).
I did not do this procedure for the rear heater, but if anyone wants to post steps for this with pics, I'll be glad to add it.
Try this and let me know if you have any questions!
Winston
Prior to this procedure, it was running about 95° from the front and rear heaters of my 1986 FJ60.
Thanks to all of those that posted and helped in the other threads.
NOTE: Due to the difference in hoses that have been used to replace the original hoses on your rig, as well as other changes that may have occurred, I recommend you confirm your setup before diving into this.
Materials needed:
1 gallon of muriatic acid
Replacement screw clamps
Extra coolant
clear flexible hose (approximately 3 feet), I think I got 1.25" hose
Bucket
Funnel
Flat head screwdriver
Air compressor (optional) or bike tire pump
Steps:
1. The hose pointing up in the picture below is what you want to disconnect to feed the acid into the core. The hose below that, you will disconnect to drain out the coolant and acid. Facing from the front, these are on the firewall just to the left of my engine.
2. Remove the retaining pin and pull down the hose on the upper hose, then unscrew the screw hose clamp on the lower hose as indicated in the picture below.
3. At this point, attach the clear hose to the metal host insert and drop the lower end into your bucket under your rig. Initially, this will drain some coolant, then you'll blow even more out with your compressor or pump.
Here are a couple of pictures of this:
I stuffed a blue shop paper towel in the removed hose so coolant wouldn't drip out in case you were wondering what that is.
4. At this point, put your funnel in the top hose and start pouring acid into it. Pour a little at a time so you can make sure it doesn't get everywhere since it is pretty reactive. You'll start to see or hear some bubbling coming from the outlet hose and it may start displacing brown liquid, which means it's working and removing deposits from the heater core.
I have seen a post where someone had to park uphill to get the core filled, but mine was only on a slight incline so I don't know if this will make a huge difference. If you get done with this process and don't notice an increase in the temp blowing out, try it again on a hill, with the front of your rig pointing uphill.
5. Once you have filled up the core and the liquid coming out is clear, it's time to drain it out. I had to tape my air compressor hose nozzle to the top of the hose (take the funnel out of course) so that acid didn't spray everywhere. Go lightly on the pressure and it should flush all of this out. I would recomment flushing with water, then add half and half water/coolant back into the top hose.
6. After that started to come out the bottom hose, I attached both hoses with new screw hose clamps, rinsed everything off and started the engine.
Depending on your results you may also want to park on an incline to burp the core of any air. You should only need to detach the upper hose to get this done.
My temps are now a good bit hotter. I don't know the exact temperature, but for the first time, I've actually had to turn the heat down.
One other thing that could have an impact with heating is the thermostat. I changed mine before attmpting this procedure and although I didn't see an increase in the temps, I did start getting warm air sooner (5 minutes as opposed to 20).
I did not do this procedure for the rear heater, but if anyone wants to post steps for this with pics, I'll be glad to add it.
Try this and let me know if you have any questions!
Winston
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