Can't Get Air Out of Heater Core / Considering Vacuum Kit

The Fourth Amigo

Well-known member
Apr 20, 2009
641
2
Any advice on getting air out of the heater core? I've read lots on the subject but can't get it done. No loss of coolant overheating etc., just sloshing noise.

Anyone recommend a vacuum bleed/fill tool that will work with a DII?
 

discostew

Well-known member
Sep 14, 2010
7,706
1,015
Northern Illinois
Leave the cap off the reservoir until you have a steady stream from the small return port that is near the opening in the reservoir. It can't bleed itself with the cap on. If you have a steady stream from that port and have to bleed it again in a week or so, you might have a headgasket problem.
 

The Fourth Amigo

Well-known member
Apr 20, 2009
641
2
I have a steady stream from the small port. The problem started after I replaced the heater plate gasket last week. I remember, maybe 5 years ago, I had the same problem and just lived with it. It went away after I did some other job which required coolant filling. I guess I got lucky.
 

discostew

Well-known member
Sep 14, 2010
7,706
1,015
Northern Illinois
I would tell you to lift the reservoir off its mounts to get it higher than the heater core, but its not worth the risk if breaking one of those plastic pipes. Keep driving it.
 

The Fourth Amigo

Well-known member
Apr 20, 2009
641
2
I've lifted the reservoir and tried the vent screw, no air. I've driven around with the cap off, etc. Still get the annoying sound. I haven't tried it with the front end elevated, yet. I've drained the coolant many times on this vehicle during the 10 years I've owned it and this happened in the past. Sometimes I can get it corrected sometimes not.
 

luckyjoe

Well-known member
Oct 10, 2004
455
118
New Jersey USA
I have a long funnel, that I thread into the top radiator bleed port. It's about 20 inches tall and I fill it with coolant then let the engine idle through several t-stat open/close cycles. This always does the trick for me. However, at one point I remember the dealers were swapping the heater inlet/outlet hoses on D1's to reduce sloshing sounds - don't know if this would help on a D2 or not...
 

Lake_Bueller

Well-known member
Aug 11, 2004
2,105
59
56
Beloit, WI
I'm having the same problem after an engine swap. Not losing any coolant and the engine temp is solid. I had heat the first few days. Then it got worse and worse until now I have no heat.
 

4Runner

Well-known member
May 24, 2007
660
110
Boise Idaho
I have never had a DII but driving mine onto a pile of dirt to raise the front end way up has always worked for me. Besides it’s fun.
 

The Fourth Amigo

Well-known member
Apr 20, 2009
641
2
I have a long funnel, that I thread into the top radiator bleed port. It's about 20 inches tall and I fill it with coolant then let the engine idle through several t-stat open/close cycles. This always does the trick for me. However, at one point I remember the dealers were swapping the heater inlet/outlet hoses on D1's to reduce sloshing sounds - don't know if this would help on a D2 or not...

Both sound like reasonably good ideas.

I have ordered a vacuum filling tool that a friend of mine who is a professional mechanic recommended. I'll let you know if it works out.
 

gthphotography

Well-known member
Aug 27, 2008
317
3
chicago
www.greghanrahan.com
the issue stems from the horrible fact that the high point in teh D2 cooling system is in teh dashboard. What I do, and it has always worked for me is I jack the front of the truck up as high as I can and then pop the expansion tank out of its holder and raise it up as far as I can get it (this is usually above the high point in the dash adn then fill). Then, just to make sure, there is a parking lot by my place with a really steep hill. Ill drive onto the inclace, park the truck and then top off. Works every time.
 

luckyjoe

Well-known member
Oct 10, 2004
455
118
New Jersey USA
I use something like this. You can slowly work it into the radiator’s top fill plug on a D1/RRC, effectively tapping the plastic tip. Once you do this it will stand on it’s own without leaking, raising the coolant level about 15-17 inches.

c837ea8d-07a2-49e3-84af-0610d6235ec9.jpg
 

kk88rrc

Well-known member
I use something like this. You can slowly work it into the radiator?s top fill plug on a D1/RRC, effectively tapping the plastic tip. Once you do this it will stand on it?s own without leaking, raising the coolant level about 15-17 inches.
I have a similar funnel with a threaded PVC fitting epoxied on that fits the radiator... works like a charm. Do not fill it too high because it will rise until the t-stat opens and then do not let it run empty or you may introduce air back into the system.
 

Howski

Well-known member
Oct 19, 2009
1,483
209
Alabama
Ever get this sorted out? Having a similar issue after having successfully bled the system plenty of times in the past. What confuses me some is the water rushing noise has happened maybe 3 times in a week of driving since I worked on the cooling system. Coolant temps, coolant level (not losing any) and heat are all normal
 

The Fourth Amigo

Well-known member
Apr 20, 2009
641
2
I bought the vacuum kit. But while i was waiting for it to show up I tightened all of the hose clamps on the system and a day or two later the expansion tank level dropped. I topped it off and the sloshing noise is almost completely gone. I'm going to wait and see what happens before I drain the coolant to do a vacuum fill. Its been almost two weeks of stable operation.
 

Howski

Well-known member
Oct 19, 2009
1,483
209
Alabama
Sounds like we have a similar situation. Did the level drop running with the cap on or off? May flip the heater lines as mentioned above if I can’t sort it over the next few days
 

squirt

Well-known member
Nov 13, 2008
824
13
Los Angeles

I drive those streets in Echo Park (Los Angeles) pretty regularly to avoid traffic driving out of downtown. 1st timers are just the worst, as they get afraid toward the peak (blind intersection) and stop... which means that everyone behind them needs to start on a 30%+ grade, and FWD cars just spin the tires and inexperienced drivers just roll backward. I don't know why anyone would ever live on those streets.
 

The Fourth Amigo

Well-known member
Apr 20, 2009
641
2
DII is driving me crazy lately............

The sloshing sound has diminished and I'm not loosing coolant. Just changed the plugs and they all look fine, no overheating, brand new genuine LR expansion tank cap, engine running well.

Anyhow, the weird thing is that the coolant level in the expansion tank is lower when the engine is hot and returns to normal when cold. I believe this means that there's an air pocket still in the system. I'm going to have to try the vacuum kit.......

How much 50/50 coolant/distilled water mix do I need on hand for a standard drain and fill?