Coolant bubble / burping question (1 Viewer)

[MrLinsky]

Hello,

Two questions:

1. If I have a 'T' installed to flush the cooling system, at the firewall, between the heater core and top drivers side of the engine, could this cause a high spot that would trap air and make it difficult to burp and stay burped? It is the highest spot in the system and comes up pretty close to the hood.
2. Should the cooling system suck fluid back into the system from the overflow? I assume this is how it works as this is now most other cars that you fill the cooling system at the overflow tank have worked in my experience.

BACKSTORY

I have a 1982 FJ60. I've had intermittent cooling issues over the last 5 years or so and the cruiser has spent more time parked than on the road. Long story short, on the way to catch a flight, blew a heater hose, cut up the rear aux heater hose to make it work on the side of the road 20 min out from the airport. Got back, picked up heater hose and plumbed it wrong. Drove the 60 miles home with it overheating all the way.

Parked the cruiser then and it sat for 3 years with a few half a$$ed afternoon attempts to revive it. About a year ago, I made a proper effort, had the radiator rodded out, new heater core, new water pump, new tstat, gaskets, temp sending unit, heater hoses and clamps. put it all back together and the gauge was still pegged. So I put a flush kit in it and installed a T at the back top by the firewall. used some chemicals from the parts store, a bottle of prestone something or another and it still showed it was overheating. After all of that, turned out the sending unit I got was bad or wrong or the factory gauge is bad and after installing a manual gauge everything showed the right temps. It probably wasn't overheating much at all after I got the hoses rerouted correctly.

But now I cannot get the effing air bubbles to stay out of the beast. I can get it burped OK I think. But after a few trips to town and back, the whooshing noise comes back under the dash. Reburp and it goes away for a while again. So I'm getting air in there somewhere I reckon. I am wondering if the T I installed to flush the system is creating a high spot in the system that allows air (and possibly sucks air in) to get trapped in a spot it won't just purge out of on it's own? I've got a new tstat on order from toyota and the gaskets from them to install it and I was going to just take the T out as I don't really need to flush it again right away anyhow. I've ordered a new radiator cap from them as well as the one I have seems to let fluid out of the radiator into the overflow tank, but it never sucks any back into the cooling system (which may be because of air trapped in the system absorbing the pressure I guess).

Thanks for reading and for all of the help and advice I've gleaned from everyone here as a lurker for many years.

 

[klinetime574]

I recently used one of those coolant flush tees. I left it installed and I'm pretty sure it's leaking. It's coming off whenever I feel like dealing with it. No harm though cause the 60 just sits in the garage

 

[micruz60]

1. Yes, check the cap on the tee, does it have a sealing gasket? Like klinetime said, air can get in there. But I think you are on the right track getting a new radiator cap.
2. Yes, radiator cap is involved here, 9-13 psi cap rating (i believe).
Good luck!

 

[sbelinge]

I can't speak to the flush valve, when I've done mine I just use FSM procedure. I don't know if it's any easier that way but it gets the job done.

However regarding the overflow tank you are correct. The radiator will both burp and refill itself from the overflow. You do need to fill the radiator from the cap first. I've never gone trough the burping process others have written about. I could be wrong but a properly set up system should burp/refill itself just by running through a (or a few) normal heat up & cool down cycle of the engine via the overflow tank. Maybe I've just been lucky.

 

[MrLinsky]

"I could be wrong but a properly set up system should burp/refill itself just by running through a (or a few) normal heat up & cool down cycle of the engine via the overflow tank."

<<< I've always had this experience as well. I've got a new piece of heater hose to replace the one I cut for the T fitting once the engine cools down, I'm hoping it goes back to the .: Just Working :. stage here again soon.

 

[White Stripe]

Since you've gone to so much work already, buy a coolant funnel. They work very well. Not much money. With the funnel on the radiator, let the truck idle for a while with your heater valve open.
http://www.tooldiscounter.com/ItemD...vVPxH1W2E_3KluOyiDGeqjUUF71J0_qnjcaAvW38P8HAQ

 

[guerasfj60]

Yes to the oem cap. At first the tee helped me burp the system but eventually got rid of it because it leaked. I followed the burp advise found here; funnel, incline, massage rad hose, open rear heater. I topped off the overflow a couple of times. Frustrating at first.

 

[MrLinsky]

Well, I'm not sure if the T was sucking in air or not, but I took the radiator cap off and upon inspection it was all crudded up with gunk from the cooling system, probably residual gunk from my initial flushing. I picked up one from the Autozone and figured it wasn't going to be worse than what was on there (knock on wood....) until I get the OEM one this week. I did replace the T with just a section of heater hose and the new radiator cap is now also sucking fluid in from the overflow reservoir so I think it may be on the way to being resolved!

If the existing aftermarket cap is working, do you think it would be better to just keep the new OEM one as a replacement for when it goes bad? Or would it be alright to just replace with the OEM right away and wash the aftermarket one I just got and set it on the shelf for a just in case spare? I didn't think the coolant would corrode anything on there (especially after a good wash). Anyhow, thanks for everyone's suggestions, I did also order a coolant funnel as I imagine I'll be doing it all over again when I replace the tstat next time around.

 

[Beehanger]

ast 5 years

I recently used one of those coolant flush tees. I left it installed and I'm pretty sure it's leaking. It's coming off whenever I feel like dealing with it. No harm though cause the 60 just sits in the garage

what are the coolant flush tees everyone's referring to? and @micruz60 if the t lets in air doesnt that mean that the coolant system sint fully pressurized and could lead to overheating?

Thanks,
Dan

 

[micruz60]

what are the coolant flush tees everyone's referring to? and @micruz60 if the t lets in air doesnt that mean that the coolant system sint fully pressurized and could lead to overheating?

Thanks,
Dan

The tee is at the highest point of the cooling system, so if it is topped off and sealed* the proper function of the radiator cap and overflow bottle should purge any air.