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TR2/3/3A Burping a TR3

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JFS

JFS

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Just put the radiator back into the TR3, added antifreeze, left the rad cap off, started it and waited to add more antifreeze. The coolant is not circulating and the temp goes up. Replace cap, restart and again, no circulation and temp goes up. Didn't have a problem with either the water pump or the thermostat when running a couple weeks ago. Have had radiator in and out numerous times before but never had this problem. How do I burp the air?
 
High high is the temp going when you say it goes up? Once the thermostat opens it should burp itself. If it goes above 200 degrees (actual ,not gage reading), it will flow or you have a problem other than "burping".
 
How do you know that coolant is not circulating (top hose stays cold?).

FWIW - I always drill a small hole (maybe 1/8") in the thermostat (some come with one) to let some air and coolant move through even when it is closed.
 
John, well over 200 gauge reading.

Geo, Top hose is hot, bottom hose cold. Thermostat has the small hole.
 
I did nothing with the thermostat; it's been running as it is for many years.

Years ago i plugged the bypass pipe as described by Bob Schaller in his yellow booklet. I'm wondering if this is preventing it from burping.
 
Could be -- I also blocked mine but put a 3/16" hole in it.

bypasshose_zpsc06926c1.jpg
 
I juist reread Schaller's booklet and see that he doesn't mention drilling a hole in the plug, but I have heard of others doing that as well. I'll drill the hole tomorrow. Hope I don't have to pull the thermostat; that would set me back at least another week waiting for a gasket.
 
FWIW if it comes to that - I always just make my own gaskets for the thermostat & bottom of housing - I can make ones that exactly fit the castings and look much better than store-bought. I usually use that dark grey gasket paper - cuts easily if you get it wet first or use the ball peen hammer method to tap out the outline.
 
Even heavy cardboard will work for the thermostat gasket, in a pinch. I'm trying something different this time, ran out of gasket material, so I cut one out of the yellow Prestone jug. Seems to be working fine so far.

I really doubt the problem is an air pocket, or lack of a hole in the bypass. But the bypass is there for a reason, I don't think it is a good idea to block it off entirely, so you might as well go ahead and add the hole.
 
No need to pull the thermostat, that bypass hose will come off easily. In fact last weekend a friend of mine had it come off while he was driving to our morning breakfast. The sweet smell of coolant in the morning, ah!
 
Only replaced the wobbly 20 year old electric fan.
If not an air bubble, I'm thinking water pump. I'll check it this morning.
 
JFS said:
Only replaced the wobbly 20 year old electric fan...
Click to expand...

Oops, when you said in your first post "Just put the radiator back into the TR3..." I assumed (shouldn't do that) that the radiator had been out for some service and was 'known good'.

What you describe ("...well over 200 gauge reading....Top hose is hot, bottom hose cold") sounds very much like a blocked radiator.
 
Duh. Am I embarrassed. I plead an extended senior moment (I'm 73.) I didn't finish tightening the alternator bolts. The fan belt was loose. Tightened it up, the water pump now works, and the non-problem is solved.
The new fan kicks in at 185 and out at about 170. Too low? I'm using my old temp sensor and control box and can't find any means of adjustment.
 
I do that all the time! I was thinking water pump, but couldn't think of a way it could completely quit pumping. Belt will do it, though ...
 
JFS said:
...The new fan kicks in at 185 and out at about 170. Too low?
Click to expand...

Is that gauge temperature or sensor temperature?

If the latter, where is the sensor mounted?

I do not use an electric fan, but those temperatures seem about right for a sensor on the lower hose (which has always seemed to me to be where one should go) -- might be too low if using the upper hose.

If you are describing gauge temperature then it sounds too low but you'll probably want to verify what the gauge is telling you with an IR thermometer.
 
That's gauge temp. The sensor is a fin mounted probe placed in the center just above the fan. I could move it below the fan if I could find a new probe mount.
 
I agree with Geo: That's pretty low if your gauge is accurate. The thermostat won't be fully open, meaning the fan will run more than it has to. But, it won't really hurt anything either. You've got an alternator, so no worries about running the battery down.

There is a DeRale kit with a fin-mounted probe (just pushes in place, so easy to move) and a relay with a temperature adjustment.
https://www.amazon.com/Derale-16749...8&qid=1410023835&sr=8-2&keywords=derale+16759
 
Thanks Randall, but I found the tiny nylon adjusting screw hidden by some wires entering/exiting the fan control box.
 
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