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'93 U225 radiator overflow bottle.

January 01, 2024, 04:20:22 pm

Silly question #345.....
Is the overflow bottle on my radiator like a cars?
In that the coolant level rises when hot then siphons out to provide needed coolant to the radiator when it cools?

OR is it a level indicator for coolant in the radiator?  Kind of like a sight glass?

 I ask because I see a hose coming out of the bottom of the jug, thinking that after I add to the jug it may pass coolant to the engine/radiator  by gravity.
 After a couple of cycles of bringing the engine up to temp (by taking a trip down the road) and letting it cool, the level in bottle remains about 1/2 full.

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Re: '93 U225 radiator overflow bottle.

Reply #1 – January 01, 2024, 04:28:32 pm

Yes, your overflow reservoir should change level with coolant temperature.

Higher when warm. Lower when cold.  And, with the proper radiator cap, the engine will "suck coolant" from the reservoir, but ONLY if the cooling system itself is totally full. 

IMPORTANT: If the fluid level in the reservoir does not change from cold to hot, you have AIR in the cooling system.  You need to totally fill the system (remove radiator cap and top off).

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Re: '93 U225 radiator overflow bottle.

Reply #2 – January 01, 2024, 04:29:28 pm

Yep

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Re: '93 U225 radiator overflow bottle.

Reply #3 – January 01, 2024, 05:41:51 pm

I will say that taking the cap off in the right direction helps.
A LOT.
Radiator = 1 gallon to top off.
Overflow = 1/2 gallon.

  Done.
  Thanks for the air bound tip!

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