Thermostat change on Accord - amount of coolant?

Victor · 23rd December 2007, 09:36 PM

Hey everyone, I'm new here - great site!

I have a 1991 Honda Accord CB1 with the F18A engine. A few days ago it overheated. The upper hose would warm up fine but the bottom hose remained cold so it seems that the thermostat is stuck closed.

Tonight I drained the coolant using the radiator drain plug (I'm not sure if there's an engine drain plug) and removed the thermostat. I have the thermostat in boiling water right now on the stove - it's not opening. With regards to the coolant, only about 2.5 litres came out of the drain hole on the radiator, and another 0.5 litre came out of the bottom hose when I pulled it off. Is that normal? I was expecting 4 litres or so.

Also is there a particular technique to remove the old spring type hoseclamps? It was an absolute PITA to get off. I'm not sure how I'm going to put it back on. Might have to get screw type ones.

Cheers.

Horny_Devil · 23rd December 2007, 09:53 PM

there will still be coolent left in the block so expect another litre or so in there.

there should be a big 17mm bolt on the front of the block somewhere that you can undoo to drain the coolent from in the block.

the spring type hose clamps u grip in the jaws of a pair of pliers and just move it up the hose, can be a bitch at times, and also lube up the hose a lil

ur thermostat sounds like its fucked, if the water boils and it still hasnt opened, get a new one

Victor · 23rd December 2007, 10:33 PM

Cheers mate, I'll be buying an OEM thermostat from Honda tomorrow, here's a picture of the faulty thermostat, does it look stuck closed to you?

I should also mention that the fan never kicked in, I'm guessing this is normal when a thermostat is stuck closed since the thermoswitch won't be getting hot enough?

Will probably just leave whatever coolant that's left in the block as it's not too convenient for me to jack the car up.

DrRubber · 23rd December 2007, 10:37 PM

yea just replace it.......

if its got hot it may have fried your fan sensor but they seem to be relitivly durable so heres hoping

d16a7 · 24th December 2007, 08:02 AM

Quote:

Originally Posted by badcf4

yea just replace it.......

if its got hot it may have fried your fan sensor but they seem to be relitivly durable so heres hoping

just remember to plug it back in

ops:

and yes that looks like its seen better days

if honda isnt open you could always get a repco one.. ive had no issues with mine..

Victor · 25th December 2007, 12:45 PM

Thanks for the help guys. I bought an OEM thermostat from Honda, didn't want to take any chances. Only cost $33.75 after all so not worth risking aftermarket. Installed it and filled the car up with Prestone coolant, ~50/50 mix. The Prestone stuff looks to be yellow, but according to them it can be mixed with the green stuff

I've just installed the new thermostat and the car is not overheating anymore, however the fan still does not turn on when the car is warm. Both fans turn on when I turn the A/C on. Guessing it's a faulty thermoswitch? From memory though, the fans didn't turn on in the past either and the car never overheated even in standstill traffic. If that's the case, is it ok to leave the thermoswitch as is?

duncanb · 26th December 2007, 02:01 AM

Not 100% sure but I think that model had a drain on the front of the block.

Too late now, but the other way to get the old coolant out is to do a drain and refill with water a couple of times until the water looks pretty clear when you drain it. Then add about 2l of undiluted coolant and top up with water, which will give you close enough to a 50:50 mix.

And WHY have Honda stopped selling the Type 1 coolant?

23rd December 2007, 09:36 PM	#1 (permalink)
Victor Junior Member 700rpm (Idle) Join Date: Dec 2007 Posts: 5 Location: Auckland	Thermostat change on Accord - amount of coolant? Hey everyone, I'm new here - great site! I have a 1991 Honda Accord CB1 with the F18A engine. A few days ago it overheated. The upper hose would warm up fine but the bottom hose remained cold so it seems that the thermostat is stuck closed. Tonight I drained the coolant using the radiator drain plug (I'm not sure if there's an engine drain plug) and removed the thermostat. I have the thermostat in boiling water right now on the stove - it's not opening. With regards to the coolant, only about 2.5 litres came out of the drain hole on the radiator, and another 0.5 litre came out of the bottom hose when I pulled it off. Is that normal? I was expecting 4 litres or so. Also is there a particular technique to remove the old spring type hoseclamps? It was an absolute PITA to get off. I'm not sure how I'm going to put it back on. Might have to get screw type ones. Cheers.

23rd December 2007, 09:53 PM	#2 (permalink)
Horny_Devil Senior Member 18,000rpm+ Honda F1! Join Date: Jun 2002 Posts: 12,526 Location: Auckland	there will still be coolent left in the block so expect another litre or so in there. there should be a big 17mm bolt on the front of the block somewhere that you can undoo to drain the coolent from in the block. the spring type hose clamps u grip in the jaws of a pair of pliers and just move it up the hose, can be a bitch at times, and also lube up the hose a lil ur thermostat sounds like its fucked, if the water boils and it still hasnt opened, get a new one __________________ D Series Guru My Profile - My Website - My Build Thread V2.0

23rd December 2007, 10:37 PM	#4 (permalink)
DrRubber Senior Member 18,000rpm+ Honda F1! Join Date: Apr 2006 Posts: 10,693 Location: Auckland	yea just replace it....... if its got hot it may have fried your fan sensor but they seem to be relitivly durable so heres hoping __________________ Why do I need to comment on Robbie failing.......robbie is the grand master of fail

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23rd December 2007, 10:33 PM	#3 (permalink)
Victor Junior Member 700rpm (Idle) Join Date: Dec 2007 Posts: 5 Location: Auckland	Cheers mate, I'll be buying an OEM thermostat from Honda tomorrow, here's a picture of the faulty thermostat, does it look stuck closed to you? I should also mention that the fan never kicked in, I'm guessing this is normal when a thermostat is stuck closed since the thermoswitch won't be getting hot enough? Will probably just leave whatever coolant that's left in the block as it's not too convenient for me to jack the car up.

25th December 2007, 12:45 PM	#6 (permalink)
Victor Junior Member 700rpm (Idle) Join Date: Dec 2007 Posts: 5 Location: Auckland	Thanks for the help guys. I bought an OEM thermostat from Honda, didn't want to take any chances. Only cost $33.75 after all so not worth risking aftermarket. Installed it and filled the car up with Prestone coolant, ~50/50 mix. The Prestone stuff looks to be yellow, but according to them it can be mixed with the green stuff I've just installed the new thermostat and the car is not overheating anymore, however the fan still does not turn on when the car is warm. Both fans turn on when I turn the A/C on. Guessing it's a faulty thermoswitch? From memory though, the fans didn't turn on in the past either and the car never overheated even in standstill traffic. If that's the case, is it ok to leave the thermoswitch as is?

26th December 2007, 02:01 AM	#7 (permalink)
duncanb Senior Member 3,000rpm (Grandma Drag) Join Date: Jul 2007 Posts: 415 Location: Auckland	Not 100% sure but I think that model had a drain on the front of the block. Too late now, but the other way to get the old coolant out is to do a drain and refill with water a couple of times until the water looks pretty clear when you drain it. Then add about 2l of undiluted coolant and top up with water, which will give you close enough to a 50:50 mix. And WHY have Honda stopped selling the Type 1 coolant?