gailT25

I would if I could find it. Girlie non-mechanic changing the radiator on Civic 1.3 1995. All is going well, new rad in, but can't locate the drain bolt on the engine block. oI need to, or will the engine drain simplay cos the hose was taken off anyway? Many thanks, any help gratefullyreceived.

The93egg

im pretty sure its a big *** bolt right in front of the radiator, on the block

94EG8

Behind the exhaust manifold there will be a drain/frost plug or a block heater if one has been installed.

gailT25

Thanks for your help, guys. Neighbour who is mechanic came back and pointed out the obvious - after I'd just given up trying to find it, and had refilled with coolant as it was getting really dark and I had to have her back on the road. All is running well - or I will find out tomorrow if not.

honda.lioness

Did you do an air purge of the cooling system?

Without removing the drain bolt, some coolant will stay in the block. But lots do coolant changes without removing the drain bolt. It is not as thorough; a couple of cups of the old coolant out of about a gallon stays in there. But it is better than no change at all.

gailT25

Seems fine today, done about 50 miles. But good to know only a little of the old coolant remains. If by an air purge you mean just the bleeder screw on the top, yes I did. If you mean something more, no I didn't.

Only joined forum yesterday. Wish I had sooner. Just discovered the FAQ section. Mmm, hindsight is good.

honda.lioness

An air purge is necessary anytime the coolant system has been opened--a radiator replacement; coolant change; thermostat change; etc. The procedure is in the owner's manual, or you can find it at the free online repair guide specific to your Honda at autozone.com. It involved running the car with the rad cap off or very loose, heater setting on high, until the fan comes on twice. Getting the car to warm up so the fan comes on twice takes 20-45 mins, depending on the ambient temperature. Air in the system can cause sensors to send the wrong signal to the computer, messing up ordinary performance. The air might burp out on its own (via the reservoir, whose cap is vented to atmosphere), but its best to heat it up etc. per the procedure in the owner's manual or similar.