I am going to replace my top rad hose later. Can I just remove the old one then fit the new one and top up? My coolant was replaced a year ago when my cam belt was done. I don't want any airlocks forming, but I don't want to drain it if I don't have to.

Any advice much appreciated, Martin.

 

I'd first remove the pressure cap on the header tank before taking the top hose off. Then fit new one. Then reinstate lost coolant, Then with cap still off, let car idle and get upto normal operating temp, and then wait for fans to kick in at 91C. This, hopefully, should be enough to burp the system.

Then replace cap, and go for a test drive using plenty of boost. If you do have an airlock: temp going beyond halfway and/or heater cold when on "hot" and/or a cold bottom hose, then you'll have no choice but to drain and catch the coolant and reinstate it by the "correct method" -- do a search and all will become clear on said method...

 

Thanks joz, I am ok with the the draining and refilling method. I guess I'm just being lazy as it's so easy to get to. I'll do as you said and fingers crossed it will be a 30 min job.

Martin

 

Yeah, I agree. So easy to not wanting to do the full draining thing...

 

No need to fully drain- just remove enough to get the top hose as empty as possible.
Get a turkey baster (my wife doesn't know where hers went ) and empty from the header tank while squeezing the top hose. Keep this coolant for reuse.
When you can't squeeze any more then the top hose is pretty empty so swap it.

If you've got a newage car then refill at the radiator cap first. When the rad is full then start filling the header tank and squeezing the top hose to get rid of air.

 

Ok, all done. Just as awkward as I thought, but not difficult. Now the heater blows red hot. The top and bottom hoses are hot but the fans won't kick in. The temp gauge is about 1 mm higher than normal. I've just put a/c on and the fans work fine. Is it just a case of more running with the cap off or the dreaded drain!

Any ideas?

 

Just to go sideways, why did you change the top hose?

 

Alcazar, I changed it because it had small spilt in it. I had a ps pump leak and some of the fluid splashed on the old hose. I cleaned the hose off, but I missed a patch of gunk and over the last year I suppose it's rotted the rubber. The spit and area covered by the gunk had gone very soft.

 

Ah, OK, it's just that I'm toying with the idea of fitting a temperature sender into my top hose.

Seems like a bit of a bugger to get off at the engine end though?

 

I was surprised how easy it was. It is tight but possible. I had to remove the air box and trunking. This gives you better/only access to the screw/bolt clip. I removed the rad end first then just pulled the hose while wobbling it around. Refitting was easier than I thought, I put the end of the hose in boiling water to soften it and it just pushed on. I did use a socket and an extension to get to the bolts, much easier than screwdrivers!