I took the car out for a drive last night and the hose from the top of the rad to the thermostat tower came off spewing out the antifreeze. I had the car towed home and today replaced the hose and clamp and refilled the rad through the coolant tank. I ran the engine for a few minutes and squeezed the hoses but there doesn't seem to be much fluid in the top hose although when I squeeze the top hose I see movement in the coolant tank. Is there any other way to get airlocks out of the system?

 

Do you still have plastic thermostat housing or upgraded aluminum one? Is the water pump original or been replaced? What year car? How many miles? Have you ever changed the coolant? What color is the coolant? These questions could help answer you but we need more info.

I myself have a 97 and recently had the upper and lower hoses off to do my timing system. I opted to replace the thermostat housing to aluminum and put a new water pump on with a metal impeller. The water pump I took off had a white plastic impeller, which I believe changed to a black plastic impeller later on but both have been known to be an issue if certain coolants were used. My overflow tank specified Jaguar “yellow” coolant and the stuff I drained out was orange, most likely dex-cool. Dex cool was made for gm cars with aluminum block like our jags but also had chemicals in it that would literally eat the plastic impeller. If your hose blew off it could have been several factors such as;
-wrong coolant
-worn hose clamp
-stuck closed thermostat causing over pressure
-or another factor someone smarter than me may know the answer to

when i reassembled everything, I took the cap offf the thermostat housing and filled to the top. Then I ran the car and topped it off while squeezing hoses to “burp” out any air. I waited for the thermostat to open and again filled to the top, squeezing hoses. Then I topped off the overflow to spec, ran for a bit and a good ride. Let it cool down overnight and checked in the morning and re topped off where needed. Maybe not completely orthodox by the book but it worked for me.

 

Hi Steve thanks for your reply, Here's more info. It's a '97 coupe with around 9,500 km on the rebuilt engine I had installed in the winter of 2021. Everything outside the motor was replaced with new including all hoses, water pump, thermostat. ac compressor etc including a new plastic thermostat tower and the car gets the oil and anti freeze changed before it gets parked for the winter. I'm 99.3% sure it was the worm drive clamp that came loose but I'll replace the thermostat just to be sure and try running the car longer and burping the hoses again tomorrow.

 

Fill the over flow coolant tank (the one in the rear of the right front fender) 1/2 full which will allow the system to fill and find it's own level. If it's like my 2005 XK8 you can see the tanks fluid level by opening right door all the way and looking between the A-pilar and fender using a flashlight.
I fill mine with a large syringe through hose at filler cap. Remove the dorman cobra clamp then hose and insert syringe and push in coolant and replace hose.

Jack

 

If you have an air compressor, I bought a few years back and it is FABULOUS!!

It's the UView 550000 Airlift Cooling System Leak Checker and Airlock Purge Tool Kit

Does the job quickly to create a vacuum in the system and then you flip the valve and it sucks the coolant into all of the crevices.

 

never ever have i ever had to vac fill these

these are the easiest cars ever to bleed

 

I agree. I have done a full coolant change on my car three times since I have owned it, with multiple plain water flushing changes each time. I have never had the slightest problem and just run the engine and top-up until no more can be poured in.

Richard

 

+1

The coolant tank in the engine bay is the highest point for coolant in the system. It is essentially a self bleeder barring any damages. You can squeeze the radiator hose to help it along but after multiple flushes on two different XK8s I have never had any issues.