First of all let me apologize if this has already been done.

Every place I have looked on this forum says to drain the coolant by pulling the bottom radiator hose. Being lazy, I thought I would try a different way.

I change oil buy using a vacuum tank. So, I removed the banjo bolt, pushed the suction hose of the vacuum tank down the hole to the bottom of the radiator and sucked out a little over 3 gallons of coolant in 5 minutes. Then I drained the aux tank in the same way.

When I did remove the lower hose, I got nothing, which means I drained more than I would by pulling the hose. The lower hose is attached above the bottom of the radiator, and would normally leave a little in radiator. The vacuum tank sucked it dry.

Cheers....Jimmy

 

JayCee, Did you turn over the motor to pump the coolant that is in the engine water jacket to the radiator? You have effectively drained the radiator but there is more old stuff in there.

 

Hi Jimmy

Wondering why you decided to drain the Radiator, as if you wanted to change the water, it sort of defeats the object of missing the opportunity of being able to flush away any build up of crud that may have been laying in the bottom of the Rad.

As well as the Engine, as Brad has said.

 

Why turn over an empty engine? A water pump needs water to pump. It can't pump air to get water out (plus you risk killen it whilst doing so)

 

As the vacuum sucked the coolant from the radiator, coolant from the engine flowed into the bottom of the radiator through the lower hose. The system contains about 5 gallons of coolant, I was able to remove 4 gallons this way. The rest is probably in the heater and over flow.

If you drain by using the lower hose method you will get the same amount, except you will leave a couple of inches in the bottom of the radiator. So I was able to get a little more using this method. Having done it both ways, I got more out and I didn't have coolant all over the garage floor.

I then refilled with distilled water, let her run for a while. (did a flush) Then add the 50/50 antifreeze mix.

...Jimmy

By the way vacuum tanks are cheap...got mine for about $30 on Amazon. It also makes oil changes easier.

 

I may try this in May when I do my coolant. I had back/spinal surgery in September 2016 so not having to get under the XJS will help.