Would I need to drain coolant to cut into the top radiator hose?

[Slappy]

I'm doing my EGT, Oil Pressure, Boost and Water Temp gauges this weekend and I think I've got a good gauge on most of it. I presume I don't need to drain the oil if I let the car sit overnight before touching the oil switch, boost is easy, EGT bung is getting welded in tonight but I'm not sure about the water temp.

I've got SAAS gauges and bought a hose join recommended for the gauge, I just don't know if I should be draining the coolant before doing it? I THINK it should be find as long as its all depressurized and the cut is with a very clean knife to ensure no loose bits?

I'm thinking I'll take some pictures and do a little guide - I've had a lot of trouble working through this little project as a first timer!

 

[Adhaul]

Wow sounds like a bit of an over kill to me, but each to their own, as they say knowledge is power!
Okay it's really very simple, take off the radiator cap, cut your hose & yes you are going to lose some coolant, put in the fitting, clamp it up, top up the radiator first with clean (not chloride treated) water, or if your really fussy, flush the whole lot out and replace it with new coolant. The minor dilution factor will not really affect anything. Oh don't forget to bleed the system I think there are 2 plastic screws on the heater hoses near the firewall LHS engine compartment. Don't believe the stuff the Nissan dealers will tell you either, had one of them tell me they must bleed the system because they needed to reset the computor as part of the job wanted $180 to do the bleed.

 

[Slappy]

I shouldn't lose much coolant though right? It would just be whatever is left sitting in the hose ones the engine cools back down?

Sounds easy enough, just wanted to be cautious lol

 

[Horatius]

No, just cut the hose (you will lose a small amount of coolant), fit the adaptor and see how it goes. Sometimes you might need to cut an inch or so out of the hose to remove possibility of the bend kinking depending on width of adaptor.

Then top up with demineralised water (about a dollar for two litres at the supermarket). You should only lose half a litre or so. Or if you're really fussy a 40-50% glycol to water mix (assuming it has the green glycol stuff in it).

 

[Horatius]

^ps. only do it when the engine has cooled down. Shouldn't be any air bubbles to worry about (but check it after a run anyway). You'll lose what was in the top tank and most of what was in the hose, not that much really.

 

[Cowboy550]

Hay Slappy how did you go with the gauges ?

 

[Slappy]

Hay Slappy how did you go with the gauges ?

So the welding shop didn't get around to welding my EGR bung in and we've had shocking weather over the weekend so I didn't get everything done, but I did get my boost and water temp sensors in and tested with the gauges on a test circuit and its working sweet. I couldn't take many pics since the weather was really bad but I might do a quick video once it's all in just to show exactly where I hooked everything in.

Boost went in right before the stock boost sensor on the top of the motor and the water temp is right in the straight part of the top radiator hose, lost maybe a litre or two of coolant but as suggested above just topped up with distilled water and ran up to temp air it out. I actually jacked the front of the car up to make sure all the air was coming up.