I bought a new coolant bleeder T - can I swap this out when the truck is cool without losing too much coolant or do I need to drain some?

thanks

 

I don't think , there is any coolant left, in the bypass hose, when the engine is cold, probably marginal, but what I do, when I change it or even expansion tank, I pinch hoses with set of specialty clamps, that I bought in Harbour Fright .There are four in the set with various sizes. Works a treat !
As for a bleeding, you should always run the engine to a operating temp.and look for air bubbles in the expansion tank, I usually bleed there with a expansion tank bleed screw loosened 1/4 turn.Then you could loosen the metal cup on the bleeder TEE, that you installed, but you have to be very careful ,not to loosen to much, otherwise fluid pressure will push out brass cap out and you will have a hard time to put that tiny hex cap back on the bleed T. Ask me how I know it .
The reason you have to loosen the T cap at the end and seep some fluid out , is simple.You have to let the air that sits at the top on the cap, just beneath rubber seal , out. When the engine is hot ,air packet there turn into steam and just sits there causing that little plastic T to disintegrate.This is the main reason they fail at the first place. Good luck.

 

the T bleeder is at the top of the cooling system so those hoses should be dry when you replace it. As a general rule you should bleed the cooling system again whenever you replace something.

 

Let truck sit overnight. Coolant should be drained from those hoses by the time you open that part up due to the way the system is designed. Don't run the system obviously until you reinstall the replacement (duh) and don't let anything get INTO the tubes while they're sitting open (double-duh).

IMO - I could be wrong so fair warning - you don't need to bleed the system if you just swap the T piece. I did it without closing off the tubes, nor did I bleed the system and she has run happily ever since, for about 10,000 miles now including going from east to west coast. I haven't had any bubbles in expansion tank nor do I have anything but a perfectly working cooling system, even out in this drought-blighted desert of ours.

 

Thank you, I'll try it like that on a cool morning this week.

 

am I missing something here? why would the hoses ever be dry, unless it is low on coolant. If the coolant "drained from the top hoses", there would have to be air in there.
If you are careful, you will loose only a small amount of coolant. And yes do it when it is cool, so the coolant won't burn your hands, not because it will have drained.

Edit: My Bad, I should have noticed this is LR3, not Disco.

 

Well honestly now you've got me wondering. When I swapped my bleeder valve (the T junction) I didn't lose any coolant, the hoses had a few drops in them as far as I can remember. I fit the new piece in and off I went, and it has been months of highway driving since. No problems, and zero temp fluctuations. My heater works great btw, no weird bubbles in expansion tank.

Temp sits just a hair under the halfway point on the gauge once truck is warmed up. Never goes higher than that.

Someone wanna chime in here? Should I bleed air out of my system? How?

 

I looked at pics of the t bleeder, and what would be its purpose if it was not to open up, fill reservoir until coolant comes out of the bleeder, then tighten it up.
By the way, I noticed Falconwerks, has a brass replacement bleeder for the LR3.
Either way, post how it goes.
On another note, if the LR3 temp gauge is anything like the Disco 2, it is worthless and only reads hot when it is too late.

 

Took me about 5 minutes to swap out. The new bleeder I put in has a push release valve. No coolant came out when I changed mine. Easy swap.

 

How did this hold up? Seems like a great solution.