So I have a tiny leak (likely a split) somewhere in my coolant lines that is allowing small amounts of coolant to spray onto the engine.

I am working my way through the lines to see if I can find said leak and I was wondering what the "joints/connectors" are for in the line going from the AST to the overflow tank (N3A1-15-380C)?

Can I just replace this with one single line or are the connectors serving some purpose?

I thought they may be one way valves but either that is not the case or mine are faulty........

Thanks Tom.

 

Over at 3-1 Shinchi, Fuchu, Aki, Hiroshima Prefecture that is known as a チューブコネクタ. Nothing special, no check valve in there.

You mention a tiny leak and spraying on the engine. While there are dozens of places it could be coming from, if you find that it is almost an invisible vapor getting all over the top of the engine my favorite place to look first is the spring clamp holding the hose that goes into the throttle body (circled in red here). Of course that's assuming you haven't deleted that connection.


That 25 year old hose is hard and the clamp is weak. If you are very very lucky, that hose has been disconnected at least 12 times to burp the cooling system of air after a coolant change so the rubber has not "fused" to the nipple like most of the coolant hoses. Under pressure and engine heat the old spring clamp weakens just enough to allow a bit of vapor out. Since the hose is at the top of the engine the vapor drifts everywhere and anything aluminum gets a fine white powder on it. Once the car cools down there is no leakage. After a hard drive the engine compartment smells of antifreeze, but there is no sign of a leak except for a tiny bit of crust on the bottom of that hose. If you haven't done so already, it's time to check all the small hoses and replace all the spring clamps. In fact if you intend to keep the car for many years I would suggest you give Ray a call, he can make a "coolant hose kit" order for you.

 

It my understanding that the connector in the hose is actually a restrictor which acts to regulate flow.

 

Maybe, while I've never taken the the thing apart, I have blown through it on both ends and there doesn't seem to be any significant restriction, but anything is possible.

 

Not knowing exactly where you're leak is, have you checked your turbo coolant hoses?

 

That is just a quick connect for assembly. The overflow tank comes from the factory with a short length of hose with that plastic hose joiner at the end. When they built the cars, they would stuff the engine in from the bottom then connect the hose from the AST to that hose joiner.

As far as I know there isn't a restrictor or anything in it.

You can use silicone vacuum hose for that hose, I've been running some 6mm hose from Boost Controller.com for YEARS. BTW, this is a very low pressure system so the SVH is fine, you don't want to use it anywhere else that would see pressurized coolant.

In other words, it just needs to be a solid hose from A to B. It can't have any pinhole leaks or coolant pushed into the tank can't be sucked back in and it will cause the overflow to spill out the top.

Dale

 

Hey Guys,

Thanks for all the information and advice, as always it is greatly appreciated

Apologies for the old/crude picture (I will take some better ones when I get chance), but if my memory serves me correctly; the areas I found dried "fluid" (i am assuming coolant) are shown in red. It's all coming from the front somewhere and either spraying or being blown towards the engine block by the wind when driving. The spray could be found on the rad outlet tank, the front of the turbos, the Y-pipe, and the front cover of the engine. The furthest forward I found was sitting on the crossmember that is supporting my intercooler. Hence me thinking it might be the AST-Overflow tank line as it runs along there.

Any thoughts on possible sources for the "fluid"would be appreciated!

Thanks, Tom

 

As they say a picture is worth a thousand words! I'm with Sgtblue, check your turbo coolant hose. If you haven't ever changed it, put in a new one cause they get roasted connected to the turbo.

 

Yep I will be sure to check, I was assuming that all my hoses should be brand new as my full engine bay overhaul was less than 300km ago!

 

Uhmmm lets see...
300km divide by three, carry the one, add 2.5, check the wind condition, Oh I got it! That's 186 miles ago!
If they are all new hoses then I bet there is a hose clamp somewhere that needs just a 1/4 turn more.

 

Another possibility is the radiator cap pedestal on top of the thermostat housing. There's an O-ring between it and the aluminum t-stat housing. That or the fill cap could be a leak point.

Dale

 

Thanks again for the suggestions guys.

I will move the V Mount this weekend to that I can have proper clean and check all these areas. Hopefully its a simple fix like a loose clamp