[johnnybaroudjb]

So after my last track day i had some coolant spraying in my face. Would only leak when on track.
i know it may sound stupid but is this nut supposed to hold under pressure? When i pressurize my cooling system its the only leak i can find.

 

[silentservice703]

That tank is outside the pressure boundary for your coolant system.
How full do you keep that tank?
It should be just at "minimum" when cold.
That tank pressurizing would indicate that its drain line is plugged.....

 

[johnnybaroudjb]

I Keep at min when cold. Man i checked everything i cant find the leak. I've even replaced all the hoses with samco hoses and clamps. The only thing i havent replaced is the hose from the reservoir to the top of the rad.

 

[Panchomeneguzi]

So after my last track day i had some coolant spraying in my face. Would only leak when on track.
i know it may sound stupid but is this nut supposed to hold under pressure? When i pressurize my cooling system its the only leak i can find.

I Keep at min when cold. Man i checked everything i cant find the leak. I've even replaced all the hoses with samco hoses and clamps. The only thing i havent replaced is the hose from the reservoir to the top of the rad.

Is your drain hose line working ? Perhaps you could fill the expansion tank to full level and let it warm in a controlled place, just to check that the exceeding liquid is dripping from the hose. That hose is located next to the rear brake pump(at least in B3800). Perhaps it is pressed or closed somehow.
If you replaced the bolt and the washer from your picture, maybe the coolant is leaking from the upper black plug.

 

[johnnybaroudjb]

No coolant drain isnt plugged it works fine. I plugged it to pressurize it to see if anything was leaking on the bottle.
i ordered a new expansion tank and hoses anyway. Would rather be safe and replace the last remaining old rubber and clamps. Bike sat for a long time in the sun from previous owner. And now itsa dedicated track bike.

 

[silentservice703]

The pressure cap is the boundary. The expansion tank is just a vessel. Basically you are throwing away money.

 

[johnnybaroudjb]

The pressure cap is the boundary. The expansion tank is just a vessel. Basically you are throwing away money.

Yes and no, i tried to open that screw for the top off on that tank and it freespins the plastic is all stripped away in it. So i kind of needed one anyway. Found clean used tank for 30 bucks

 

[johnnybaroudjb]

So all that being said. I'm still at a loss where the coolant is coming from lol. I've pressurized the system and sprayed leak detector soap all over it and nothing. I may drain the coolant next and try it with strictly just air in the system to see if i can locate a leak.

 

[jaramharamharam]

So all that being said. I'm still at a loss where the coolant is coming from lol. I've pressurized the system and sprayed leak detector soap all over it and nothing. I may drain the coolant next and try it with strictly just air in the system to see if i can locate a leak.

How did you pressurize the system? I had the smallest of hairline cracks on my F3's rad. Was only able to find it when I took the rad to an industrial rad service shop that works on big truck systems. The were able to spot the tiny tiny crack and fix it. Also, you prob checked this but is the washer on the nut you pictured above in good shape? When I changed mine, the nut was rusted to hell and the washer was almost completely destroyed. Ordered one from Startwin. Good luck with the repair.

 

[johnnybaroudjb]

How did you pressurize the system? I had the smallest of hairline cracks on my F3's rad. Was only able to find it when I took the rad to an industrial rad service shop that works on big truck systems. The were able to spot the tiny tiny crack and fix it. Also, you prob checked this but is the washer on the nut you pictured above in good shape? When I changed mine, the nut was rusted to hell and the washer was almost completely destroyed. Ordered one from Startwin. Good luck with the repair.

I tapped into a hose fitting with a T and clamp and a hand pump, pressurized to 1.0 bar.
No the nut doesn't seal. The threads are destroyed on it.