Greetings everyone,

Thanks to Grant's sticky and Greg's advice, I am in the process of renovating cooling system and bleeding air from the it on my newly acquired XJS 5.3L. I parked the car on a hill and followed Greg's advice. Removed cross pipe cap and header cap. Filled system from cross pipe cap. When header tank started to overfill, I put cap back on header tank. Filled cross pipe cap until full. Started car with defrost on. Undid brass plug on LHS radiator while running . . . see results . . . lots and lots of air bubbles.

Is this normal? Something I should be concerned about?

Size restrictions made me cut the video down to very short clips but bubbles were coming out for a good 25 seconds.

Topped up water through this hole until no more air came out. Plugged hole and drove for half hour.

Will repeat tomorrow unless advised otherwise.

Thanks Grant and Greg!!

 

Charles.

Well done and nothing drastic for sure.

I go one step further, and remove that radiator bleed plug WHILE i am filling the system.
When the coolant flows from the header tank, cap it, continue filling, and when the coolant, minus the bubbles, flows from the bleed hole, refit the pug, top off the filler spout, fit the cap.

ALSO, make 110% sure the heater tap is in the ON position. Looking at it, the arm is pointing DOWN. I unplug that little hose, and the vac loss defaults that tap to ON, if its not rusted closed. Air in the heater matrix can be a mongrel to bleed out.

I DO NOT run the engine at all, just SLOWLY top up, allowing the air to find its way out. Starting the engine after, and let it idle while I check for leaks etc, and then shut it down, go away, let it cool. Remove the filler spout cap, and top up if needed.

The slower you fill these beasts, the less issues you have.

Not sue if you have this one so here it is.

 

Since I have a water pump replacement ahead of me I'm gonna try the 'non running' method, Grant. The 'running' method gets very messy !

Cheers
DD

 

Doug,

Drain that steel header tank before filling, it just allows air and coolant to get into that tank from the crosspipe much easier than if still half full of old stuff.

I do 1tr at a time, and SLOWLY, the amount of gurgling, especially after a water pump replace is scary.

 

Devils advocate here but that sure does look like water and only water - if it is then that is a truly bad move -

 

Dear Grant,

Thank you. Glad I am on the right track.

Indeed, the water pump has been replaced!! I went the whole hog, also replacing the heater valve (that the previous owner had removed and not replaced). Will work on air bubbles again tomorrow (this time removing the plug as suggested when filling) and see how it goes. Will proceed SLOWLY!!

Thanks a million!!
Charles

 

When I replaced my heater valve, all hoses, waterpump & rad not too long ago, I just did as suggested above - very slow filling from the centre pipe cap, with the rad bleed point open (I also added a bleed point on the heater hose at the rear). Closed bleed points once coolant came out. The centre pipe coolant level sits a couple of cm from the top, & the header tank is 100% full & coolant sits in the pipe to the atmospheric vent tank.
I've warmed the car through a couple of times now & there has been no change.