2015 Corolla GLi coolant leaking from T valve

[engnr.mubashir]

So there was no T valve when I bought this gli 2015 model but T valve was found inside trunk hiding behind the spare tyre don’t know if it’s genuine or not but check on the Internet looks genuine to me as pink coolant traces were there so looks from this car as heater core was filled with pink color coolant when I reconnected it before.

So today I decided to install it again bought new T valve seal and fixed it and I started pouring water to check for leaks found out flange from bottom was leaking if car is not running and as soon as I start the car it stops leaking.

Also I found traces of salt on T valve area looks like previous owner put hard water in the car that looks like eaten up T valve sealing area as shown in pictures below.

Anyone can help what is solution or can this T valve seating area be replaced or not or is it welded to cylinder head.

One more thing to mention bypassing T valve stops leaking.

[hash4u]

cleaned the area with sand paper and using the right silicone sealant?

also T valve removed indicates bigger problems
car must have overheated in the past

[engnr.mubashir]

What type of silicone is right silicone Grey or Black RTV.
Should I apply before and after placing T valve ?

[Xulfiqar]

No silicone will seal the rubber to the metal. You need to use a blade and a brass wire brush to clean the surfaces, check for pocket holes.

If you see pocket hole marks on the sealing area, the gasket wont seal, you can remake it with aluminium infused epoxy and sand it flat again, (people who use plain water or brackish water instead of coolant assume “kuch nai onda” and then sell the car as jenwin/jenyan etc etc, qaseeda, nazm etc etc.

You can try sealing with a paper gasket on the outer flange perimeter but it usually fails after a year or so.

[engnr.mubashir]

I have dremel tool will be looking for brass brush attachment will give it shot.

Is this aluminium infused epoxy easily available.
Where to find this easily in karachi.

[askai37]

try liquid gaskit instead of silicon. but after applying liquid gaskit fix tvalve flange with in 5 minutes

[engnr.mubashir]

thanks and I have found permatex brand while looking gasket maker online.

[engnr.mubashir]

They may have just bypassed it normally because most of the mechanics think T valve is necessary in winters only it has nothing to do with summers. Also heater was also bypassed I have re connected it too.

Any Idea to check whether the have gone through major heating event.

[helper_learner]

Also heater was also bypassed I have re connected it too.

Now, keep an eye on heater core leakage.

[engnr.mubashir]

Not leaking I have thoroughly check inside under the dashboard on floor liner.

[engnr.mubashir]

Thanks everyone for the help I have managed to fix it without applying any silicone or gasket maker to valve seating area.
Just cleaned the Valve seating area with brass wire brush attachment using Dremel tool.

But one trick I got from Mechanical field expert was to align the T valve on flange first with the help of silicone as he said aligning is most important otherwise you will be wasting your time.
So I aligned it and it went all ok without any issues.

Now dripping is stopped completely have run car almost for a day no heating no anything.

[askai37]

alignment marks are given on body side just align bypass pin on tstat within those marks

[engnr.mubashir]

Flange gas no alignment marks and I was talking about that.

[Xulfiqar]

There is no alignment for this flange, you install the thermostat with its rubber gasket and its jiggle valve at top 12 o clock position. Install cover over studs and tighten down evenly.

[engnr.mubashir]

Yes there is no flange alignment but required in my case don’t know why even though I tighten down bolts gently still ended up having leaking flange.

I don’t remember whether I place thermostat 12 o clock position according to jiggle valve . Is this thing concerning?

[engnr.mubashir]

One more thing to share here average increased by almost 1.5km/L on Highway after installation of T valve don’t know why I delayed this thing even I was aware to this.

[Xulfiqar]

That jiggle valve alignment is critical as it helps system burp trapped air as you fill the system,

Air rises above liquid, thats why its kept at 12 o clock position. And the flange tightening is done evenly with a 1/4 inch ratchet set,

Its a good idea to apply some coolant on the seal too so it can slip against the flange as its pulled in and gets squished tight. It is also mandatory to replace the seal with a new part if its old, perished or hardened.

[engnr.mubashir]

Thanks. I have placed T valve according jiggle valve at 12 O clock position.

I have used silicone lightly on both flange and seating area.

So far no leaking events and I have used brand new T valve gasket even old wasn’t in bad shape or hardened still replaced it with new.

[engnr.mubashir]

@Xulfiqar sir need guidance on how to flush cooling system of 11th gen gli before adding coolant to the system and what ratio of coolant is 50/50 or 30/70.
Should I follow citric acid procedure as I have done that on my cultus EFI using your flushing procedure followed by soda bi carbonate for neutralise acidity of citric acid.

[Xulfiqar]

its the same procedure. make sure to have a hose pipe connected to a tap or something to push all acid out from the engine, radiator, heater etc. before doing the final fill and drain with RO/Distilled water and final fill of coolant.