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Old 12th June 2019, 13:19   #11
Randyjim
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Remove the radiator breather hose, either from the corner of the radiator, or the neck of the expansion tank and see if the level drops back to where it should be.

The breather pipe in the neck of my expansion tank used to block frequently. I suspect it had a bad drilling with some 'toilet seat' swarf as I never actually managed to dislodge anything. I've changed the tank now and the level has stabilised.
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Old 12th June 2019, 13:47   #12
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i removed the bleed screw but did not raise the tank as i did not know you had to.
filled until water came out of the bleed screw,then refitted.
filled tank to just under the neck .
started car.
ran on tickover until water was pushed out from tank then fitted lid.
ran on tickover until fan ran.
In total the car ran on tickover for 1 hour aprox .
turned off and checked next day.
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Old 12th June 2019, 14:15   #13
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Quote:
Originally Posted by Randyjim View Post
The breather pipe in the neck of my expansion tank used to block frequently.

It does, but it doesn't prevent the head bleed from working. There's a larger drilling from the same pipe hidden to the left of the neck.


This view from inside the tank shows both holes. Number 1 is the small drilling in the neck which gets sealed off by the pressure cap o-rings. The No.2 hole is the main bleed outlet.




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Old 12th June 2019, 14:25   #14
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Originally Posted by 190+ View Post
i removed the bleed screw but did not raise the tank as i did not know you had to.
Here's what RAVE says about refilling the KV6. It's from an on-line graphics to text service.

(The lower hose has been disconnected to drain the system).

1. Reconnect bottom hose to radiator and secure with clip.
2. Clean cylinder block drain plug and apply Loctite 242 to first 3 threads.
3. Fit cylinder block drain plug and tighten to 20 Nm.
5. Release expansion tank bleed hose from clip on top hose.
6. Remove bolt securing expansion tank and release tank from location in radiator.
7. Prepare coolant to required concentration.
8. With assistance, raise expansion tank to maximum height hoses will allow (approximately 125 mm).
Caution: When raising the expansion tank, ensure that the plastic hoses do not become kinked.
9. Fill cooling system, keeping coolant to neck of expansion tank until a steady stream of coolant is emitted from bottom hose bleed screw hole, then fit and tighten bleed screw.
10. With expansion tank still raised, continue filling until coolant reaches expansion tank neck and remains static.
11. Lower expansion tank and locate to radiator. Fit bolt and tighten to 5 Nm.
12. Secure expansion tank bleed hose in clip on top hose.
13. Fit engine acoustic cover.
14. Ensure air conditioning is switched off.
15. With expansion tank cap off, start and run engine, at 1500- 2500 rev/min. Fill expansion tank as necessary to maintain coolant level just below expansion tank neck. When coolant starts to rise up expansion tank neck, due to heat expansion, fit expansion tank cap.
16. Continue running engine at 1500 - 2500 rev/ min until cooling fan comes on, then run engine at idle speed until cooling fan stops.
17. Switch off engine and allow to cool for 30 minutes.
18. Check cooling system for leaks.
19. Remove expansion tank cap and, if necessary, top-up coolant to MAX level. If MAX mark is not visible, remove excess coolant until level Is at MAX mark.
20. Refit expansion tank cap.
21. Fit underbelly panel.
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Old 12th June 2019, 15:55   #15
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Quote:
Originally Posted by T-Cut View Post
It does, but it doesn't prevent the head bleed from working. There's a larger drilling from the same pipe hidden to the left of the neck.


This view from inside the tank shows both holes. Number 1 is the small drilling in the neck which gets sealed off by the pressure cap o-rings. The No.2 hole is the main bleed outlet.




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It does if the route to both of those holes is blocked.
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Old 12th June 2019, 17:53   #16
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Indeed, but the hidden hole has the same bore as the head bleed pipes and is permanently open. There's no reason why it should block there than anywhere else in the line. In fact from all the reports I've read, this hole has coolant flowing through continuously with the V6. When the cap's in place, the much smaller neck drilling is permanently closed and stagnant. A dead end for debris to accumulate, which it does pretty often.


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Old 12th June 2019, 19:34   #17
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But it does block, so is worth checking. It only takes a minute to at least eliminate it as a problem.
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Old 12th June 2019, 19:45   #18
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Quote:
Originally Posted by 190+ View Post
i removed the bleed screw but did not raise the tank as i did not know you had to.
Well as you now do know, I'd try again if I were you following the MG Rover procedure posted by T-Cut earlier.

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