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Old 24th November 2020, 13:07   #11
SD1too
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Then, raised the header tank, using a block of wood ... Got it up to temp ... I then switched off, undid the bleed screw in the top hose that leads to the thermostat housing ..
Hi Robert,

What you did there is not the official MG Rover procedure. The bleed screw should not be removed with a hot engine.
(By the way, the bleed screw is actually in the bottom radiator hose. )

The coolant you found under the thermostat housing will almost certainly be from the flattened 'O' ring seal. I'm afraid that these seals will have to be renewed because with a leak there you will continue to experience cooling system problems, albeit not major ones.

Your radiator fan appears to be in proper working order. You heard the slow speed when it started running at a coolant temperature of 100°C. What happens after that depends whether or not you have a resistor system. If you'd like to confirm which I can tell you the temperatures at which the various speeds operate. On your KV6 a resistor system has 2 speeds and a non-resistor system has 3 speeds.

Simon
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Old 28th November 2020, 19:42   #12
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Hi Simon, thanks for the info! I did do some reading up before attempting to bleed the system.

I've attached a picture "borrowed" from another forum of the bleed screw I loosened.

Having dried the thermostat area out (haven't really driven the car since bleeding it) and no coolant has appeared since so not sure what's going on unless it's a leak that comes and goes maybe?.

Anywho, if the bleed screw in the pic isn't the correct one, where would I find the bottom hose bleed screw you speak of?

At the present time, the car is parked up on the drive while awaiting funds to become available. On the list is the timing belt and aux belt and tensioner and thermostat kit with clips.

The temperature/fan thing. I couldn't get the engine to go above 100°c as soon as that fan kicked in, the temp dropped and fairly quickly too. Possibly due to air getting into the system perhaps? Despite being no leaks at the time of trying to bleed it.

Thanks and sorry for the late reply.

Rob
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Old 28th November 2020, 19:49   #13
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Hi Rob,

If you have water around the stat you will need that repairing, also the low speed fan needs to work as this is key to the cooling system functioning as it should.

Get those two issues sorted, bleed it correctly and ill bet you wont have another issue.
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Old 29th November 2020, 03:22   #14
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Thanks trikey.

I'll have a read about in regards to how to know if the low speed fan works or not as I tried with the AC running and then with the AC off but coolant temp causing the fan to run hoping the AC and cooling fan would operate at different speeds but couldn't notice any difference in fairness.

Thanks
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Old 29th November 2020, 08:10   #15
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Hello Rob,

That is the correct bleed screw (there is only one!). Here is the MG Rover procedure which you should follow exactly in future.

Quote:
Originally Posted by biffa75 View Post
Having dried the thermostat area out ... and no coolant has appeared since so not sure what's going on unless it's a leak that comes and goes maybe?.
It will trick you into thinking that you have cured it but then re-appear later.
Quote:
The temperature/fan thing. I couldn't get the engine to go above 100°c as soon as that fan kicked in, the temp dropped and fairly quickly too.
Be pleased about that, it's how the cooling system is supposed to work!
Regarding fan operation with the air conditioning, have you carried out the "demist test"? Start the engine from cold and press the windscreen demist button. Now get out of the car, walk to the radiator grille and please let us know whether the radiator fan is running continuously.

The fan uses the same speeds for both coolant temperature and air conditioning. For the latter it runs continuously and for coolant only when needed. I hope that helps.

Simon
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Old 29th November 2020, 12:39   #16
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Hi Simon,

Thanks for the reply, I will follow the correct procedure in future! (Honest )

Yeah I think will rear it's ugly head again, leaks usually do from previous experience. I'm planning on ordering a few bits soon as the little one loves the rover and wants to go out in it every time we go anywhere!

I have this morning, taken the gril out and the small plastic piece behind the grill to have a good look at the fan and found no resistor so believe my fan is the later 3 speed non resistor type?

I did exactly this test and found as soon as I hit the demist button and Aircon on the fan kicked into life and with a stop watch timed how long the fan stayed on.. it stayed on for over a minute and still didn't turn off (engine started from cold)

So can only mean the fan is working as should be I take it? Little bit hard to tell if it's running at full speed or if it's at low speed, the only thing that makes me think it's running as it should be is the fact that it didn't turn off after 30 seconds and then spinning back up and then turning off again, it stayed on continuously which I'm hoping is correct.

Thanks
Rob
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Old 29th November 2020, 12:40   #17
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To add to my last reply, the cooling fan when trying to bleed, came in at bang on the second the ipk displayed 100c and stayed on for maybe 2 minutes at a guess before turning off again when the temp dropped to around 95 or just below.
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Old 29th November 2020, 13:34   #18
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To add to my last reply, the cooling fan when trying to bleed, came in at bang on the second the ipk displayed 100c and stayed on for maybe 2 minutes at a guess before turning off again when the temp dropped to around 95 or just below.
Excellent.----
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Old 29th November 2020, 14:40   #19
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Rob,

Please be assured that your fan is working correctly. Yes, it's the earlier 3 speed type and will run at speed 1 when either the coolant reaches 100 degrees or the air conditioning is switched on. In the case of the air conditioning it will run continuously. If it ever stops doing this you will be able to look forward to fitting new motor brushes (usually at about 50,000 miles).

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... the little one loves the Rover and wants to go out in it every time we go anywhere!
Fast forward 20 years and picture your little one in a motor museum saying:
"My Dad had one of those".



Simon
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Old 29th November 2020, 16:20   #20
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On from Simon's post above, the change in the fan motor brushes will be as in the two pics below.-----
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File Type: jpg R75 fan brushes..jpg (120.1 KB, 9 views)
File Type: jpg R75 dead fan brushes..jpg (50.5 KB, 9 views)
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