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 Posted: Mar 30, 2020 08:30AM
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US
Good advice. 

Regardless of whether your bypass hose (between the head and water pump) appears to be in good condition or not, replacing it when fitting the new pump is prudent.  Whatever you do, do NOT install the emergency repair "accordion" hose.  The heater hose mentioned by 6464 is the way to go.  

As for this being an easy job... I'd say that is true on cars with the 1-piece fan shroud.  I hate having to touch the fan or radiator on my Mk1.

Doug L.
 Posted: Mar 30, 2020 06:16AM
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The water pump removal and replacement is one of the mini's easier jobs. Just replace the short length rubber hose with a new equal length  heater hose if your head has one.

 Posted: Mar 29, 2020 01:35PM
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US
I have never tried running an engine with the t-stat removed and its cover also removed.  I don't know if what you observed is normal or not.  Regardless, while there are people and places who will rebuild water pumps... for most of us repair is by replacement.

See the link below to our host's catalog page discussing the various water pump types.
https://www.minimania.com/Classic_Mini_Cooper_Water_Pumps___Thermostats_page_16

Doug L.
 Posted: Mar 29, 2020 12:00PM
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Another update.  i got the top off the thermostat.  Damaged the thermostat in the process, luckily I have my spare.  I threw the spare in a pot and turned on the stove to test it.  The thermostat says 75Deg on it, it started opening at 50deg and was fully open by 65.  Either it's opening early or my thermometer is off, which is possible, it's old.  Either way, it would allow flow.  Just to test I bumped the engine with the top off the thermostat off, nothing came out.  So I fired up the engine, fully expecting a fountain of coolant, nothing.  It looks like the water pump is not working.  Is that something that can be fixed or is that usually a replacement?  If I cant fix it, I wont bother taking it off until I get a new one.
Thanks all for the help btw, now to figure out how to reset the emergency lock off for my brakes.

 Posted: Mar 28, 2020 01:27PM
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GB

The valve pictured (often mistakenly called a PDWA valve) is an emergency lock-off for either the front or the rear brake circuit.  If either end loses pressure a shuttle moves across in the body and isolates the leaking bit.

Balance front/rear is done by having a stepped bore in the actual master cylinder and changing the rear wheel cylinder bore size to match the application.

If you bleed the brakes improperly it isn't difficult to fire this valve and lock off the back end - it's also a total bugger to reset it...

 Posted: Mar 28, 2020 01:24PM
 Edited:  Mar 28, 2020 01:26PM
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US
Quote:
Originally Posted by Derek81
I just happen to have a 2nd one [thermostat] I can throw in  

The fan belt doesn't look like it goes to a water pump, so....where is it?

If you want a new T-stat, go to the local parts store and ask for a Stant thermostat for a 1970s GM (anything) (180 degrees is Stant #29358).  

That pulley between the engine block and fan is mounted on the water pump.

I defer to others regarding the brake valve.

Doug L.
 Posted: Mar 28, 2020 12:37PM
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CA
That is the brake system bias or proportioning valve. It limits the amount of brake pressure going to the rear wheels.
The attached picture shows which is which.

.

"Hang on a minute lads....I've got a great idea."

 Posted: Mar 28, 2020 12:11PM
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So I have an update.  I took my rad cap off and ran the car.  There doesn't look to be any flow in there.  I pulled the hose off the top of the rad and it was dry, doesn't look like water has been in there in a bit.  I'm waiting for the engine to cool down enough to get the thermostat out.  I just happen to have a 2nd one I can throw in.  
The fan belt doesn't look like it goes to a water pump, so....where is it?

Side note:
I am trying to fix my brakes, In the process of bleeding them, I get fluid out of the front two calipers, but nothing out of the back two.
Looking at the brake master cylinder (i think that's whats in the picture) i get fluid out of the left two lines, but nothing out of the right two.
Is that something a rebuild will fix or am i way off?

 Posted: Mar 28, 2020 08:32AM
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US
Non-functioning water pump

 Posted: Mar 28, 2020 04:32AM
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CA
Another option to check is the ignition timing - if it has shifted the engine may run hot.

.

"Hang on a minute lads....I've got a great idea."

 Posted: Mar 27, 2020 04:54PM
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Well the fan is installed correct. Try some of the other suggestions.

"Retired:  No Job, No Money, Wife and I!  Will travel anywhere for Minis"

[email protected]

 Posted: Mar 27, 2020 04:19PM
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US
As mentioned above, overheating could be caused by many different things.  you could try a drain and flush of the cooling system-you'd be amazed at the amount of crap that accumulates over time.  Antifreeze to water ratio should be about 1/3 antifreeze to 2/3 water.  Don't know if it would help with your overheating problem but I would secure the rad shroud to the radiator.  Looks like you're missing a fastener at the forward upper location.

 Posted: Mar 27, 2020 03:58PM
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CA
"...In my driveway it goes from cold to over heating in less than 10 min. …"

Stuck thermostat?

Non functional waterpump?

Blown Headgasket?

My $$ is on one of the first 2 guesses.  You should be able to determine which is which. (ie: Without a thermostat installed, see if you have flow--feel the rad hoses and heater hoses)

At worst you could REMOVE the thermostat and stick into a pot of boiling water and watch it open to verify proper operation.  Depending on the outcome, you can always run the car (in your driveway) without the thermostat, to then see if you have flow.

Others more well versed than I can tell you how to troubleshoot the waterpump.  I'm sure there must be a way.

  ~ 30 minutes in a Mini is more therapeutic than 3 sessions @ the shrink. ~

  Mike  Cool  NB, Canada   

 Posted: Mar 27, 2020 12:09PM
 Edited:  Mar 27, 2020 12:14PM
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Image Gallery
Here is a my fan
https://imgur.com/uvW3lus >


Here is my rad cap, it looks like its 15psi right now
https://imgur.com/ikajiO8 >


Sorry, I didn't put oil IN the intake, I put it in the "dashspot"
https://imgur.com/ikajiO8 >


The car has not overheated in the many years I've had it in the states.  It has just started within the past year.  I'm not sure what has changed.
I have the coolant in the radiator about 1 inch from the top.  I usually just fill it full and then let it over flow to get the level it wants.
I made sure its got the 20-w50 oil.
It over heats in my driveway, I'm not driving it anywhere, its not registered right now.  In my driveway it goes from cold to over heating in less than 10 min.  I have messed with the fuel mixture because it was so rich anyone riding in the car would smell like fuel after.  I took the idle up about 100 rpm because the car would die at stop lights unless i kept choke out a tiny bit.
Back in England I did take the thermostat out and put it in boiling water to check the temperature it opened, and all was well.  Granted that was 8 years ago-ish.

I hope it is as simple as turning the fan around.

 Posted: Mar 27, 2020 10:01AM
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US
also verify your temperatures....

A Harbor freight Infared Thermometer is a great quick way to point and shoot and see temperatures.
  Get the engine warmed up = andmonitor ..  Look at temps of the head = Front and back .. temps of the top of the radiator etc.
 
They should have simular temps all across with a working thermostat and flowing water.... 180- 190 - 200 alll fair.. Its when you start pushing over 220 that its really getting Hot.

 Posted: Mar 27, 2020 08:15AM
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I've found that most overheating issues are because the fan is installed backwards. Please post a photo of your fan.

"Retired:  No Job, No Money, Wife and I!  Will travel anywhere for Minis"

[email protected]

 Posted: Mar 27, 2020 05:29AM
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Quote:
Originally Posted by Derek81
I noticed it because coolent started coming out the overflow and the engine itself started to smoke due to the oil on the engine that I spilled. Any help would be great, as I'm trying to sell it before I move and I don't want to sell a faulty car. 

The smoke is not going to be from the engine itself being hot.  It is probably from oil dripping onto the exhaust pipes.

Boiling over can be caused by several things.  Start with the cheap stuff.  Inspect the fan (post a picture of it here showing the blade curvature).  Check the tension of the fan belt.  With the engine at temperature, measure the temperature of the thermostat housing and the radiator header tank.  Let us know what it measures.  

You can fit a higher pressure rated radiator cap.  The cap will NOT lower the operating temperature of the engine but it will delay or prevent it reaching boil over.

Don't overfill the radiator with coolant.  If you fill it to the top, it will burp out some coolant when you stop the engine.

If nothing is revealed in checking these things it might be a stuck thermostat.  A thermostat for a mid-1970s Chevy will fit and work fine.  (See this old thread link:  https://www.minimania.com/msgThread/111135/1/1/Thermostat_cross_reference )

The cap and thermostat are relatively inexpensive.  Once you get past that you move into more expensive components and more labor to change parts.  Again, start with the cheap stuff.





Doug L.
 Posted: Mar 26, 2020 08:45PM
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I don't think changing to a lower temp thermostat will not make any difference. I would change to a higher temperature thermostat. A Mini's cooling system is just adequate at best. Under what driving and atmospheric conditions is it over heating? Driving in stop and go traffic on a hot day its sure to result in over heating. Adding an electric fan is good for these conditions or you can always turn on the heater if need be.

 Posted: Mar 26, 2020 07:50PM
TK
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AU
added oil to the intake? what do you mean?

I'd start by changing the thermostat to 74 degrees.

overheating can be caused by lots of things, timing, running lean, collapsed exhaust, binding brakes, loose fan belt, incorrect radiator cap, stuffed radiator etc etc.......

 Posted: Mar 26, 2020 04:44PM
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I have a 1985 Austin Mini with the 1275 cc engine. Before I imported it from England in 2012 I had the engine rebuilt and the whole coolant system replaced. I'm now having the issue of the car overheating. I've added oil to the intake, replaced the coolant, changed the oil and filter. What else would be causing it to over heat? I noticed it because coolent started coming out the overflow and the engine itself started to smoke due to the oil on the engine that I spilled. Any help would be great, as I'm trying to sell it before I move and I don't want to sell a faulty car.