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Tips

Running unpressurized?

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Baz

Baz

Yoda
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I thought I found the coolant leak, then I didn't. Well now it is the tiny thermostat by-pass hose that runs from the pump to the head.
I really don't have time tonight to go through all the drama of getting to it (have an early start tomorrow to a car show 97 miles away) and I was thinking of running without the cap on the expansion tank.
Can I get away with it?
 
Maybe it'll be OK. The pressure created by the cap moves the boiling point "up" but presumably you're not running close to boiling anyway. I would fit the cap "loose" just to keep the radiator fluid from sloshing out.

The bypass hose you're talking about is a real annoyance in the Mini world as it's nearly impossible to get to. The accordion emergency hose has a terrible reputation. The fix most people propose is to take a piece of 1/2 heater hose just shorter than the distance between the bottom of the head and the water pump, fold it in half and hold it folded with a pair of vise-grips. Put a little lube on the nipples and a tiny bit on the inside of the folded hose ends, then press the hose ends against the nipples and push as you release the vise-grips. Use worm type hose clamps that you can open completely to secure everything.
 
At a constant speed, The temp is between 1/3 and 1/2. Get to a stoplight, and it soon creeps up to the 1/2 mark, so I'm confident that's where it should be under normal conditions.
I did get to it, replaced the clamp; I'd foolishly put on a fuel hose clamp and it just wasn't tight enough.
I'll check it at the first stop in the morning, maybe a short day, maybe a great one.
Thanks Doug, I will bear in mind the tip about the heater hose though, when I get to that thing again, and I'm sure I will, I'll replace with such. Cheers.
 
It did it again, half way to a car show.
Kind of odd, because I've got 300 miles on it since the engine out, without other symptoms.
Clearly, when the thermostat is closed, this hose just doesn't cut it.
I tried running with the cap loose, and the engine temp rose to the 2/3 mark.
I guess I'll try and fight with this, because I really don't want the head off so close to the Ozarks.
What's a worm clamp?
Would adding a by-pass sleeve to the T'stat housing help?
 
Why would the head need to come off? I've used Doug's method to replace the hose before, and if you do not want to go that route you could also take the water pump off to replace it.
 
I just replaced the water pump, so any undoing of bolts and replacing of gaskets daunts me if it can be avoided.
I've just found a meter of 1/2" heater hose, so I'll give that method a good try.
I just remember how frustrating it was to get that accordian hose back on, and noted, it would be considerably easier with the hose already on, then head lowered on to it.
 
Even if you have to go a little short, you would be OK with a good gear drive hose clamp.
 
Tis a pain without removeing the head but not impossable at all.
 
New one's on. With heater hose and monster clamps.
I'll wait till it all dries out and give it a run.
If it's still leaking, I can only suspect the head gasket in that area, and I sincerely hope not.
 
...or your newly installed water pump gasket. You didn't use too long of bolts on it did you? Not that I would know about that from any sort of experience. :wink:
 
Well, if it is the head gasket BAZ, make sure you get one before you start. If yours is the 1275, you can have the head off in 30 min, no problem. One of the easiest engines ever made for that sort of thing. Check the head and the block over and go over it with a single edge razor blade to catch any bit you cant feel or see. Does yours run hot when on the highway or when you stop at idle? Mine used to run hot on the highway and I found that the lower radiator hose has a spring coiled inside it to keep it from collapsing and that spring had all kinds of junk on it restricting the flow.
 
I used the same ones that came from the old one.
I sealed both sides of that gasket with Permatex and it was torqued down tight for weeks before any coolant went into it, so it had plenty of time to cure.
Looking at the thickness of the rubber on the accordian hose, compared to the heater hose, it looks considerably weaker, and if it wasn't on 'just right' I can see how the slightest internal pressure can force a squirt.
I feel a lot more confident with this new hose though, gives the clamp something to dig into.
Great tip.
 
Thanks Alan,
I've learned my lesson about going into a generic autoparts store and asking for those.
 
Yeah - the blank look one receives in response is something to behold...
 
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