Bypass hose

[Andyhereford]

A quick question. Wanting to replace the hoses on my daughters Minor. Can the bypass hose be removed / replaced without removing the cylinder head. When I replaced it on my Minor I had had the cylinder head off anyway. Thanks for any advice.

[philthehill]

The by-pass hose can be removed without removing the head by cutting it away piece by piece.
If the car is needed urgently fit a new convoluted hose for the present and fit a solid hose at a later date.
https://www.morrisminorspares.com/cooli ... ps-p829616
https://www.ebay.co.uk/itm/275403085107 ... R-7D2vnlYg

[ManyMinors]

Or just remove the water pump

[mogbob]

Or just remove the water pump

Plus Water Pump Gasket 88G215 , unless you're very lucky removing the pump temporally, leaving the gasket undamaged !
Bob

[philthehill]

If you decide to remove the water pump that involves removing the radiator so make sure that the four radiator mounting bolts can be undone.
The convoluted bypass hose can be changed in about 20 min total.
The convoluted bypass hose is not the ideal solution but it does get you out of a fix.

[Andyhereford]

Thanks all. I know about removing the pump, pump gasket, radiator, etc. thanks having done all of these things before.
I just wanted to know if it was possible to get the bypass hose, as sold by ESM, with the “concertina profile” onto the water pump / cylinder head connectors without removing either the cylinder head or the pump.
The suggestion is that it can …. so all well and good.
Sometimes there is a tendency, on this really excellent forum, for discussion to go off on a tangent? Best wishes.

[King Kenny]

With a corrugated hose it can be done but it is a bit fiddly and you need a lot of patience.

[philthehill]

When working in the BMC garage replacing the straight bypass hose on the classic Mini was a regular task and the convoluted hose was the most used for replacement. The access to the bypass hose on a classic Mini is much worse than a Minor and replacing it could be done without removing anything other than the old bypass hose.

[svenedin]

It’s a horrible job. The silicone concertina type hoses are very long lasting but in fact they are so rigid they do not really squash down so are almost as difficult to replace as a straight hose. Last time I did this I removed the radiator for better access. Even then there was bad language and I cut my knuckles

[geoberni]

Well here's a random fact for those who didn't know....
The original by-pass (according to the AKD3541) was the concertina type, but was superseded by the straight one....
.
.

by-pass.JPG (69.65 KiB) Viewed 7221 times

[oliver90owner]

The original by-pass (according to the AKD3541) was the concertina type, but was superseded by the straight one....

Operational (expected life before failure) or cheapness considerations? We’ll likely never know….?

Does say both were rubber back in the dim past.

[svenedin]

It’s the same diameter as heater hose actually so you can just use reinforced heater hose. I keep a piece of heater hose in the boot but I think it’s wishful thinking that I’d actually be able to fit it by the side of the road!

[rocco]

I fitted a new bypass hose last night after replacing a water pump, seemed like a good idea to me, but upon inspection of the hose I noticed that one end was cut flat and the other end was kind of dished.

I compared the old hose and it was the same. The best image I can find is this one:



So the obvious question now is which way around does the hose go? I've copied the last fitting and put the thicker walled end down against the water pump but it's left a load of space above on the adapter to the head. I couldn't see anything obvious that would signal which way to install it.

I suppose if it doesn't leak then it's not a problem but I'm till curious and before I fill the cooling system, I could still reverse it if necessary.

[philthehill]

The bypass hose in the picture above is the last type of bypass hose I would want to fit.
It is alright in an emergency to get you home but is not a long term solution.
The bypass hose should have straight/parallel ends with no difference in the wall thickness.
There is no requirement for the hose to have different ends as the water pump and head stubs are the same dia.
From your description it sounds to be not very well made.
A short piece of heater hose is much better than the bypass hose pictured.
The hose in the link below is a good acquisition but may need to be shortened to suit.
https://www.minispares.com/product/classic/AEG484.aspx

[rocco]

I was dreading you would tell me that Phil. I'll get a better one and swap it out again in a few weeks.

Do you think that type is designed that way to be able to replace in situ?

[philthehill]

Whether it was designed to be easily fitted/removed I do not know but having replaced quite a few over the years I know that the convoluted bypass hose is easily replaced even when fitted to a Mini and without any dismantling.
Way back the convoluted bypass hose seemed to be the only bypass hose available and they were not so flexible as they are now.
Only in an emergency would I now consider fitting a convoluted bypass hose.