Topic

Reliability generally follows a bathtub curve for “stuff that works ok”. Coolant hoses are probably an example. MGF and TF cars are “not in the first flush of youth”. So, does anyone have experience as to what to expect?
In my case the car is a Dec 2002 build with pre PRT thermostat.
I am going to attempt to change the water pump and timing belt in the next few weeks as there is little history with the car (recently purchased) and it has done 85000 miles..
If I look on various web sites few seem to offer hose kits or parts for the pre PRT systems, and if I price up a modification to a PRT system it approaches £500.
So what experience do people have in this regard please?

There are plenty of cars running around without a PRT stat. Your money will be better spent on a low coolant level alarm. By all means give all the hoses a good squeeze and if you haven't stainless underpipes, fit them but if it ain't broke, disturbing it will probably cause it to need fixing!

Agree with the observation relating to disturbing a hose is likely to lead to problems or encouraging early failure of that particular hose. Clearly the original thermostat functions even if the PRT might be better.
The question I ask is more about life expectancy of the hose system not whether I should convert to PRT.
When I seek to price replacement hoses as a group it appears that most of the well known suppliers sell those hoses associated with the PRT system and not the early system.

So they must be doing that for good reason, and if a new hose is fitted to the old system (for example to renew the hose that is disconnected when draining the system to facilitate a pump change) and a subsequent failure in a different place occurs it would have been poor economics particularly if the item that failed is NLA.

So what I am seeking from members is a sense of where is the far end of the “bathtub curve” for hoses in these vehicles?

Everything is still available with a bit of guile and research. Fit a monitor and wait until something breaks. The bath may be half full or half empty but the slope is not dramatic, suggesting that many cars will not suffer failure.

Well with bath half full it just depends on whether you are trying to fill it or empty it!
What I’m seeking is to establish if one or more particular hoses are more prone to failure than another.
Example: if I squeeze one of the hoses attached to the underfloor pipes at the engine end it feels much softer than some of the others (or at least softer than those my MGB or the C that I sold some time ago,..

Under hydraulic test I would expect a hose to elongate if it is good. If it shrinks in overall length it suggests the inner mesh matrix has failed. Just saying!

As always there is no simple answer, in an ideal world you would pay the £500 and replace and update the whole system BUT as you say some are NLA. This leads on to the quality of what is available, NOS and if so how has it been stored? New after market, from a reputable manufacturer or not? I had the same question a few months ago and replaced a couple of hoses that had obviously gone soft the others will remain in place. Due to having had the engine out (still is!) due to the previous owner not checking oil levels! my replacement engine came with a complete set of hoses including the stainless steel ones that go around the engine, so I have a spare set. The rest of the hoses will not be replaced but a low coolant alarm is being fitted, I have used a VW expansion tank (better quality than OE) with a low level alarm wired in which has cost about £30 all in.
If you decide to replace all then you will need to source from several different suppliers, even then you will need to look on Ebay, it may take a few weeks but you will eventually find even the rarest one

The VW tank sounds interesting, in what way is it better?
And do you have a part number or precise model and model year for the part you used.
I presume (always dangerous) that you have it wired to an aftermarket buzzer or similar in the cab. Is that right or have you connected it to an existing instrument, and if so which one please?

Concerning full hose replacement, I saw something a while ago on the Facebook MGF and TF Enthusiasts group. A company called Stoney Racing does a full silicone kit for about £200 - 300. I have no first-hand knowledge of this so no details but Google will find it for you.

I have drained the system and replaced the PRT thermostat on my TF and that was awkward enough. Replacing the whole lot sounds like a labour of love.

I can highly recommend my low coolant alarm kit which I sell to members of The T-Bar for a significant discount.
https://www.the-t-bar.com/forum/31-for-sale/96870-mgf-and-mg-tf-low-coolant-alarm-kit
PM me for details

I’ve used a VW header tank for a number of years & unlike the original, of which I had two failures in quick succession I no longer have that to be concerned about.
However the low coolant system utilises current flow through the liquid so care has to taken when selecting an an appropriate alarm.
I’m fortunate in having a good (accommodating) scrapyard fairly close & I’m able to harvest parts from there; he has f & tfs on from time to time. There is no shortage of old 25s, 45s & 75s which share a number of GP parts. VW are well represented & most have similar spherical tanks like mine. It’s advisable to take the connector. Brew your own circuit, a comparator is ideal & YouTube will have loads of ideas for you to mull over. EBay has page after page of useful circuit boards & I’ve no doubt that you’ll be able to adapt something from there. M

Not exactly new hoses advice, but I have used 4Life (water free) coolant for years without issue, the benefits are a higher boiling point circa 180°C which in turn means less pressure, so kinder to old hoses, there is a chemical change when exposed to exhaust gasses (turns yellow from red) so early notice of some HGF's, its also good for 10 years so no need to change so often, ok its more expensive but hey ho, the down side is its more searching so your have to make sure all pipe clips are tight but that should be done anyway, as I say with fingers crossed, never had a problem in 10 years and still have enough at hand to change soon if I feel its necessary.

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Higher boiling point of 180 and less pressure? Twaddle, fiction and bosh! The coolant never reaches boiling point in a sound cooling system. That is the function of the pressure cap which raises the boiling point. If it does not open, and it doesn't, then you don't need snake oil.

Who rattled your cage? Im just stating what the manufacturer and respected members of a well-known club have suggested, I for one, have no reason to dispute the claims, if as you say the the cap fails that is when the water content would boil @100°C the chemical in ife coolant boils at 180° C therefore less pressure. You dont have to be obnoxious to get your point across. I was mearly giving my opinion and suggestions based on information and my own observation, should you believe different, then proof by evidence is the way to go not rude ranting coments, I apologise if my earlier post offended your sensibilities I was offering a fellow MG'er the benefit of my experience not asking to rudely responded to by such a supised know all.

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