MGB coolant hoses

[AJB]

I've just bought an MGB GT. All good so far, but the top radiator hose and the heater hoses are looking a bit past their best. Having gone through the invoices which came with the car, the hoses aren't all that old (they're newer than my daily driver which has still got perfect hoses), so I'm guessing it's another case of aftermarket parts being somewhat iffy quality.

So, I'm thinking of just buying some regular high quality modern hose instead of questionable MGB specific hoses. Two issues:

Firstly does anyone know what inside diameter I need for the heater hoses and for the radiator hoses? I can't easily measure it with the old hoses on, and I don't want to drain the coolant until I've got the new ones ready to go on!

Secondly, although I'm fairly happy that a straight length heater hose will be able to bend to allow for the "kink" in the custom made heater hoses, I'm a bit more unsure about the top radiator hose. The custom ones are all concertina, and I'm wondering if that's to allow it to change length as the engine rocks on its mountings? Having said that, the expensive MGB specific silicon sets just have straight hose with no concertina, so that makes me think it might be OK after all. Any thoughts?

Thanks very much,

Alan

[Nigel At]

Alan no need - if it's a '72-'76 MGOC do a silicone kit

Silicone Hose Kit - 1972 to 1976 G382 [38]
Price: £89.95 Including VAT at 17.5%

see http://www.mgocspares.co.uk/acatalog/MGOC_SPARES_R...

or I can recommend - http://www.classicsiliconehoses.com/our-products/ plus you'll need rolled edged jubilee clips

the standard rubber hoses start to crack up within 6-9 months and despite what MGOC show in their catologue the kevlar reinforced kits the smaller hoses are standard rubber

As always if the car's new to you I recommend getting an owners Handbook -
http://www.mgocshop.co.uk/catalog/Online_Catalogue...

and doing a full and proper 36,000 mile service and use the car regularly even thro' winter

If you're changing the cooling hoses throughly clean out engine, rad and heater matrix as this will help with cooling and heating so you can use the car all year round (get the correct pressure rad cap, see owners Handbook)

Edited by Nigel At on Tuesday 30th November 14:21

[AJB]

Thanks for the quick reply! It's a 1971.

I was just thinking that even the Silicone hoses could be a bit of an unknown quantity (although probably a lot better than the rubber ones), as they're still low volume manufactured by an unknown source.

If I got some standard hose like one of these (which they make in pretty much all diameters):

http://www.semperflex.com/en/industrial_hoses/prod...

then I thought it would definitely last ages! I've bought their fuel hose before for my previous old car, and it felt just like new car OEM quality, unlike the stuff sold by specialists which felt like a fire waiting to happen!

I've got a handbook for the MG (admittedly the upto 1969 one, but I imagine it's pretty similar), and the workshop manual. I'm planning to do the initial servicing on a rolling basis over the next little while. Have already checked/topped up all the levels, proper cooling system overhaul next on list. It needs a new thermostat too as it's running cold (unless the gauge is lying to me). I will change the various fluids before too long though.

And yes, I'm planning to use it! I'll try to avoid most of the salt, but I took it out on Sunday evening and froze myself trying to get some good photos of it on the top of a hill at sunset.

Thanks again for the advice,

Alan

Edited by AJB on Tuesday 30th November 15:55

[perdu]

the hose kits that Nigel has mentioned have been in "service" now for a long time

I havent heard any horror stories about them and I have heard plenty of the same, ref modern antifreeze mixtures and the old style ones.

I rather think (although I haven't looked) that MGOC are not the only regular suppliers of this type of worthwhile upgrade

Maybe a look in eBay could return a benefit or two

[Nigel At]

The silicone from Classic Silicone Hoses are thick triple-ply and I don’t expect to need to change them on my Midget plus they are the right shape and more likely too long rather than too short, I’m happy to recommend them

I'd still get the correct Handbook as the small differences can be very important best £8 you’ll spent on the car IMO

I’d still suggest you get a full and proper 36,000 mile service done as soon as possible, unless you’ve very lucky you’ll find out why as you go along plus a full and proper service will really help the car and is the best tuning you can do on it, changing all the fluids (unless you can prove 100% that any have been changed very recently

I’d check with other BGT owners that actually use their cars thro’ winter before changing thermostat, thoroughly cleaning and flushing (forward and back flush) the engine block, rad and heater matrix may help resolve this (as well as sealing draughts)

You should have a 10lb rad cap

Allowing for salt, use the car at least for a 30-50 mile return journey at least every couple of weeks and things will improve (if only because the faults become obvious)

Do you know about the ‘donkey’s dick’? – do a Search here

Good luck, loads of info here – http://www2.mgcars.org.uk/cgi-bin/gen5?runprog=mgb...

Edited by Nigel At on Tuesday 30th November 16:28

[Nigel At]

Oh just thought, heater valves can sieze up with lack of use - lift the bonnet and check that the value is fully open when the knob shows HOT

Using the car will also stop other components seizing up - cluthch, brakes, windscreen wiper, horns, etc.

[AJB]

Thanks again! The reason I'm thinking of changing the thermostat is that the temperature gauge sits half way between Cold and Normal, not because the inside of the car isn't warming up (although it doesn't get very hot in the car either). I'm assuming that's not right? Or is that normal for MGBs? I'm also making the assumption that the gauge is less likely to be failing than the thermostat (it's the sort with a small pipe from the dash to the engine, rather than an electric one).

Yes - I take your point about servicing. I guess I'm just holding off a little to see what else needs doing at the same time. EG I don't want to change the coolant, and then discover it needs a new thermostat and new hoses - I'd rather do that all at once. I have checked all the levels though (including diff & gearbox), so at least I know nothing is running dry. But I do know it all needs doing sooner rather than later!

Plus I do prefer tinkering little and often rather than having to learn everything at once!

[Nigel At]

well a gauge is a just a gauge, as I said check with other owners first

as long as you test your present anti-freeze is it's still working then of course it's a job best done in warmer weather, if your engine has been reconditioned then I'd recommend 4-LIFE rather than antifreeze and water (tap water isn't the best thing to use anyway) - don't forget to flush, back flush, clean and flush again rad, heater matrix and engine block

do service things as soon as you can to prevent faults and breaks

brake fluid is most important of course

changing the oils is simple and well worth while, engine (and filter), g/box (O/D) and rear axle

things like changing rotors arms (see Distibutor Doctor), dissy caps and HT leads (as part of 36k service) can help a lot

Check the age of your tyres if they are 5 years old or more replace ASAP regardless of tread depth (no need for wider or lower profile than standard or equivalent)

Good idea to use your car and learn what needs doing first, or what is normal, but have it at least a year before doing any cosmetics or "improvements"

Good luck, keep asking and learning, don't be put off by fair weather users

[mgtony]

In the summer I had a kevlar reinforced hose split along its length, not sure of the purpose of the kevlar! Happenened to be at my MG garage at the time, so replaced it with a standard rubber replacement. The next day I was at MG Live at Silverstone and picked up a hose kit to keep in the boot as spares.
I looked for silicone ones to see what was about, but couldn't see much at the time. Those links are useful Nigel. (Am I sad for wanting them in red or blue? )
If you were making hoses up, would using T joints and reducing joints to achieve the design of the bottom hose, have and negative affect to using a one piece one?
If it's any help, the main top and bottom hose is approx 29mm internal diameter, and as said, the bottom one tees off to a smaller hose.

[Nigel At]

Tony
- I got my Classic Silicone Hoses hoses on a visit to the Silverstone Classic in July 2009 they were just about starting up as a going concern then

I saw them at the NEC CMS this November too

If you contact them I’m sure they could make another colour

Alan
- I've just remembered (but details are still vague to me) when I had my ’74 BGT someone loaned/gave me a rad blind (fitted to front of rad grille and had two roll down openings) but for some reason I could get on with it so I made up a cardboard rad grille cover and painted it to waterproof it

It worked – the car overheated, that’s when I discovered a previous owner had put a 7 instead of 10lb rad cap on

If your car checks out OK then perhaps you could look at buying one of these rad blinds or making one up

[AJB]

mgtony said:

If you were making hoses up, would using T joints and reducing joints to achieve the design of the bottom hose, have and negative affect to using a one piece one?
If it's any help, the main top and bottom hose is approx 29mm internal diameter, and as said, the bottom one tees off to a smaller hose.

Thanks! Yes, quite possibly extra joints in the bottom hose would be a bad thing, although I think from the parts catalogues mine would originally have had an elbow and 3 separate hoses. Either way, it's currently got a one piece one which seems fine - it's all the other hoses which don't seem fine!

[AJB]

Nigel At said:

If your car checks out OK then perhaps you could look at buying one of these rad blinds or making one up

I was hoping it wouldn't need one of them - as in if the engine isn't hot enough, I'd have hoped that a working thermostat would shut completely and the radiator won't be doing much anyway. But I've never had anything with an oil cooler before, so maybe that changes things and it does need a blind for cold weather...

Or maybe it's all fine, and it's just the gauge that's wrong... In my experience thermostats don't last forever, so that's why I'd thought that was the most likely cause. I'll reconsider though! Thanks again!

[Nigel At]

Up to you of course Alan but buying a good quality preformed set would be the answer to me - I like fit and forget (and 4-LIFE for at least 10 years, 20 years in my mate's Supra)

And loosing a hose can also lead to loosing a head gasket and more

I'll preach no more but say that my BGT, previous Spridget and present Midget were/are, all along with a few other classics, used for daily driven, work, holiday and touring so I can strongly recommend preventative measures asap rather than (and I've had many, many) roadside, home or specialist repairs

good luck, drive and enjoy

[Nigel At]

Sorry Alan I missed your post above before

Good point about the oil cooler I’d forgotten about it – I’ve never been quite sure that a B needs one in this country unless it’s a track car or towing something heavy, as it sits just in front of the rad covering the rad grille will warm both

Different car and engine but as the water temperature gauge stopped working on my present Midget I had to replace the combined oil pressure and water temperature gauge for a brand new unit and both gauges showed the same readings, where I expected on the water temperature but higher than I expected for the oil pressure

Yesterday on the open road the water temperature showed just a bit off C (about 140 F) and even in the summer it’s well before the N (about 160 F) – this is about correct for a my Midget

Even yesterday there was still plenty of heat from the heater but your B has a fresh air flap that can be (cold) draughty

Have you found out why the ‘donkey’s dick’ can give you and your passenger wet legs (?) – a little test of knowledge that even some long

[AJB]

Nigel At said:

Up to you of course Alan but buying a good quality preformed set would be the answer to me - I like fit and forget (and 4-LIFE for at least 10 years, 20 years in my mate's Supra)

And loosing a hose can also lead to loosing a head gasket and more

Completely agree - and I'm the same - I want to fit and forget! I was just wondering whether high quality modern OEM type hose from a big manufacturer might be more consistenly fit and forget than a silicone set made by an unknown small company. Useful to have your recommendation for that supplier of silicone hoses though, so silicone might be a safer bet than I'd thought. More thought required!

Nigel At said:

Have you found out why the ‘donkey’s dick’ can give you and your passenger wet legs (?) – a little test of knowledge that even some long

I tried searching for it earlier as you suggested, but pistonheads search was broken. But I've googled it just now, and google did the trick! Will check that out next time I'm lying on the garage floor!!!

Nigel At said:

good luck, drive and enjoy

Thank you, will do, and will do!

Edited by AJB on Tuesday 30th November 21:57

Edited by AJB on Tuesday 30th November 22:02

[Nigel At]

AJB said:

Nigel At said:

Have you found out why the ‘donkey’s dick’ can give you and your passenger wet legs (?) – a little test of knowledge that even some long

I tried searching for it earlier as you suggested, but pistonheads search was broken. But I've googled it just now, and google did the trick! Will check that out next time I'm lying on the garage floor!!!

Until you can get under the car you can also try useing a long wire or thin stick and warm water from the air intake grille to check that it's not blocked solid

Wise at any time but especially now check your battery(s) and main live and earth terminals and connections are clean, secure, in good condition and protected - major cause of breakdown call outs even for modern cars and you have an old car with remote battery(s) location

There is no reason why a B shouldn't be extremely reliable (given a bit of time - and a bit of money)

[Nigel At]

Just been remided that you can get an oil cooler thermostat which sounds a good idea to me

[davey sprocket]

Nigel At said:

AJB said:

Nigel At said:

Have you found out why the ‘donkey’s dick’ can give you and your passenger wet legs (?) – a little test of knowledge that even some long

I tried searching for it earlier as you suggested, but pistonheads search was broken. But I've googled it just now, and google did the trick! Will check that out next time I'm lying on the garage floor!!!

Until you can get under the car you can also try useing a long wire or thin stick and warm water from the air intake grille to check that it's not blocked solid

Another new B GT owner here but mine isn't likely to see the road for a while as it's a bit of a project.
Am doing plenty of research while its too cold to play outside, however I'm getting frustrated by you guys keep mentioning the donkey's dick thing as when I search, I just come up with the same cryptic threads, where people allude to some mysterious problem but never actually give any details what it is!
Can someone post a link to something useful?

[AJB]

davey sprocket said:

however I'm getting frustrated by you guys keep mentioning the donkey's dick thing as when I search, I just come up with the same cryptic threads, where people allude to some mysterious problem but never actually give any details what it is!
Can someone post a link to something useful?

This is what I managed to find on google. The 2nd post on this page:

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Coming back to my original post, does anyone know why the top radiator hose is corrugated in the stock kits, but not in the silicone kits? Are the corrugated ones smooth on the inside (so the corrugation just makes them more flexible I guess), or are they corrugated on the inside too (in which case I imagine they could change in length as the engine rocks - although then how would the silicone ones cope with the engine rocking?)

Edited by AJB on Wednesday 1st December 22:47

[MG Mark]

The donkeys dick thing is probably the drain tube and rubber bulb that drains the vent area on the scuttle between the bonnet and windscreen (the fresh air intake for your ventilation) which gets blocked over tie with l;eaves and general rubbish. When it does,the overflow then comes through the ventilation system onto the legs....

A few random tips on the thermostat/oil cooler/hose exchanges above:

1) Where your temperature gauge sits is about right on an MGB - a tad below normal.
2) If you remove the oil cooler, irrespective of track or road use, the oil will run hotter and thinner, about 10-15 psi lower than normal, and the water temperature hotter - its there for a good reason, so best left in place.
3) On hoses, the proper original black rubber ones on my MGA (same arrangement) have lasted for 10 years+ and still look good - you get what you pay for, buy good quality. A spare set carried in the spare wheel dish gives peace of mind.
4) Fit a decent water pump - not the usual replacement with a four bladed plastic paddle thing, but one with a proper cast, curved, 8-bladed impeller - all parts of the engine will be cooled properly by a decent flow of coolant.
5) Make sure that the foam closing strip is fitted (as original) to close off the gap between the the radiator shroud and the bonnet - prevents hot air recirculating from the engine bay through the radiator. Again it was put there for a good reason, to maximise the cooling capacity of the radiator in hot weather, but they are often missing.
6) The original heater system in the car is completely rubbish by any standards, let alone modern ones. Upgrade by fitting an upgraded heater matrix. Or wear warm clothes.
7) In the likes of the current very cold weather, I have previously experienced ice forming in the bottom of the rad even with the engine running which starts blocking the tubes, resulting in the bizarre experience of coolant boiling over in freezing weather. A radiator blind (piece of cardboard tie-wrapped to the grille will do) to cover off part, not all of the grille, works if the car is simply not getting upto temperature.
8) By all means fit a lower temperature opening thermostat in summer, but it simply means that it takes longer to get up to temperature in winter.

MG Mark