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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - Oil flex line

P/no AAA627.

All the usual suppliers are selling this item too long at 335/40mm.

I have measured what I think is a suitable distance, giving sufficient length to flex, but not too long so as to cause excessive curvature (& thus failure). This length, end to end, including fittings is 280mm.

Can I ask a few people if they could check their flex line, firstly to check that it's not close to failing, but also to confirm the 280mm length?

Regards
Colin


Colin Manley

What oil flex line is that Colin!


Lindsay Sampford

Lindsay
That's interesting. Your photo is missing the braided flex line going from the block to a coupling on the starter switch bracket that in turn takes the copper line from the dual gauge. Your photo shows the copper line from the gauge going direct to the engine.

Thinking about it, and from a value engineering perspective, the set-up in your photo works, provides the flexibility needed and removes a common weak spot, so I see no reason not to do it.

Regards
Colin
Colin Manley

Colin, I have found what I think is an original type oil flex line. It came with my spare MGA engine and it measures 300mm or 1 foot fro the extremity of the brass fittings.
Lindsay.


Lindsay Sampford

Colin, you must have been posting at the same time I was! Yes, my car has been like that since I got it and the gauge line has not failed in the 20,000 miles I have done with the car. Doesn't look very neat though, I may consider going to a flex line if I can get one the right length; isn't that where you came in?!
Lindsay Sampford

Colin
Mine is definitely only about 290/300mm long. I bought it from Moss 2 years ago and it still looks in good nick, but then I'm a very low mileage man. I've checked and it's the same part number.
Plenty of slack in mine as you will see from the pic. So 335/340mm sounds much too long.

Graham


Graham V

I have asked one supplier for an end-to-end length dimension of the flex line. I have also asked another supplier to price making up one to the 280mm length.

If the 280mm price is unrealistic, and the length of the standard hose is still too long, I might reposition the coupling on the starter switch bracket to the heater shelf to reduce the curvature, and strain, of a replacement flex line.

regards
Colin

Colin Manley

I will have a look at my oil pressure flexy line tomorrow Colin and measure it for you along with the spare pipe I recently bought.

( If Graeme is listening, the answer to your question is "Yes I do carry it in my spares stash in the boot" and "No I don't have a spare, spare pipe!"😁

Colyn
Colyn Firth

I looked at mine just tonight again and though the curve was a bit exaggerated. I wouldn't go so far to think it'll fail, but it is a bit too long.
MAndrus

I had a search on the internet last night, and it appears that the MGB uses a similar pipe, AHH6554. The length of that one is 10". Would that be too short?
Lindsay Sampford

Don't worry about it. I have the same hose that is described as "too long" and it has been fine for at least fifteen years. It's predecessor failed because the staging of the hose to the end was not properly manufactured, not because of any strain on the hose.
Dominic Clancy

Colin
I have noticed that Brown & Gammon stock two. AAA627 and AAA627HQ with HQ standing for higher quality.
It may be worth giving them a call?

Graham
Graham V

Dominic,
Can't follow the "don't worry about it" route. I have had these fail on both pushrod & Twin Cam engines.

I have ordered replacement correct length 270mm high spec items from Stevson motors.

Regards
Colin
Colin Manley

Colin, which one did you order, SM245 or SM246?
Lindsay Sampford

Lindsay
246, the flex hose. It has a nitril core with additional canvas reinforcement, a cloth braid and the stainless outer. It is 10 & 1/2" long; the correct length for MGA. 10 year guarantee. Other suppliers have confirmed dimensions of their stock and they are too long.

Hope it arrives by Saturday, for Brooklands on Sunday; if not, I'll connect the copper pipe direct to the block. Of course, I would use my spare, but I already have!

Regards
Colin
Colin Manley

I rummaged around and found this pipe and it appears to be similar to the one in the image supplied by Lindsay but overall length is 285mm (to very end of each nut)

Mark


Mark Dollimore

My car is missing the adapter that attaches to the frame and the flexible that connects it to the engine. At the moment, the copper pipe goes directly to the engine, but I would like to restore it to the correct set up. Can someone tell me the correct routing for the copper pipe from the gauge to the adapter.
Lindsay.
Lindsay Sampford

Hi Lindsay
Firstly thanks for your help on bleeding the slave cylinder. Working fine now. I attach a few photos of the oil pressure route you requested. I have refitted the original steel pipe from the back of the dail to the brass connector to the flexi pipe. The pipe is coiled under the dash and then passes out through the original orange grommet. Then clipped to bulkhead and connects to brass link. Hope this helps.
Brian


Brian Paddon

More Images


Brian Paddon

Another in engine compartment showing clip and screw to the o/s of m/c assuming yours is RHD.


Brian Paddon

Last showing connection to brass unit and Flexi. I also used the original flexi to the block.


Brian Paddon

The outer steel mesh braid type lines are for fuel, at least originally they were-(Petroflex.) The oil pressure line coming off the engine was originally just like the MG TC (hard to find now) black cloth braid covering rubber, and then, steel spring type wire wrapped around it. MGA guru agrees. If they cannot get the appearance right now, why expect the correct length? What they sell probably fits somewhere on some other car, too.

http://mgaguru.com/mgtech/fuel/fu109.htm


D mckellar

Brian, thank you so much for going to all the trouble of taking those photos, it is much appreciated. I was not able to find any description of the way it went on this site or Barney's (he will probably come on here to tell me where it is now!). I was surprised that you said the pipe was steel; even though I thought it felt like steel, I had assumed it was copper. I just went and checked it with a magnet, and sure enough, it is steel. My pipe has been coiled on the engine side of the bulkhead, so I think that I will leave it that way, rather than trying to straighten it and risk it fracturing. Had the pipe been copper, I may have got away with it. I have the brass adaptor on its way from Leacy Classics and Stevson Motors are supplying the flex hose, so hopefully I should get the oil gauge line back to standard next week.
Lindsay Sampford

Lindsay, is it possible to carefully remove the pipe and turn it around so that the coil will be hidden under the dash and the straight part routed and screwed to the brass connector, via a clip on the bulkhead tray. I think the fixing nuts are the same each end.
Brian
Brian Paddon

Brian. That is certainly worth looking at. I think it could be possible if you are right in thinking both ends are the same, the existing coils will probably be in the right place for under the dash.
Lindsay.
Lindsay Sampford

Colin, I ordered the oil gauge hose part no. SM246 from Stevson Motors yesterday and it arrived today, very impressive. But guess what, it is 335mm (13.5 inches) long! Didn't you say that that part no. was 10 & 1/2 inches long? Have you received yours yet?
Lindsay Sampford

Lindsay
Yep, your right. Mine arrived and is longer than I was told over the phone. I have fitted it though, to get back on the road. It is a larger diameter than the previous line and 'lays' better. (Can't upload pic at the minute as software says the file is too large). You can also rotate the swages when the nuts are tight, so there is no spiral twisting loaded into the hose.

Regards
Colin
Colin Manley

Colin, thinking about it, 10.5 inches would be too short. That is about the distance from the block to the adapter as far as I can tell (I don't have the adapter yet). The hose that came with my engine was about 12 inches, so these new hoses are only 1 1/2 inches longer. I think they will be just fine, and those other hoses were failing because they were rubbish!
Lindsay Sampford

I wonder if there is a reason why MG did not use the steel braid fuel line construction rubber hose for the oil flex line? Up until not too many years ago the correct style rubber flex line was commonly available from places like Moss, etc. Maybe if people started asking for the correct style hose (as originally supplied) suppliers would start offering it again.

To quote Barney the mgaguru from the above link:

"" As a side note, the smaller flex hose on the other side of the engine for the oil pressure gauge signal line was also originally a Smiths hose. Modern replacement parts commonly have construction similar to the fuel hoses with stainless steel braid covering, but original parts were much different. The original oil pressure hose had cloth braid on the outside of a small bore rubber hose, then had a steel wire spiral wrapped around it for protection and form holding (similar to the temperature sensor tube). One of the brass end fittings was stamped with the maker's trade name "Smith's Super-Flex". ""

D mckellar

Colyn,
Replacement oil line in place in photo.

Imagine photo rotated 90 degrees clockwise.

regards
Colin


Colin Manley

When I did my restoration and came to replacing the oil flex line it did seem a bit short even though it had been on the car for at least 20 years. It measured 10 3/8" long and seemed original with the yellow Petroflex band still around it. Anyway I was sufficiently worried to buy a new one which was longer but I didn't measure it.
Some years ago someone was advertising an original boxed Petroflex line for the MGA (part number PFP26)and I asked how long it was and was told 12.4" (315mm) (see photo)
........................Mike


Mike Moore

Mike, any Petroflex line is designed to be a fuel line. If the fuel line you got is the right length it is just a coincidence. "Petro" is short for "petrol" and not petroleum. The original correct oil flex line is quite different in appearance, despite the fact Moss and the other's are now selling a Renault Dauphine fuel line (Petroflex copy) as being correct for MGA oil flex line. Read the article by MGAguru and you will see-

http://mgaguru.com/mgtech/fuel/fu109.htm
D mckellar

Using low pressure fuel lines in place of high pressure hydraulic lines is just plain crazy. Don't do it. Some modern fuel hose is also built for fuel injection pressures, but just because a rubber line has stainless weave wrapped around it don't mean it is hydraulic pressure line.

That NOS petroflex somebody found is good for a shop that makes specialized fuel and pressure lines, so they can cut off and re-use the connector end fittings if they are some British odd threadform, but that's about it.
b fisk

You might notice that it says on the box, 'PETRO-FLEX unbreakable, armoured, flexible petrol & oil pipes'. Would it say '& oil' if wasn't intended to be used for oil? My MG midget had a similar braid covered oil gauge line and it didn't fail in the 200,000 miles we used it as a daily driver. Aren't lines that go to your oil cooler braid-covered rubber hose? We are only talking 60-70 psi, the sort of pressure you would find in a racing bicycle inner tube, not 100s of ponds.
Lindsay Sampford

The picture of the Petroflex oil line was taken from an Ebay advert many years ago. I didn't buy it.
I was interested because I wanted to know the original length.
At the time (maybe they still are) lengths of fuel and oil pipes for the MGA were all over the place.

I remember buying replacement fuel lines which turned out not only to be too long but were different diameters and had different style end ferrules. They didn't look right on the car so I discarded them and made my own...............Mike
Mike Moore

No Lindsay you are wrong. "Smiths" is the manufacturer's name. "Petro-Flex" is a registered trade name for their fuel hose products. Smiths did make replacement (and the original factory installed) MGA oil flex lines, but I believe they were trade named "oil-flex" but that name is going on memory. For sure the oil flex lines do not have the stainless sheath. Main point here everybody seems to be ignoring was brought up already and completely ignored. What you guys all work for Moss or something? The correct style oil flex line like we are talking about does not resemble petro-flex fuel line in the least bit. It is black with "armour" wrapped around like a stretched out slinky. Just like the already cited reference link to the MGA Guru article, see above at the bottom of article page. Anybody read it yet? Is it factually wrong?
b fisk

Fuel hoses running to the carburetors are big bore thin wall low pressure hose (5-psi). The oil pressure signal hose is small bore thick wall higher pressure hose (100 psi). External construction is cosmetic, some concern for concours enthusiasts.

clutch and brake hydraulic hoses work at much higher pressure (up to 500 psi). Steel braid on a brake hose is still cosmetic, and even illegal in some countries.

barneymg

the only "slinky" hose I ever fitted failed as soon as the engine was started. The old hose was reinstalled and replaced with the steel braided type as soon as it arrived - the reason there are no slinky hoses around is probably because the last batch made was of terrible quality!
Dominic Clancy

As Barney clarifies I am right I will move to my next point on this. With Moss and everybody and their brother in law peddling these stainless wrapped braid fuel lines, oil lines, brake lines etc that all look exactly the same, how is anybody to tell right from wrong? My nephew came by my shop to fix the sink last week and he brought a replacement supply line that foes from the shut off valve to the faucet. Guess what, it looked exactly like these flex lines everybody is selling for everything on a car. I do mean "exactly" the same, except for the compression and NPT fitting on each end. I guess that's why MG made the black rubber flex line with the slinky around it. and the braided steel flex line for the carb's; so you would be less likely to fit one specification hose where the other kind should go.

Yes Clancey I remember hearing about those bad rubber style slinky hoses, but that is no excuse for the Moss and everybody else peddling the wrong looking hose as accurate original. Same to Barney, why don't they just make the hose in the correct style? There is a reason why they were different, and when I pay good money for a oil flex line I want it to be not only functional but correct in appearance. If parts being sold there no reason only the coucours guyus get it right, I know you know that Moss and everybody else making these know the oil lines look all wrong. $$$
b fisk

To clarify a few issues, S.Smith & Sons(England)Ltd. was a parent company and their subsidiary companies included:
-Smiths Motor Accessories Ltd.
-British Jaeger Instruments Ltd.
-Petro-Flex Tubing Co. Ltd.
plus many others.
Petro-Flex manufactured both petrol and oil tubing. As stated and pictured on Barney's site, the Smiths Super-flex oil pressure hose was originally cloth braided with a steel wire spiral. However sometime late 1950's the design was changed to a steel braided version which was the same (at least externally) as the petrol hoses.
Referring to
htpp://mgaguru.com/mgtech/care/cf140-30.htm

the Smiths PetroFlex oil hose part number is PFP 195.
The attached photo is of an original oil hose from a 1959 mga twin cam and it can be seen that externally it is the same as the original Petro-Flex petrol hoses, that is braided zinc plated steel.


Garry Kemm

b.Fisk, I think it was unlikely that MG made the hoses - they where bought in from ...Smiths. The reason that Moss etc make the "wrong" parts is that no one will pay the price for good quality parts...
I get my oil pipe made up by pirtech, it costs more but they are correct for the pressures involved, maybe not concours but safer.
David k Brenchley

I have probably made my installation worse by fitting a T-piece at the gauge end of the flexible. I have fitted a pressure switch with a buzzer and power-on delay timer to instantly detect loss of oil pressure. Once bitten when the hose to the oil cooler failed.

And Colyn, would I suggest that?
Graeme Williams

So you had an oil cooler hose actually fail Graeme?

Wow, I have never heard of that happening before!

Just for a minute there I was wondering where on earth can I find space to stash a spare oil cooler hose? ( no crude suggestions please! 😁)

Then I remembered that I have an oil cooler thermostatic bypass in my oil circuit which is connected by four long (stainless steel braided) hoses.
So I would probably be able to loop one of the hoses back to the engine to bypass the oil cooler altogether in the even of a hose failure.

I do carry a spare flexy (s/s braided) oil pressure gauge hose in amongst my spares although I still haven't checked the length of it or the fitted hose yet.

Colyn
Colyn Firth

Colyn: the hose failed at the swaged fitting - it pulled out of the fitting. I heard an odd engine noise, just as the chap behind dropped back a noticeable distance (he must have seen the oil shower). I must have caught it just in time. I look at the gauges fairly often but even a couple of minutes running on no oil would probably be terminal.
That's why I now have a failure detection backup to sound a warning if pressure drops below 5psi.
Graeme Williams

Lindsay
The supplier sent the correct hose. Now fitted and a more graceful curve.

Regards
Colin


Colin Manley

This thread was discussed between 28/03/2017 and 13/04/2017

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