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MG MGB Technical - Average life of an oil cooler

I've had my '67 B for 38 years and it seems that every 8 years the oil cooler starts to leak. Sure enough, after driving the car last night, I opened the hood to check all of the fluid levels and saw a puddle of oil forming next to the oil cooler. Going back over my records, that span almost 4 decades, it seems that the cooler never lasts any longer than 8 years. What have others experienced? RAY
rjm RAY

Mine has lasted since the car was new, 1974. No trouble at all.
I am on my third engine and have over 200,000 miles on the car.

Steve
SK DeGroat

I have two B's on one the oil cooler is ten years old and the other thirteen years and no problem so far.
Iain MacKintosh

Hi Ray.,

The one in my 67 is original and no leaks. Can you give a little more information. Is this from a hole in the fin area or a crack around the fittings?

A vibration issue could potentially cause a crack, and a rock could potentially hit the fins. I don't see any other reason that this would wear out.
Bruce Cunha

Where are they failing? Is there impact damage or could the unions have been stressed when tightening the hoses?
Dave O'Neill 2

These have all failed where they are glued together at the tubes that run vertically on each side. The one that I have now is in use with the Moss thermostatically controlled system that uses 4 stainless steel hoses. There doesn't appear to be any excessive stress involved in the failures. It would seem that the bonding, between components, is breaking down over time. I've had this car in constant use in 4 different states and climates and am at a loss to explain the failures that seem to occur at 8 year intervals. Very puzzling. RAY
rjm RAY

Bruce, Steve, & Iain-
Are you using plain rubber hoses or stainless steel clad hoses?

Ray-
Could it be that the extra rigidity of the stainless steel clad hoses transmits more high frequency vibration, thus causing the separation?
Stephen Strange

For 30 years I ran the standard rubber lines. In '02 I installed the Moss thermostatic kit that utilizes the 4 stainless hoses. Same results with both setups. The stainless hoses are very flexible and don't appear to carry any additional vibration to the cooler. RAY
rjm RAY

Same oil cooler for 27 years.

I've had the engine out twice (once because I was an idiot, once for tuning) and both times I flushed the cooler through with petrol/gas and then left it to dry out. It took a few washes before the petrol/gas coming out looked clean.

I can't say this did any real good, but I will do it again when I get the chance.

John.
JW Prewer

35+ years on the oilcoller n my B with ss-hoses.
Joern-M.

Stainless steel hoses on bith my cars without problems
Iain MacKintosh

OK Guys, what are the advatages of stainless steel pipes on the cooler?

I have stainless steel braided pipes instead of the stock rubber ones on my brakes. These are down near the wheels in all of the debris and muck and it seems sensible to have ones that will stand some bad treatment.

On the cooler I use stock rubber ones. They don't touch anything to wear through and are unlikely to be hit by anything. Where they pass through the radiator surround there are big rubber washers so that isn't a problem.

I was told the brake pipes would improve the feel of the brakes, and they might have done but its marginal at best. In the case of the cooler it is the pressure release valve in the block that controls oil pressure, and so I can't see an equivalent argument.

I guess that the fuel pipes are braided and so there could be an argument for braided cooler pipes.

Happy to know the truth!

John.
JW Prewer

They're simply heavier duty item that should last the life of the car. I wish the oil coolers on my car would do the same! RAY
rjm RAY

Q: "OK Guys, what are the advatages of stainless steel pipes on the cooler?"

A: If you ever open a bonnet and see oil spraying from one of the rubber hoses because it has broken, we never again will ask for the benefit of a ss-pipe!
I´ve seen this twice on friends cars and cleaning the enginebay afterwards is the least problem you have after such an incident!
Joern-M.

As a matter of interest Ray whay oil pressure is your car running?
Iain MacKintosh

My car runs between 60 and 80 lbs. oil pressure. Until I installed my rebuilt engine, with uprated oil pressure relief valve spring in '93, my pressure ran at 60 lbs. It was eating up coolers at the lower pressure too. RAY
rjm RAY

Oh sorry that seems to bomb out that theory. Mine run at 60 as well without any problems and I assume that most peoples do as well.
Iain MacKintosh

SS pipe? Or rubber hose covered with SS braiding? I can't see the latter would last any longer, just look pretty, and you can't see them deteriorating.

Mine runs at 80psi with no problem ... so far (20 years).
PaulH Solihull

On my second cooler from new. The first one had to be replaced because the hoses froze to it.
Stan Best

The stainless steel pipes you guys are talking about must surely be stainless steel braided rubber pipes.

The engine vibrates, the oil coller is fixed to the body, a solid pipe would not work and would break in seconds. There must be movement and that means rubber pipes. MGAs had longer solid oil cooler pipes but still had a rubber pipe to the cooler.

The reason that brake systems have rubber pipes is because the wheel moves on the suspension, and the stainless steel pipes there are rubber ones underneath the stainless steel braiding.

Carburettor pipes too are rubber (braided) because of the engine movement.

Engine mountings are rubber because of the engine movement.

Someone corect me please if I am wrong!

I have the same rubber pipes I fitted in 1982 60000 miles ago. The only reason I am thinking of replacing them is to lower the oil cooler on longer pipes for better cooling now that modern petrol runs hotter than 4 or 5 star leaded when the car was new.

John.
JW Prewer

Hi,
I have a 1973 chrome bumper MGBGT which I have owned for five years. I met the previous owner only once briefly so I can't be sure what has gone before, but the oil cooler has started leaking oil. Mine seems to be where the inlet and outlet pipes are screwed on. I will be stripping it off in about six weeks time and will be able to more accurately locate the source of the leak then.
C.S. Barrow.

I think the cooler on the V8 must have been weeping when I bought the car 15 years and 80k miles ago as one corner was bunged up with black gunge. Cleaned it out, and of course it started seeping. Replaced it and it has been fine (so far ...) since. I also remember seeing one with hoses chucked in the corner of a car park at my son's uni many years ago, presumably bypassed by an impecunious student. You have to consider the time-warp, of the newer the part the shorter time it will last.
PaulH Solihull

The oil cooler thermostat and stainless steel braided lines are manufactured my Mogul in England. Moss sells it as a kit. The lines are, indeed, flexible. I installed the new cooler today and inserted 2 pieces of inner tube underneath it. I used the old cooler as a template. When I went to install the cooler I noticed that the pieces of rubber, that I had cut, were not straight. It appears that the old cooler had warped into a semi-horseshoe shape, from the front side to the back. My theory is that, when it heated up, the force of air across the cooler distorted the cooler over time. When it cooled off it was no longer under any pressure and eventually assumed the shape that it now has. Oh, the old cooler was marked made in England. The box the new one came in says made in China. They're identical in every way. The tooling must have been shipped to China to lower the cost of production from $120 to $70. I'll let you know how it holds up. RAY
rjm RAY

"when it heated up, the force of air across the cooler distorted the cooler over time."

I find that very difficult to believe. More likely that the mounting holes didn't line up, the bolts had to be forced in and heat expansion caused the bowing.
PaulH Solihull

Paul, The mounting holes lined up perfectly with the old cooler and the new one. The holes in the cooler base are larger than the bolts and allow for a fair amount of error. The bolts dropped right in when I installed the new cooler. I still can't find a logical explanation of why these units last only 8 years on average. Very perplexing. I took the car for a long run yesterday and it was a lot of fun putting the supercharger through its paces. RAY
rjm RAY

Stainless covered rubber = looks good, but functionally no benefit. What you might theoretically gain from protection of the braid, you lose through inability to see the rubber underneath deteriorating. This can be particularly so if the braid itself starts chafing on the rubber. This is why the braided brake lines are actually teflon reinforced.

Braid does sure look pretty though!
Curtis Walker

"I still can't find a logical explanation of why these units last only 8 years on average."

I can - so much current stuff is crap! What's more difficult to accept is that air pressure can bend the oil cooler. If it really did, then I'm amazed it lasted that long. If the holes on the old bent cooler exactly lined up with the new straight one, then that proves the holes on the old cooler were further apart from each other when it was new and presumably straight. Whether that put the holes out of line with the holes in the apron is a different matter.
PaulH Solihull

Not that more input is needed this late in the game, but my original cooler lasted until the 1990's when I made a mistake and broke it. I installed a new cooler from Moss at that time and it lasted ever since.

The cooler on my '67 is nearly 30 years old, running stainless hoses the whole time and no problems. Never had one fail on any of my other cooler-equipped cars either (MGA, MGC, BGT).

Maybe order one from Mocal or another reputable supplier instead of Moss?
Steve Simmons

Curtis-
The Teflon lining of braided brake hoses is not there as a reinforcement. Teflon lining has the advantage of being impermeable to air, thus largely overcoming the problem presented by the hygroscopic properties of most brake fluids.
Stephen Strange

Hi,

Stainless steel braided hoses are non permeable and resist many chemicals and temperatures, that rubber doesn't.
The construction is such that the braiding provides the strength to resist the internal pressure, whilst the teflon provides the impermeability. Unfortunately the teflon is quite fragile, if mistreated. Any kink will damage it with a very high risk of failure. Personally I would never use it on a car, too risky. Stainless braided rubber, on the other hand, looks good and has a higher resistance to abrasion and cuts, than straight rubber, but the tube that holds what ever fluid is still rubber.

Some years ago an Australian Navy ship had steel hydraulic plumbing replaced with stainless / teflon hoses, with a subsequent failure of the hoses which allowed the hydraulic fluid to escape and catch fire, killing 4 sailors. I dare say that the hoses where correctly assessed as to pressure rating etc, and were easier to fit than rigid plumbing, which would have been the rationale for replacement.

Herb
Herb Adler

Hi Ray,

You mentioned that you fit rubber between the cooler and the apron. I wonder if that could be the problem. Mine is bolted directly to the apron. The rubber may allow some vibration to be set up which eventually leads to the failure. Also mine pass through the radiator valence with a rubber grommet and have a clip bolting the two hoses together, about halfway between the radiator valence and the engine. My thoughts are that this clip and the rubber grommet may also act as vibration dampers. If one or both are missing then you could be getting some vibration in the hoses, which transmits to the cooler.
FWIW

Herb
Herb Adler

I installed the rubber under the new cooler on the advice of another poster to reduce vibration and increase the longevity of the new oil cooler. The rubber grommets are in place in the valence in addition to small pieces of heater hose that I used to make the thermostat a tighter fit. The first cooler failed in '75 followed by the failure of a used one several years after. The next one, purchased from Moss and made in the UK, lasted 8 years. The new one is identical to the last one, but the box says made in China. It appears to be made to a very high standard, probably made on the same tooling, and time will tell if the quality is, indeed, what it appears to be. RAY
rjm RAY

Ray I made two struts that fit between the top strap and bottom strap of the cooler and ran long bolts up thru both straps and thru the struts to mount to the nuts installed in the car sheet metal. this supports the cooler top and bottom to prevent any vibration in the unit. you may need a machine shop to make the struts so they fit well and don't cause any tweeks in the cooler frame. HTH
MLS Somers

This thread was discussed between 26/08/2010 and 12/09/2010

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