Weeping oil cooler? Or the hose?

[deilenberger]

I'll take some photos later and post them.

Noticed today whilst out riding that I had some oil smear on the starboard side of the engine, coming from the front. Since I just changed the alternator belt a week or so ago, my first fear was an engine seal.

Happily - it isn't.. but it isn't too clear exactly what has started weeping. I looked more carefully when I got home, and spotted oil - wet oil - on the hose going to the bottom of the oil cooler (starboard side) where it mates to the cooler. After waiting for the exhaust to cool off, I took the shroud off the cooler and took a better look.

I spotted some oily bits on the bottom mount for the cooler to the engine. This is an angle bracket welded to the bottom of the cooler and mounted into the plastic cover for the alternator belt. There was also a drip of clean oil under the end of the hose where it went to the cooler fitting.

The hose is fairly short and stiff, and uses a one-time use crimp-clamp. My thinking at the moment is perhaps I stressed it when I dismounted the cooler (and left it resting against the rear of the front fender, but supported primarily by the hoses) to access the alternator belt.

I think my plan is to visit an auto parts store and see if they have any 21mm x 3mm fuel injection clamps (full circle clamps, not just threaded/slotted clamps) and try replacing it to see if that stops the leak. The other end of this hose is in a crimped fitting to a pipe that goes up to the cooling oil outlet from the engine - and costs about $150. There is no simple way to just replace the hose due to the crimped connection. If it isn't the hose fitting, then something on the cooler has cracked. Given how thick the metal on the cooler feels/looks, I am hopeful it's just the hose fitting.

Anyone else had a leak there? Mebbe it was hanging out with all the British bikes last week at the Gathering of the Nortons (an annual "celebration of the beginning of the riding season" - in the NJ/PA area. I don't know what a riding season is since I ride all year - but I like seeing all the bikes so I go every year..)

[dbrick]

Your idea to replace the Oetiker clamp first is a good one. If there's a flaw in the metal of the radiator, keep in mind that there are radiator shops who might be able to fix it instead of your replacing it.

But I think the current rubber hose to metal pipe crimped connection could be replaced with a FI hose-clamped one if it turns out there's a cut or other flaw in the rubber end of that assembly. Obtain a length of flexible rubber hose with an ID close to the OD of the metal pipe, looks like 8mm. Remove the metal pipe from the motor. Cut the metal pipe just above the current crimped connection. Clean and flush to remove all metal bits. Clamp the new rubber flexible hose onto the cut end and reinstall.

[deilenberger]

David,

Good idea.. but wonder what sort of hose can be used. Has to be oil and sunlight resistant. I'm a bit hesitant on cutting the metal pipe since there is no way to put the usual blister in the pipe (the expanded ID part that goes behind the clamp).. but on BMW cars, the power steering hoses are crimped the same way, what is done is to cut off the exterior crimp part, which leaves the barbed sort of inner steel pipe, and use hose clamps on them. Or try to find a shop that does high pressure hydraulic hoses.

Some photos will be along shortly.. I cleaned it up, and used my Oetiker clamp pliers to try to get more tension on the existing clamp. Will take it for a ride tomorrow and see if anything changed. Perhaps some talcum powder dusted on the suspect areas.

Dunno how well an aluminum radiator can be repaired... but certainly worth looking into (new one is $330.)

[deilenberger]

Some pics:

Overall view, there was a drip of oil on the bottom of the hose clamp. The crimped on end of the hose can be seen to the left:


Flash view from directly above:


Flash view showing the wet hose end, and the wetness above the mounting bracket (in about 1.5" from the hose end):


Closeup of hose and fitting. Note the oil in the crimp on the Oetiker clamp:


It's all cleaned up now, and will have to await a test ride in the AM. As mentioned, I slightly tightened the crimp on the Oetiker clamp - perhaps that may solve the issue.

[Lost Rider]

Dunno how well an aluminum radiator can be repaired... but certainly worth looking into (new one is $330.)

I've had radiators repaired and hold up very well, cost about $40 for this one straightened and the patching they did with some kind of special epoxy.
As long as that epoxy is oil proof I don't see why not, if that turns out to be your issue.




Before and after

[dbrick]

I'm a bit hesitant on cutting the metal pipe since there is no way to put the usual blister in the pipe (the expanded ID part that goes behind the clamp)...

I never thought of sunlight, but a little Googling found UV-resistant rubber hose in that size.

As to the missing blister: after cutting, clean the exterior of the pipe, then lay down a narrow ring of JB Weld around the pipe, perhaps 1mm proud of the pipe surface, located 5mm from the cut end. I'd rough the pipe surface a bit where the ring of epoxy will sit. The ring, the good clamp, and the lack of high oil pressure should result in the hose staying in place.

[David R]

Cut the tube and replace the hose. I would use automatic transmission hose available from your local parts store like NAPA. I do this a lot. Using the proper clamp makes a big difference. 8mm = 5/16" hose here in america.

I do this a lot with rotted out power steering cooler RETURN lines and engine oil cooler lines (both pressure and return). The automatic transmission cooler line will with stand any oil pressure our bikes can come up with as long as the proper clamps are used.

I have a tool that will put the bubble in the line but yours is too short. I would not worry too much. If it makes you feel better, then can be flared a little with a punch. This makes the hose hard to push on as its thicker and heavier wall than other hose.

Radiator or rubber hose will not work. The oil will eat it up in no time.

David

[Lost Rider]

Some pics:

Closeup of hose and fitting. Note the oil in the crimp on the Oetiker clamp:

Looks to me like it's coming from the radiator since there's oil above the hose and mount and upwind.
If it is leaking where the fitting meets the radiator it seems it could get pushed over to the mount, if it was leaking from the hose it seems doubtful it would get pushed against the wind up and over to the mount, but stranger things have happened.

break out the talcum powder. lol


Sorry to see that Don.

[motoracer8]

Don, I'll bet it is the hose. I worked on Porsche's for 30 years and saw the same type of leak many times.

Rather than replace a expensive oil line assy. I would repair them in the shop. I would cut the crimp off with a cut off wheel and used the same shells and crimping tool used on A/C hoses. The repair looked OE for half the price.

[dbrick]

If it is the hose, another possibility is to find a 8mm nipple, perhaps 30mm long, something like this:

http://llbrass.en.made-in-china.com/pro ... tting.html

Cut the last half-inch of the existing rubber off, exposing a new and undamaged end. Then cut the rubber hose between its newly-cut end and the permanent crimped fitting at the other end, insert the nipple, and clamp. The advantage is it may be easier to find the nipple; the disadvantage is having two additional clamped joints on the right side.

[deilenberger]

It was the clamp. I cleaned it all up and dusted it carefully with "Gold Bond" (anti-monkey-butt-powder, who'da thought?).. and wiped the power around so as to get a nice thin uniform film. This was after I tried tightening the clamp that's on it.

Went out for a ride to see if I could locate some spray cleaner in case the leak came back, and a better designed clamp.

Zilch on the clamp - at least at auto stores. Went to a local NAPA store (generally the place mechanics go) where it took about 30 minutes to determine the only hose clamp they carried that might work was a worn-drive clamp with an inner liner to prevent cutting the hose. It was spec'd for 9 x 22mm in size (on the metric size listing.) Cost was $2.25. Bought one, tossed it in the tank bag. Was going to try buying some spray contact cleaner there, but that would probably take another half-hour, so I skipped it.

Rode to a not so local AutoZone (moderately sized box-store catering to the DIY enthusiast.) Wandered the isles, found their clamp selection was out hanging up on the racks. Spotted some fuel-injection hose clamps that looked close (some closer then others, which was odd since they were all supposed to be the same size.) Sized for 16mm hose, (the inch size is 9/16th-5/8th) but appeared that at least one of them might fit this hose. Cost for 4 - $1.29. Hmmm..

Found the CRC electronic spray cleaner - big spray can, around $6, and then found a section with glues and epoxies. Got some JB-Weld epoxy (always good to have) and some Permatex fuel-tank and radiator repair. This comes in a sort of stick - with a different color center. According to the instructions - you simply kneed it until it's a uniform color then push it on the leak/hole and go away for a while. When you come back magic will have happened and there will be no more leaks.

I left AutoZone roughly $25 lighter then I'd come in.

While in the AutoZone parking lot - I checked the area for dampness, and there was none. None underneath. Nothing at all on the radiator itself (above the mounting bracket where it had appeared wet before.) The talc on the rubber pipe still looked dry.

So - another case of Eilenberger's Laws needing to be expanded. "When you finally obtain all the parts necessary to effect a repair - the need for the repair will disappear." I'm hoping this happens tomorrow when the new caliper for my Porshe arrives.. Just to make sure the leak doesn't return, I'll toss one of the new hose clamps in my tankbag (Eilenberger's Law of Spare Parts: "You never need the part you have..")

I took the long way home - about 20 miles out of my way since it was a very nice day and I had no chores waiting. Got home, nothing had changed. Still looks dry.

I'm going to clean it up again (have LOTS of cleaner to play with) and dust it again. I figure this also gives me an excuse to ride up to the dealer this week and grab a few of the factory clamps - they are $1.06/each according to RealOEM, and a web search disclosed they are used all over BMW cars. Probably on the leaking power-steering hoses that every BMW has.

I think the spread of oil is caused by errant air-currents. While it makes sense that the oil shouldn't blow forward, I could see it seeping out the joint between the hose and elbow on the cooler. The elbow is forward of the hose and from there it might well get blown sideways or who knows where. There are lots of surfaces in the area to deflect air so some turbulence might be expected. Whatever - the radiator appears to be absolutely dry. Whew.

[deilenberger]

If it is the hose, another possibility is to find a 8mm nipple, perhaps 30mm long, something like this:

http://llbrass.en.made-in-china.com/pro ... tting.html

Cut the last half-inch of the existing rubber off, exposing a new and undamaged end. Then cut the rubber hose between its newly-cut end and the permanent crimped fitting at the other end, insert the nipple, and clamp. The advantage is it may be easier to find the nipple; the disadvantage is having two additional clamped joints on the right side.

The other disadvantage is - that's a very short length of hose, and it bends (probably pre-formed) at a 90 degree angle. Take a look at yours - not much room there to splice in a replacement end, and adding more clamped joints makes me think of more possible points of failure. Having once ridden out a fully oiled rear tire on this bike, I'm not too enthusiastic about trying it again.

[Lost Rider]

Glad I was wrong!

[deilenberger]

Joe - Me too!

Just finished playing with it. Cleaned it all up nice and tidy.. then took the screw-clamp from the NAPA parts place and put it on the hose over the ballooned part of the ebow. So I have the original clamp, and a second clamp squishing down some previously unsquished hose. If you looked for it - it might appear to be a hack, but certainly better than 99% of the British bikes I saw at the Gathering last weekend.

Motoracer - do you have a link to the type of clamp you're talking about? Making it look "factory" would be nice...

[dbrick]

The other disadvantage is - that's a very short length of hose, and it bends (probably pre-formed) at a 90 degree angle. Take a look at yours - not much room there to splice in a replacement end, and adding more clamped joints makes me think of more possible points of failure. Having once ridden out a fully oiled rear tire on this bike, I'm not too enthusiastic about trying it again.

I thought about that. If there weren't enough space for the nipple in the horizontal run, then a) put the nipple up on the vertical run, where there's more elbow (shin?) room for the bend below it, or b) find the kind of nipples that screw together into a right angle, and use the metal as the bend.

Still, I like how yours ended up as a loose and fixable clamp.

[motoracer8]

Don, I don't have a link to said parts, but they are available at most auto supply stores. We bought them, the metal shell, by the box in several sizes as we made oil lines and AC hoses in the shop.

The crimping tool was expensive as it comes with several size dies for different size hose.

I'll bet if you removed the oil line and took it to someone who does AC repair they could supply you with a short piece of hose and do the crimp for you. It would be a 20 minute job in my shop.

[deilenberger]

Ordered 4 of the clamps from the dealer yesterday. It has stayed bone dry so far, so the clamp was the problem. I looked at it, and since I couldn't find a wider clamp in that size that seemed "factory" looking, I measured and I can fit two of the original clamps between the blister and the end of the hose. That's my current plan, plus I finally get to use my Oetiker clamp tool..

Will post a photo once I'm done.

[towerworker]

It's no wonder you have a leak. Someone put oil in your radiator. Everyone knows (or almost everyone) that you're supposed to put antifreeze in there.

[deilenberger]

Should follow up.. will have to take photos tomorrow. Plan for 2 clamps worked. The original clamp actually seemed fine once I tightened it up a bit, but figured since I had bought the clamps, and it gave me a chance to use the Oetker tool, what the heck.

What surprised me was how little oil drained out when I disconnected it. 50cc's maybe, probably less. I had expected the entire cooler to have oil in it, but apparently it doesn't once cooled off.

No more leak. Photos to follow..