► Radiator top hose failures

[Ed@Ford]

EVERYWHERE:
When you do rip into the housing, please document(photograph) the end where the hose slips on and tell us if it is deformed as shown in post #85. Also as I suggested previously, deepen(file/sand) the "barb" where it is deformed, and if possible make the step sharper and deeper.

I have also wondered if part of the issue with using a jubilee clamp is that it may be too wide and be partially on the step of the housing barb, thus loosing some of it's effectiveness. American versions of the "jubilee" (hose) clamps run about 13mm wide....I've seen german hose clamps that are about 8mm wide. This would allow for a little more room to get the clamp location "just right" to make sure it pinches after the step on the barb.

Finally, I'm only guessing on how much coolant will leak out (My F650 is stillon order) but I would expect the expansion/overflow bottle will want to drain for sure....this might be 500ml (2 cups) of coolant. Besides....coolant is deadly poison to dogs (it tastes like candy to them) so you don't want to spill any.

 

[everywherevirtually]

EVERYWHERE:
When you do rip into the housing, please document(photograph) the end where the hose slips on and tell us if it is deformed as shown in post #85. Also as I suggested previously, deepen(file/sand) the "barb" where it is deformed, and if possible make the step sharper and deeper.

I have also wondered if part of the issue with using a jubilee clamp is that it may be too wide and be partially on the step of the housing barb, thus loosing some of it's effectiveness. American versions of the "jubilee" (hose) clamps run about 13mm wide....I've seen german hose clamps that are about 8mm wide. This would allow for a little more room to get the clamp location "just right" to make sure it pinches after the step on the barb.

Finally, I'm only guessing on how much coolant will leak out (My F650 is stillon order) but I would expect the expansion/overflow bottle will want to drain for sure....this might be 500ml (2 cups) of coolant. Besides....coolant is deadly poison to dogs (it tastes like candy to them) so you don't want to spill any.

Ed@Ford I can tell you from my last mod and YouTube vid I did that there's not enough pipe for the jubilee clip to sit firmly on the pipe and behind the barb. It's fine on the bit that faces you as you do the repair but on the far side it's useless.

I've just been out to check. my Jubilee clip is 12mm wide. I got it from B&Q in the UK which is owned or soon to be owned by Home depot so sizings should be similar.

I'll be sure to document my third fix

 

[Ed@Ford]

Everywhere:
I know for sure those narrow clamps are unique to the automotive industry. You'd never find them at Home Depot here. I work in an engine test laboratory, and only see them on european (German) test engines. I suggest going to an auto parts store and explain your problem to the parts guy. I'm assuming this is a pretty large clamp...like 35mm OD or so. Narrow ones here are available for maybe 15mm or 20mm OD hoses...usually fuel lines....BUT if there is room available you can daisy-chain them together. A solution that is WAY out on the fringe is to get some fat stainless safety wire (1mm?) and VERY carefully safety wire the hose in place. I'd do 2 separate wraps. The danger is that if the safety wiring is not done perfectly(i.e. too tight), you run the chance of cutting the hose.

 

[everywherevirtually]

EVERYWHERE:
When you do rip into the housing, please document(photograph) the end where the hose slips on and tell us if it is deformed as shown in post #85. Also as I suggested previously, deepen(file/sand) the "barb" where it is deformed, and if possible make the step sharper and deeper.

Hi Ed, today I was at a local bike event and my dealer was there. He immediately brought up the subject of the radiator top hose. I said funny you should mention that. The dealership was 5 minutes from the exhibition centre so I headed down there and they fixed it on warranty. To be honest it looks like the original but the hose is softer. I will watch this closely. The mechanic said he sanded down the pipe and used a stronger clip. Again it looks like the old clip. If it fails again I will be doing what you mentioned above and documenting it.

 

[moto1527]

Hi Ed, today I was at a local bike event and my dealer was there. He immediately brought up the subject of the radiator top hose. I said funny you should mention that. The dealership was 5 minutes from the exhibition centre so I headed down there and they fixed it on warranty. To be honest it looks like the original but the hose is softer. I will watch this closely. The mechanic said he sanded down the pipe and used a stronger clip. Again it looks like the old clip. If it fails again I will be doing what you mentioned above and documenting it.

I had my hose changed a good 2500 miles ago and i keep checking it- looks fine so far

10250miles and counting

M

 

[John Armstrong]

2500 miles, 2 months, no movement on the hose

 

[Ed@Ford]

Hi Ed, today I was at a local bike event and my dealer was there. He immediately brought up the subject of the radiator top hose. I said funny you should mention that. The dealership was 5 minutes from the exhibition centre so I headed down there and they fixed it on warranty. To be honest it looks like the original but the hose is softer. I will watch this closely. The mechanic said he sanded down the pipe and used a stronger clip. Again it looks like the old clip. If it fails again I will be doing what you mentioned above and documenting it.

So....do I have this right...new hose, "similar looking clamp"...on warranty?

Not all bad. Decent dealer!

 

[everywherevirtually]

So....do I have this right...new hose, "similar looking clamp"...on warranty?

Not all bad. Decent dealer!

They're a pretty good dealer. I know everyone has a different experience with their dealer but Williams in Manchester are pretty good in my book

no doubt someone will be along in a minute to prove me wrong or correct

 

[John Armstrong]

They're a pretty good dealer. I know everyone has a different experience with their dealer but Williams in Manchester are pretty good in my book

no doubt someone will be along in a minute to prove me wrong or correct

Is yours a yellow F800 that was parked about as far as you could from the GMEX centre entrance?

 

[rin_sun]

top hose

After the fiasco with the fuel gauge twice running out of fuel while overtaking at 70! I got to work to see coolant coming out …
North Oxford fix said the best thing they could do would be superglue the hose before putting the clip back on, this clip is a jubilee clip that had been put on because I'd noticed the hose creeping off some weeks previously. The reason for telling you this as we had a bit of a discussion about why it's happening to some bikes and not others. Maybe it depends on how hot the bike gets, mine had been sitting long enough for the fan to come on, this happens quite a lot because I leave the bike running to see to open the gate when I get home in the dark and I'd also been in a lot of traffic queues that day. So watch it if the bike's been hot.
I was so pleased they came and fetched it, brought it back by the end of the day at work. Phew.
I'm really sorry that I've had so many problems with it because it's a superb bike.
Catherine.

 

[Ed@Ford]

I just realized we all might be looking at this hose blow off issue incorrectly. We talk about the hose being too short, too stiff, bad clamp, bad snout on the waterpump housing. Has this issue been specific to the 650 or the 800 or both? Well, each model has a different radiator....thus...probably...and I'll check this later...different hoses. The 650 has a smaller radiator. Maybe the 650 runs a bit hotter than the 800. That's one thing.

BUT, what comes to mind now, after Rin_Sun's comment about the fan coming on...is pressure. Pressure is what wants to pull the hose off when the hose gets hot and soft. What controls pressure?....the radiator cap! Has anyone had their radiator cap checked for popoff pressure? In the US I've seen little fixtures you put the radiator cap in....and it has a gage and you pump up the pressure. Most caps are labeled 1.2, 1.3, or so bar relief pressure. My KTM loved to overheat and boil over...it had a 1.2 cap....there was a Toyota car thermostat available at the auto parts store that was a 1.3 or 1.4. Put that on the KTM...no more puking coolant on your boots. Is there a thermostat check procedure in the F800 manual?

 

[Ed@Ford]

A quick checkof the parts books shows the two hoses to the radiator are different between the 650 and 800...likewise the hose to the overflow tank are different, and of course the radiator. Thermostat & cap are all the same

Is this hose issue specific to 800 or BOTH 800 and 650?

 

[John Armstrong]

Is this hose issue specific to 800 or BOTH 800 and 650?

650 - 2500 miles, so far so good. Never gets very hot as most of my commute is motorway.

 

[Tim Cullis]

It happens with both models. I reckon the problem is down to two issues.

1. The water pump stub needs a flange all the way round
2. The hoses get very soft when hot which encourages slippage

In the meantime, BMW is relying on some Dutch kids to stick their fingers in the dyke.

Tim

 

[moto1527]

650 - 2500 miles, so far so good. Never gets very hot as most of my commute is motorway.

I went to europe last june on the 800 and in s.germany and switzerland it was 36C with oh so slow roads in the lowlands, it was like this for days i didnt get the problem then or later at the "Hog the Bridge" where like thousands of other bikers i crawled upto the start line, Fan came on but no blown hoses

It was later after an normal commute home in Oct (i think) that i noticed the hose coming off.
Ive noticed that the Hose seems to shrink a liitle, its about 4mm shorter now than when it was first replaced- mind you thats still about 12mm longer than the original hose and it has got any smaller in the last month- I'll keep an eye on it though.

M

 

[Ed@Ford]

Very high temperature (177C) silicon coolant hose can be bought by the foot from many places. I've found it for $5 to $20 per foot. I'm guessing the offending hose is 1" ID (25mm). Is the existing hose quite straight? The fiche picture looks more or less straight. I'll bet this material is WAY higher quality material than stock.

 

[rin_sun]

not slipping

It does appear that the hose shortens, maybe because it has expanded in diameter. Gary is convinced that a longer hose would solve the problem.
Catherine

 

[rin_sun]

Back to the hose issue

Yesterday I rode 75 miles or so back to Abingdon from Birmingham. When I got back the coolant hose had crept a good 1/4 inch along the pipe. No sign of coolant so I rang BMW and they put a 'new' hose on for me, don't know whether this is the same material or something else, it has been supplied by BMW and the dealer didn't know whether it was the same material or something that might not stretch as much. It has been glued on again, but the last glue only lasted 3 weeks and about 150 miles …
Anyone else had a dealer supply a new hose or heard of a permanent fix?
How many 800s are doing this and if some aren't why aren't they?
Catherine.

 

[moto1527]

Yesterday I rode 75 miles or so back to Abingdon from Birmingham. When I got back the coolant hose had crept a good 1/4 inch along the pipe. No sign of coolant so I rang BMW and they put a 'new' hose on for me, don't know whether this is the same material or something else, it has been supplied by BMW and the dealer didn't know whether it was the same material or something that might not stretch as much. It has been glued on again, but the last glue only lasted 3 weeks and about 150 miles …
Anyone else had a dealer supply a new hose or heard of a permanent fix?
How many 800s are doing this and if some aren't why aren't they?
Catherine.

Hi Catherine,

ive had my hose replaced with a "longer" " New" one too, several thousand miles down the road all appears to be well, im trying to find out if this happens to the 800ST or if its confined to the GS model.

M

 

[moto1527]

Hi Catherine,

ive had my hose replaced with a "longer" " New" one too, several thousand miles down the road all appears to be well, im trying to find out if this happens to the 800ST or if its confined to the GS model.

M

Welllll, further to my last, my new hose is now shrinking back, about 6-8mm i reckon from new, no leakage yet but its going back in to Bath Rd Bristol Motorrad (excellent guys) for another new hose.

I hope that BMW will have realised something is amiss by now and will sort out the problem

Moto