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Discussion Starter · #1 ·
Hey Folks:

My '82 GL 500 has been guzzling coolant (about a cup needed before each ride). In short, I've tried fixing it (see backstory below) but I think I probably need to take it to a radiator shop in Chicago. Any recommendations for a rad shop in Chicago? (that will accept a motorcycle radiator ... I've called a few and gotten lots of resistance)

Here's the backstory:
Bought the bike November 2013 with 21k miles on it
First highway ride in the spring -- the cooling fan came loose and banged against the backside of the radiator. (First tow truck ride ensued.)
My buddy and I took the radiator off, re-attached the fan, filled the rad back up and I rode it for a week.
Coolant spraying on my boots
Radiator off again, noticed dings and some small leaks on the radiator.
Flushed radiator a few times
Added new coolant and a bandaid fix of some "Barrs Stop Leak" tablets Radiator Stop Leak Tablets (p/n HDC) | Products | Bar's Leaks & Rislone - Premium Automotive Chemicals
Seemed to take care of the problem -- no noticeable leaks
Coolant level still going down -- but bike is not showing signs of overheating
I can't find the leak...

Any suggestions of what I should try next? I'm thinking a radiator flush is in order, and taking it to a radiator shop will be my next move. Please let me know if any of you experienced folks have any insight. Thanks!

TL;DR - Radiator guzzling coolant, but can't find the leak.
 

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There's a GL500 radiator in eBay going for $50 right now. Probably cheaper than a radiator shop.
 

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1) Check the crankcase for an oil milkshake. . . .
2) Look in the overflow bottle for signs of oil.
3) Smell your exhaust fumes, see if you can smell something sweet.

Any one of the above, it's a head gasket.
If not, good.

Next step, warm the engine up, and sniff all around the engine for the same sweet smell above.
(warm coolant has a distinct smell)
 

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Last year I fixed a rad on a KLR with JB Weld. Cleaned the spot with solvent. Then hit it with 2 layers of epoxy. Cheap n easy. K
 

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Whereabouts generally speaking in Chicago do you live. I'm a couple miles east of Midway and I DO have a spare used GL radiator if you're interested in buying one. When I first bought this bike back back in '07 I e-bayed the heck out of used parts for it "just in case' and haven't needed many.

PM me if interested.
 

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Discussion Starter · #7 ·
Thanks for all the feedback, folks. Here's the update:

- Oil looked good as new (Great sign, right? Probably not a headgasket?)
- No steam, smoke or sweet odor coming from exhaust pipes or anywhere that I could smell
- I guess the weep hole could be an issue if it was sealed by the previous owner, but there's no oil in the crankcase, so I'm still a little stumped.

We flushed the rad with water twice, coolant once, and then filled and burped the radiator (ran it with the cap off so the bubble could work its way out to the top). Filled it again and covered the fins. The overflow tank is now up to the full mark too with new coolant.

A bit of a mystery still as to where the coolant is going...

Can anyone tell me how high/full the coolant should be? The tops of the fins need to be completely covered and submerged with coolant, right?

Is there any major risk of riding the bike as long as I keep an eye on the temp? I just don't want to blow a headgasket (but the oil looks great!)

@chicagorandy, I'll PM you.

Thanks folks!
 

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Could be a leaky hose fitting that you can't spot when driving, so get it up on the centerstand and idle it till good and warm and then look close with your worklight at all the fittings.
Maybe you already did this.
It has to be going somewhere unless there's a wormhole in your radiator and it's going to the fourth dimension.
 

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If the temp stays under control then the engin will be fine. You need to add water after the bike has cooled down, not while riding?
 

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get a pressure tester from auto zone advance or orielys

pressure test the cooling system all will be revealed
Let him know the pressure. I think it is less than 15 pounds PSI
 

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if it is not the weeping hole or a visible rad leak a lot of the time it will be a oring at the coolant pipe elbow on the head and teh fan blows all traces away

so that is why a static pressure test will do it

you know each section of the manual has a trouble shooting blurb for each section

section 9-1 bottom of the page for the gl500 cooling

it walks you thru most problems

manuals can be had in the quick reference section under the general section of the forum

https://docs.google.com/folderview?...lLWFiODEtZDQwNmVlNDM5YzE2&usp=drive_web&hl=en







it
 

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Discussion Starter · #14 ·
Thanks folks. I'll check the hose fittings and pick up a pressure tester. I have been noticing that the radiator cap generally has coolant in/on it. Could it be a bad seal on that cap? (just brainstorming here)

I've got the CLYMER for this bike in a paperback in my garage. Keep forgetting to check the PDF Manual on my computer (been meaning to take it to staples to get it printed). Thanks for the reminder.

I appreciate the help in troubleshooting. It's tough to know where to start, so I appreciate the little "check this" "check that" suggestions -- helps me get dialed in.

I'll let you know if I find anything out.
 

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Discussion Starter · #15 ·
$90 - $125 for a pressure tester???
 

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My way to test a radiator
Rad_leak_test.jpg
Costs:
Two bottles of red wine for the two corks,
A nice smiling and loud THANK YOU to the man in the tire/wheel shop for the valve insert,
one Kabelbinder/cable binder/cable tie (We say "Spaghetti" for that white thing to fix the cork near the spark plug).

ToDo List:
File/grind/sand the corky to the diameter of the brass tubes, that they have a good seat in there.
Bore a hole ~ 8mm into the upper cork(y), fix the valve insert in the cork.
Bring less **) than 7 psi into the rad.
Put the rad into a water bowl (Your swimming pool, bathtub...or what else You have) and watch for bubbles.
!!!! Warning !!!Do not bring soap into the water before the test, You don't see radiator bubbles in the bubble bath
**) Less then 7 psi because more isn't necessary.
(At ~~17 psi the overpressure valve in the radiator cap will open, that's not recommended for this test.)

Gruesse
WolFgang

PS: I'm so poor this week ('cause two bottles of red wine) now I don't have the money to buy and to put smileys on the right places.
Cheerio
 

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G'day all.
I've recently joined up with you folks by buying an '83 Interstate and as I live downunder , I guess its now an ex-States Interstate. Shipping was a bit of a hassle, but that's all over, now to the tinkering.
I don't reckon this bike has been run at all in the last 10 years. It's low mileage, around 10,000 from new and will be a sweet thing once all it needs is done.
I got it running today, after cleaning the tank and filters and carbs etc. warmed it up then drained the oil, and its very creamy. Coolant reservoir was a little low but nothing I would have thought real bad.
I've looked around this site and the web, but can't seem to find a good answer. I sure don't think it would be a head gasket, there is some thought on this thread that it might be the mechanical seal? but I'd appreciate some advice. I don't know much about the bike yet. I have a workshop manual, but no help there on this concern
 

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Check that the weep hole under the water pump is clear.
Top up the coolant, run the bike (add new oil if you haven't already).
If the mech seal is leaking, you should see a dribble of coolant on the left side of the motor under the carb.
If the seal is leaking, and the weep hole is blocked, the coolant will force its self past the oil seal on the cam and into the sump. The oil seal is faced to keep the oil out of the coolant, hence coolant will get through into the oil.

Have you joined the Aussie site here: Australian CX500 & CX650 Register - Index
 
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