HONDA GL1000 1975/6 Called Merlin.

[Adamc]

MERLIN HAS WATER PUMP SURGERY

I made a schoolboy error when I first got the bike and flushed the cooling system and refilled with new antifreeze coolant. The old stuff looked like muddy water. Then my water pump started to leak through the weep hole; @Mailman explained the seals had probably failed or were about to fail. I decided to open up the front casing and at first replace the 'O' rings on the water pump.

The water pump casing is in two parts; the front holds the rubber coolant pipe; the main body surrounds the impeller. The original shouldered bolts of the main body were extremely tight; probably never been removed before. Of course one of them sheared off leaving about 3.0mm of thread proud of the body.

OK I will deal with that later.

I watched a few YouTube videos and most said if you open up the front and find an original water pump (plastic impeller) then you may as well buy a new Honda pump; so I did. The UK suppliers of note all wanted £200 - £280 for a genuine Honda pump. I bought a genuine one from an eBay seller in Japan for £142.00 shipped.

(Then I got shafted on top with £40 import tax!!!!!) Still cheaper than UK prices.
Disappointed the unit did not include the two OE O rings! (I already have them from David Silver).

Started the job by draining the (new) coolant and oil, easy peasy.
Then remove the oil filter..... But some gorilla had done it up with a plumbers pipe wrench and scaffold pole and rounded off the bolt head.
I tried all the usual methods, but in the end sacrificed a socket one size smaller and hammered it on. Much yanking and pressure later and it gave way.
Pulled the filter housing off and the retaining bolt had some 'burrs' and damaged threads. New one ordered from Honda Classics for £22.95 (David Silver Parts £39.00 + VAT!).

Removed the front of the water housing case and of course one old bolt sheared off. It was easier to remove the radiator and associated plumbing to gain access to the front engine cover.

Access to most of the JIS screws is OK; but the top run of bolts is impeded by the frame crossrail. Now way to get an impact hammer with JIS tip in there.
Some creative work with slim wobble extensions and a Birmingham Screwdriver (Fu(kin' Big Hammer ? BFH) sorted that out. The front cover was well stuck to the engine. Lots of soft faced hammer action and the seal broke away eventually. A bit of wiggle action and the casing came away.

Lower front engine after casing removal

Frame cross member impeded access to the top row of retaining bolts.

You can see the plastic impeller and broken stud just below it. The old gasket material came away with some judicious but careful scraping.
Then the manual states "Simply drift the waterpump out of the housing, do not hit the spindle". I tried various 'simple drift' techniques to no avail.
So I supported the casing between two blocks of wood and sharply hit the spindle with the Birmingham Screwdriver! (BFH). Job done.

Old and new pumps together; new one has metal impeller.

Above you can see the failed 'O' ring where the pump butts up to the casing.

On to the broken stud.
A number of YouTube videos offered differing ways to remove the broken stud.
1. Shock the stud (Tap with punch) and use vice grips to extract. (No Joy)
2. Add heat and use vice grips to extract. (No Joy)
3. Double nut the stud and two spanners to extract (Not enough stud)
4. Center drill stud and use extractor (tried several No Joy)

So I decided to use a larger 4.0mm drill bit and collapse the remaining stud. This was risky as I may have damaged the casing thread.
However my drilling skills were equivalent to a master mechanic; or I was just very lucky!
I ran an M6 tap down the hole to clean up the threads, and tested with a new M6 cap head bolt.

Happy to say the thread is fine.

Next I will clean the casing and associated pump parts.
Reassembly on my next post.
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[Raymond]

Ads, thinking back to when you came to this forum, may I say you have come a very long way since then with the open-engine surgery work you take on and the methods you devise to deal with the inevitable buggerations that arise.

 

[Adamc]

Ads, thinking back to when you came to this forum, may I say you have come a very long way since then with the open-engine surgery work you take on and the methods you devise to deal with the inevitable buggerations that arise.

Thanks for the kind words Raymond. I have to say you and the guys on the forum contributed so much, and gave me the confidence to at least try things.
YouTube has also offered me guidance; if you don't know, you can find out. 'Buggerations' is a great word which I seem to be finding more of each day!

 

[650Skull]

'Buggerations' is a great word

Been following and amazed as well.kudos.

Word of advice........write Buggerations
on all beer cans an on the computer screen for future reference

 

[Its been a long time]

Well done indeed on the stud fix. I wouldn't have trusted myself to do that. I'd have put the thing on a vertical mill and machined it out. So, full marks for doing it without that level of complication!

 

[TX650A Van Islander]

Some fine work!

 

[Adamc]

Well done indeed on the stud fix. I wouldn't have trusted myself to do that. I'd have put the thing on a vertical mill and machined it out. So, full marks for doing it without that level of complication!

I would love a vertical mill and a lathe (Dad had both but they got nicked from his workshop after he passed away ). Don't even have a pillar drill.
Thanks for the nice words. And to @TX650A Van Islander also.

 

[Its been a long time]

I would love a vertical mill and a lathe (Dad had both but they got nicked from his workshop after he passed away ). Don't even have a pillar drill.
Thanks for the nice words. And to @TX650A Van Islander also.

Unfortunately I no longer have access to machine tools either. It's only when you don't have something, you realise how much you miss them. Anyway, well done with that.

 

[Adamc]

More Water Pump Action

A lot of cleaning and removal of gunk from components, which takes longer than it should even with solvents and scrappers.
But perseverance is the key. Once all the old gasket crap was off I cleaned up the surfaces with 2000 &3000 grit wet & dry to a nice finish.

Casings Before:

On the last images you can see the paint peeling up; looks like it was flashed over with 'Silver Wheel Paint' and no primer.
Time for a bit of Dremmel & wire brush treatment; that soon got it back to bare metal. Some primer and a coat of engine silver and it looked much better.

Casings After:

Third image shows the new water pump installed with genuine Honda 'O' rings. Neither Haynes or the Genuine Honda workshop manuals give the torque setting for these bolts! Robert Kramer (USA) on YouTube has good videos and tech detail for older Goldwings, so its 10-11Nm he recommends.

Cleaning the surfaces under the bike on its centre stand was a bloody pain (at my youthful age), but I can't fit in a table lift in the shop.
Below with old seals in place and much crap.

Next was to install the 'O 'rings to the cleaned engine casings together with a new gasket; and a new seal for the water-pump drive shaft.
Time to offer up the assembled water pump casing to the engine. A fiddle to get the pump driveshaft engaged, and pop its in place.

You may notice I have reused the original JIS screws in the image above; not my plan or preference.
I did buy a complete set of stainless bolts for this engine to improve the cosmetic look and easy removal if required at a later date.

Sadly they were all the wrong length to be of any use . Old and new shown above for comparison.

I emailed the seller as below and the reply I got.

The Honda 'guru' may have given mis-information if he left on bad terms, or its just an excuse for poor service.
Always easier to blame someone else. Will they refund my return postage?

I could have buttoned this up today; but I'm now contemplating whether to get another bolt set from elsewhere.
More to come.
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[Its been a long time]

@Adamc frustrating like crazy when you get something like that. FWIW, I don't ever buy kits of screws. I make a list and buy them as required. I have good experience with an eBay seller called kayfast1. I buy all my screws etc from them. Might not be the absolute cheapest solution to your problem but it's an option for you to consider.

 

[Jim]

FWIW, I don't ever buy kits of screws. I make a list and buy them as required.

Yep, that's how I do it also. Whenever I've bought a "kit" of anything... it seldom work out. Much easier to research on your own and order singles. Make your own set, as it were.

Don't know what shipping would be like, but Bolt Depot has very good prices on stainless bolts...

https://boltdepot.com/Metric_socket_cap_Stainless_steel_18-8_(A-2)_6mm_x_1.0mm

 

[Adamc]

@Adamc frustrating like crazy when you get something like that. FWIW, I don't ever buy kits of screws. I make a list and buy them as required. I have good experience with an eBay seller called kayfast1. I buy all my screws etc from them. Might not be the absolute cheapest solution to your problem but it's an option for you to consider.

I keep learning every day.....

 

[Jim]

Oops, my bad. They only ship to the US, Canada and Mexico.

 

[Adamc]

Oops, my bad. They only ship to the US, Canada and Mexico.

View attachment 352193

OK I'm sure I can get some in the UK.

 

[Its been a long time]

I keep learning every day.....

 

[Highpower]

Something to consider is that common stainless cap screws are more brittle than the steel screws Honda used and are more likely to gall up in aluminum threads without lubricant. For that reason, I won't use them in any critical area where strength is a concern, nor will I use them in aluminum threads. I would try to source a set of steel cap screws by measuring your originals and ordering steel allen head screws in the proper length.

Here across the pond, we have several hardware stores that have assortments of screws, bolts and washers in different materials and finishes. Do you have similar stores in your area where you can source hardware?

BTW, I am extremely jealous of your GL1000. Before I picked up my XS, a naked GL1000 was on my short list of bikes I was looking for. Everyone I found was either way too expensive and had been pimped out with a Vetter Windjammer fairing and some kind of ugly "touring" seat. and had been parked for many years. Or, the poor bike had been left out behind garage to weather with little regard to preserving it, again for many years. Generally speaking it was both.

 

[Adamc]

Something to consider is that common stainless cap screws are more brittle than the steel screws Honda used and are more likely to gall up in aluminum threads without lubricant. For that reason, I won't use them in any critical area where strength is a concern, nor will I use them in aluminum threads. I would try to source a set of steel cap screws by measuring your originals and ordering steel allen head screws in the proper length.

Here across the pond, we have several hardware stores that have assortments of screws, bolts and washers in different materials and finishes. Do you have similar stores in your area where you can source hardware?

BTW, I am extremely jealous of your GL1000. Before I picked up my XS, a naked GL1000 was on my short list of bikes I was looking for. Everyone I found was either way too expensive and had been pimped out with a Vetter Windjammer fairing and some kind of ugly "touring" seat. and had been parked for many years. Or, the poor bike had been left out behind garage to weather with little regard to preserving it, again for many years. Generally speaking it was both.

Thanks so much for your input which is most welcome.

I agree with your observations. My intention was to lubricate the stainless threads before use. They only require 10 Nm of torque to seat them in the casings so not a lot. As it is the Honda screws are back in place and may stay.

My bike came to me via another UK owner, originally a USA import to Blighty. 15,000 miles, ran like shit when I got it; but that’s all in my build thread above.

Cheers
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[Mailman]

Wow Adam! That water pump repair is really making you work for it! With regard to your seized bolt, that kind of stuff makes me crazy, and in turn I get a little heavy handed with the anti seize on any bolt going back in. Love that stuff!
You’re doing a great job and I’m enjoying following along from afar!

 

[Adamc]

More Water Pump Action

A lot of cleaning and removal of gunk from components, which takes longer than it should even with solvents and scrappers.
But perseverance is the key. Once all the old gasket crap was off I cleaned up the surfaces with 2000 &3000 grit wet & dry to a nice finish.

Casings Before:
View attachment 352174View attachment 352175

View attachment 352176View attachment 352177
On the last images you can see the paint peeling up; looks like it was flashed over with 'Silver Wheel Paint' and no primer.
Time for a bit of Dremmel & wire brush treatment; that soon got it back to bare metal. Some primer and a coat of engine silver and it looked much better.

Casings After:
View attachment 352179View attachment 352180View attachment 352181
Third image shows the new water pump installed with genuine Honda 'O' rings. Neither Haynes or the Genuine Honda workshop manuals give the torque setting for these bolts! Robert Kramer (USA) on YouTube has good videos and tech detail for older Goldwings, so its 10-11Nm he recommends.

Cleaning the surfaces under the bike on its centre stand was a bloody pain (at my youthful age), but I can't fit in a table lift in the shop.
Below with old seals in place and much crap.
View attachment 352182

Next was to install the 'O 'rings to the cleaned engine casings together with a new gasket; and a new seal for the water-pump drive shaft.
Time to offer up the assembled water pump casing to the engine. A fiddle to get the pump driveshaft engaged, and pop its in place.
View attachment 352183

You may notice I have reused the original JIS screws in the image above; not my plan or preference.
I did buy a complete set of stainless bolts for this engine to improve the cosmetic look and easy removal if required at a later date.
View attachment 352185
Sadly they were all the wrong length to be of any use . Old and new shown above for comparison.

I emailed the seller as below and the reply I got.
View attachment 352187
The Honda 'guru' may have given mis-information if he left on bad terms, or its just an excuse for poor service.
Always easier to blame someone else. Will they refund my return postage?

I could have buttoned this up today; but I'm now contemplating whether to get another bolt set from elsewhere.
More to come.
Ads.

FAIR PLAY AND A REFUND TOO.

After a bit of back and forth dialogue; I have to admit the seller of the bolt kit proved to be very helpful.
They had agreed a refund and offered this solution below.

By this time I had already cleaned up the Honda originals and reinstalled them, so refused their offer.
I did say I would consider the above option in future however. Their reply:

Yesterday I had boxed up all of the Waterworks on Merlin and went on to fill the cooling system with the correct fluids.
Imagine my horror to find the bloody coolant pissing out of the housing I had just installed.
Back under the bike I drained the coolant, removed all the bolts and the housing to find the new gasket had been torn on installation.

Luckily I had another new gasket on my shelf.
Today (Friday) I cleaned up all the surfaces (again!), and reinstalled the housing with even more care.
I did put a smear of water proof sealant both sides of the gasket as recommended in the manual.
I will leave for 24 hours to cure before refilling with new coolant. Oh the frustration & expense!.