Chocolate milkshake situation near water pump

[jimbonaut]

Pretty sure this is never a good look...



Ok, rewind a little. I'm working on getting a '76 back on the road, not a full restoration or anything, just hauling a survivor back into roadworthy condition. I've rebuilt the carbs using Randakk's kit and very helpful video instructions, installed a new battery and checked the wiring - got it fired up for the first time last week and although it's running really rough (barely idling) it is at least firing on all four and not blowing too much smoke out the exhaust anymore. So I know the engine's not borked. Plan is to now go over the bike more thoroughly, maybe install a new wiring harness, and then go through the to-do list. Left side valve cover is smoking badly so I'm thinking there's an oil leak there - new gaskets will abound and I already have new timing belts waiting to be installed.

So back to the immediate drama. Noticed this small pool of thick liquid under the left front crankcase, soon determined it was coming from the vent hole on the bottom of the crankcase near the water pump housing. I've since been doing a fair amount of reading of articles both here and on Randakk's blog as to what may be causing this, and it's my understanding that it's probably down to a water pump seal failure, or over-torqued crush washers, or missing o-ring, or the like. From this limited info, do you think I'm on the right page?

Today I'll haul the bike off the work table, stick it on the centre stand, and have a go at removing the radiator in order to access the water pump housing. I'll give the pump a jiggle and check for excessive movement. I don't want to get too far ahead of myself, but, assuming the worst, that pump's going to need replacing right? If so I'll stump up for OEM - I don't want to do this job twice.

What else am I going to need to buy to complete the job? Gaskets, seals and o-rings for sure - can anyone recommend a decent kit for the job? I've read the KP gasket kit is good. Anything else I should buy or will need? Maybe a new set of allen bolts for the front engine case to replace the philips that will no doubt be a bugger to remove?

Many thanks in advance

[pjlogue]

Plan on replacing the water pump and all gaskets/seals. It is a bitch to get a few of the cover JIS screws out. Use a manual impact driver and extension with a JIS bit. The frame interferes with direct access to the screw heads so the extension makes it workable. A few of the JIS screw holes have the holes open on the back side where water/salt/dirt can get into the threads. These were the hardest to remove when I did mine. Make sure the gasket kit has the proper gaskets for thickness. A too thin gasket on the front cover will cause shifting problems because there is very little clearance between the shifting shaft and the front cover.

I bought my replacement pump from Partszilla. Can't remember where I bought the gasket from.

-P.

[Rat]

Good help in ShopTalk too ...

Gord

[5speed]

when you replace, rebuild the pump, replace the 3 small aluminum washers on the 3 screws that hold the pump to the transmission cover or you may end up with oil leaking in to your coolant..ask me how I know.

[jimbonaut]

Anyone thats ever removed the front engine cover from a '76 with its sh*tty phillips bolts knows all too well what a massive pain in the arse it is. So I'll skip the details other than to say I won ugly.

Here's what I'm looking at -



no idea what that sludge is in the pump housing but it felt gritty. The pump looks rusty as all hell and that little hole was full of it -



The pump itself was pretty snug in the case though, no lateral movement at all. I did find a messed up situation with the pump bolts though - one had one crush washer, one had two and one had none at all -



- so that's definitely borked. The bolt with 2 washers had wet oily threads and stunk of old oil. No doubt someone's been in here before, with questionable attention to detail.

Also, a question about these two dowels. Are they supposed to be snug in their case housing? Mine definitely aren't. Also, the o rings on them are loose to the point where I don't think they're the right size even, they seem too big.



With this info, can anyone spot a smoking gun? Anything directly responsible for the milkshake?

I'll buy a new OEM pump and a gasket set with o-rings - if anyone has a suggestion on a good, complete kit to buy I'd appreciate it

Edited to add - I just found an OEM water pump along with all OEM gaskets, seals, o-rings and dowels for what looked like a very fair price on eBay so I think I'm good in that dept.

Also ordered a complete set of stainless steel bolts for the transmission cover. I’ve used them before on other rebuilds - slap some copper anti-seize on the threads and they’re great. One of the Phillips bolts sheared off and is still stuck in the crankcase - got it soaking with PB Blaster and got my fingers crossed. Whoever’s the next guy to have to remove the cover won’t have the same headache I did at least.

[Track T 2411]

Just an FYI, that pump is a replacement. The original pump had a bakelite propeller, not metal. The gritty stuff is probably stop- leak. The crush washers (or absence there of) could be a contributing factor to the 'milkshake,' but I'd say there's a lot of stuff going on in there!
The dowels you reference are not 'locating' dowels, so no, they aren't 'tight' fitting. They are part of the oil passages, and the o-rings seal between the front cover and block. Your gasket kit should include those o-rings.
If it were me, I'd try to flush as much of the cooling system as I could. That grit can't be good...

[jimbonaut]

Thanks, good to know about those dowels. When you say flush the cooling system do you mean the radiator or the system throughout the engine casing as well? Also, what’s “stop-leak”?

[Track T 2411]

Stop- leak products are quick-fixes for coolant leaks. They seldom work and often create other problems, like clogging radiator and other coolant passages. One of the 1100 engines I returned to service had the bottoms of the water jackets nearly full of the stuff. I had to scrape it out with a knife... so, yes, flush the radiator and the block. (My opinion...)

[jimbonaut]

I like the quote in your signature - "If you can't take the time to do it right the first time, how are you ever going to find the time to do it over?" That’s going up on my garage wall, but sweary-er.

I just checked out how to do a coolant flush - fire the bike up and dump some distilled water through the system. Thanks for the advice, I’ll be doing that for sure.

[Rat]

Robin, longtime member here, offers a bolt kit to replace those pesky JIS screws ...

Gord

[ob1quixote]

I like the quote in your signature - "If you can't take the time to do it right the first time, how are you ever going to find the time to do it over?" That’s going up on my garage wall, but sweary-er.

I just checked out how to do a coolant flush - fire the bike up and dump some distilled water through the system. Thanks for the advice, I’ll be doing that for sure.

Sign I saw years ago.
Small, supported text lines of 4 characters

Plan
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[5speed]

anti-seize on all the fasteners is your friend as well.

[redglbx]

Besides the “stop leak” causing the problem, if that bike’s previous owner ran a long term antifreeze with silicates (sand) that was popular when it was new because having the ”sand” flowing around, sandblasting (theroretically) to keep everything clean was the accepted thing back then.

Myself, I have found that using a silicate (i did) antifreeze created a gritty mud in the low area’s particularly in the bottom of the radiator and that gritty mud is a known water pump killer.

So at some point Honda mandated “silicate free” antifreeze that is generally the blue stuff. Track T’s advice on cleaning things is spot on, so while it’s apart clean as much as you can and personally I’d take the radiator to a good radiator shop and have them boil it out & pressure test it and then do the distilled water flush once it’s back together. Replace those JIS screws with Allen heads so if you have to take it apart again it’ll be easier.

Also I’ll add that I’d bet that a good set of JIS screwdrivers would eliminate most of the screw head stripping problem, everyone should have a set and use them, there is a big difference ! My .02

[jimbonaut]

Great info, thanks gents. Also, redglbx - thanks for the nudge to buy some JIS screwdrivers. I've been working over old Hondas with Phillips screwdrivers for too many years now. Just picked up a set.

[Jonesz]

Great info, thanks gents. Also, redglbx - thanks for the nudge to buy some JIS screwdrivers. I've been working over old Hondas with Phillips screwdrivers for too many years now. Just picked up a set.

Thanks for the reminder re the JIS screwdrivers. I for one never touch any of my bikes with a phillips screw driver. JIS tools make all the difference in removing screws from Japanese engineered bikes.
Note to self: "Remember to order some JIS bits for your impact driver".
Edit: Just ordered from Amazon